Engine Management GEN IV V8 – Diagnostics Page 6C4-2–1
Page 6C4-2–1
Section 6C4-2
Engine Management GEN IV V8 –
Diagnostics
ATTENTION
Before performing any service operation or other procedure described in this Section, refer to 00 Warnings,
Cautions and Notes for correct w o rkshop practices with regard to safety and/or property damage.
1 General Information.............................................................................................................................13
1.1 Diagnostic System Check................................................................................................................................... 13
1.2 Diagnostic Trouble Code Tables........................................................................................................................ 14
1.3 Multiple DTCs Fault Condition............................................................................................................................ 15
1.4 Symptoms Diagnostics ....................................................................................................................................... 16
1.5 Diagnostic Trouble Codes .................................................................................................................................. 17
Type A – Emission Related DTCs....................................................................................................................... 17
Type B – Emission Related DTCs....................................................................................................................... 17
Conditions for Clearing Type A or Type B DTCs.............................................................................................. 17
Type C – Non-Emission Related DTCs............................................................................................................... 18
Condition for Clearing the Type C DTCs.......................................................................................................... 18
Current DTCs........................................................................................................................................................ 18
History DTCs........................................................................................................................................................ 18
2 Wiring Diagrams and Connector Charts............................................................................................19
2.1 Wiring Diagrams .................................................................................................................................................. 20
2.2 Connector Chart................................................................................................................................................... 27
3 Diagnostic Starting Point ....................................................................................................................29
3.1 Basic Requirements ............................................................................................................................................ 29
Basic Know ledge Required................................................................................................................................. 29
Basic Tools Required .......................................................................................................................................... 29
3.2 Diagnostic Precautions....................................................................................................................................... 30
3.3 Preliminary Checks.............................................................................................................................................. 31
3.4 Diagnostic System Check................................................................................................................................... 32
4 Symptom Diagnostics.................................................................................................................................33
4.1 Symptom Diagnosis Table.................................................................................................................................. 33
4.2 Intermittent Fault Conditions.............................................................................................................................. 34
Description........................................................................................................................................................... 34
Diagnostic Table.................................................................................................................................................. 34
4.3 Backfire................................................................................................................................................................. 36
Description........................................................................................................................................................... 36
4.4 Cranks but does not run ..................................................................................................................................... 38
Definition .............................................................................................................................................................. 38
4.5 Cuts Out, Misses.................................................................................................................................................. 39
Description........................................................................................................................................................... 39
4.6 Detonation/Spark Knock ..................................................................................................................................... 41
Description........................................................................................................................................................... 41
4.7 Dieseling, Running on......................................................................................................................................... 42
Description........................................................................................................................................................... 42
4.8 Hard Start.............................................................................................................................................................. 43
Definition .............................................................................................................................................................. 43
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–2
Page 6C4-2–2
4.9 Hesitation, Sag and Stumble .............................................................................................................................. 44
Description........................................................................................................................................................... 44
4.10 Lack of Pow er, Sluggishness or Sponginess ................................................................................................... 45
Description........................................................................................................................................................... 45
4.11 Poor Fuel Economy............................................................................................................................................. 46
Description........................................................................................................................................................... 46
4.12 Rough, Unstable, Incorrect Idle or Stalling ....................................................................................................... 48
Description........................................................................................................................................................... 48
4.13 Surges / Chuggles ............................................................................................................................................... 50
Description........................................................................................................................................................... 50
4.14 Fuel Pump Not Operating.................................................................................................................................... 52
Circuit Description............................................................................................................................................... 52
Fuel Pump Not Operating Diagnostic Aids........................................................................................................ 52
Additional Information....................................................................................................................................... 52
Test Description ............................................................................................................................................... 52
Fuel Pump Not Operating Diagnostic Table...................................................................................................... 52
4.15 Fuel Pump Continuously Operating................................................................................................................... 55
Circuit Description............................................................................................................................................... 55
Fuel Pump Continuously Operating Diagnostic Aids....................................................................................... 55
Additional Information....................................................................................................................................... 55
Test Description ............................................................................................................................................... 55
Fuel Pump Continuously Operating Fault Condition Diagnostic Table.......................................................... 55
4.16 Automatic Transmission Functional Check procedure.................................................................................... 57
Description........................................................................................................................................................... 57
4.17 Automatic Transmission Power / Economy Switch.......................................................................................... 60
Circuit Description............................................................................................................................................... 60
Automatic Transmission Power / Economy Switch Diagnostic Aids.............................................................. 60
Additional Information....................................................................................................................................... 60
Automatic Transmission Power / Economy Switch Diagnostic Table............................................................ 60
5 Functional Checks ...............................................................................................................................62
5.1 General Information............................................................................................................................................. 62
5.2 Fuel Injector Coil Test ......................................................................................................................................... 63
Engine Coolant Temperature Between 10 – 35°C............................................................................................ 63
Engine Coolant Temperature Outside 10 – 35°C ............................................................................................. 64
5.3 Fuel Injector Balance Test .................................................................................................................................. 67
Fuel Injector Balance Test – With Tech 2 .......................................................................................................... 67
Fuel Injector Balance Test – Without Tech 2..................................................................................................... 67
Fuel Injector Pressure Drop Calculation........................................................................................................... 69
Fuel Injector Pressure Drop Analysis ............................................................................................................... 69
5.4 Fuel Injector Leak Down Test ............................................................................................................................. 70
5.5 Alcohol/Contaminants in Fuel Diagnosis .......................................................................................................... 72
Without Special Tool ........................................................................................................................................... 72
Description ....................................................................................................................................................... 72
Alcohol in Fuel Testing Procedure.................................................................................................................... 72
Particulate Contaminants in Fuel Testing Procedure ....................................................................................... 72
With Special Tool................................................................................................................................................. 72
Description ....................................................................................................................................................... 72
Test Procedure................................................................................................................................................. 73
5.6 Crankshaft Position (CKP) System Variation Learn Procedure....................................................................... 74
Description........................................................................................................................................................... 74
5.7 Electronic Ignition (EI) System Diagnosis......................................................................................................... 75
Circuit Description............................................................................................................................................... 75
Additional Information......................................................................................................................................... 75
Test Description................................................................................................................................................... 75
Diagnostic Table.................................................................................................................................................. 75
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–3
Page 6C4-2–3
6 Diagnostic Trouble Code Tables........................................................................................................78
6.1 DTC List in Ascending Order.............................................................................................................................. 78
6.2 DTC P0016............................................................................................................................................................ 86
DTC Descriptor..................................................................................................................................................... 86
Circuit Description............................................................................................................................................... 86
Conditions for Running the DTC........................................................................................................................ 86
DTC P0016 ...................................................................................................................................................... 86
Conditions for Setting the DTC .......................................................................................................................... 86
Conditions for Clearing the DTC........................................................................................................................ 86
Additional Information......................................................................................................................................... 86
Test Description................................................................................................................................................... 86
DTC P0016............................................................................................................................................................ 87
6.3 DTC P0030, P0036, P0050 P0053, P0054, P0056, P0059, P0060, P0135, P0141, P0155, P0161...................... 88
DTC Description................................................................................................................................................... 88
Circuit Description............................................................................................................................................... 88
Additional Information......................................................................................................................................... 88
Conditions for Running the DTC........................................................................................................................ 89
Conditions for Setting the DTC .......................................................................................................................... 89
DTC P0030, P0036, P0050 or P0056 .............................................................................................................. 89
DTC P0053, P0054, P0059, P0060.................................................................................................................. 89
DTC P0135, P0141, P0155, P0161.................................................................................................................. 89
Conditions for Clearing the DTC........................................................................................................................ 89
Test Description................................................................................................................................................... 89
DTC P0030, P0036, P0050, P0053, P0054, P0056, P0059, P0060, P0135, P0141, P0155, P0161 Diagnostic
Table................................................................................................................................................................ 89
6.4 DTC P0068............................................................................................................................................................ 91
DTC Descriptor..................................................................................................................................................... 91
Circuit Description............................................................................................................................................... 91
Conditions for Running the DTC........................................................................................................................ 91
DTC P0068 ...................................................................................................................................................... 91
Conditions for Setting the DTC .......................................................................................................................... 91
DTC P0068 ...................................................................................................................................................... 91
Conditions for Clearing the DTC........................................................................................................................ 91
Additional Information......................................................................................................................................... 91
Test Conditions.................................................................................................................................................... 91
DTC P0068............................................................................................................................................................ 92
6.5 DTC P0101, P0102, P0103, P1101 ....................................................................................................................... 93
DTC Descriptors................................................................................................................................................... 93
Circuit Description............................................................................................................................................... 93
Conditions for Running the DTC........................................................................................................................ 93
DTC P0101 ...................................................................................................................................................... 93
DTC P0102 ...................................................................................................................................................... 93
DTC P0103 ...................................................................................................................................................... 93
DTC P1101 ...................................................................................................................................................... 94
Conditions for Setting the DTC .......................................................................................................................... 94
DTC P0101 ...................................................................................................................................................... 94
DTC P0102 ...................................................................................................................................................... 94
DTC P0103 ...................................................................................................................................................... 94
DTC P1101 ...................................................................................................................................................... 94
Additional Information......................................................................................................................................... 94
DTC P0101 to P0103 and P1101 Diagnostic Table............................................................................................ 95
6.6 DTC P0106, P0107, P0108.................................................................................................................................... 97
DTC Description................................................................................................................................................... 97
Circuit Description............................................................................................................................................... 97
Conditions for Running the DTC........................................................................................................................ 97
DTC P0106 ...................................................................................................................................................... 97
DTC P0107 ...................................................................................................................................................... 97
DTC P0108 ...................................................................................................................................................... 97
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Page 6C4-2–4
Conditions for Setting the DTC .......................................................................................................................... 98
DTC P0106 ...................................................................................................................................................... 98
DTC P0107 ...................................................................................................................................................... 98
DTC P0108 ...................................................................................................................................................... 98
Conditions for Clearing DTCs ............................................................................................................................. 98
Additional Information......................................................................................................................................... 98
Test Description................................................................................................................................................... 98
Diagnostic Table for DTCs P0106, P0107 and P0108........................................................................................ 99
6.7 DTC P0112, P0113, P1101.................................................................................................................................. 101
DTC Description................................................................................................................................................. 101
Circuit Description............................................................................................................................................. 101
Conditions for Running the DTC...................................................................................................................... 101
DTC P0112 .................................................................................................................................................... 101
DTC P0113 .................................................................................................................................................... 101
Conditions for Setting the DTC ........................................................................................................................ 101
DTC P0112 .................................................................................................................................................... 101
DTC P0113 .................................................................................................................................................... 101
Conditions for Clearing the DTCs .................................................................................................................... 102
Additional Information....................................................................................................................................... 102
Test Description................................................................................................................................................. 102
Diagnostic Table for the Intake Air Temperature Sensor Circuit DTCs......................................................... 102
6.8 DTC P0116, P0117, P0118, P0128, P1258......................................................................................................... 104
DTC Descriptors................................................................................................................................................. 104
Circuit Description............................................................................................................................................. 104
Conditions for Running the DTC...................................................................................................................... 104
DTC P0116 .................................................................................................................................................... 104
DTC P0117, P0118 and P1258...................................................................................................................... 104
DTC P00128................................................................................................................................................... 104
Conditions for Setting the DTC ........................................................................................................................ 104
DTC P0116 .................................................................................................................................................... 104
DTC P0117 .................................................................................................................................................... 104
DTC P0118 .................................................................................................................................................... 104
DTC P0128 .................................................................................................................................................... 104
DTC P1258 .................................................................................................................................................... 104
Conditions for Clearing the DTC...................................................................................................................... 105
Additional Information....................................................................................................................................... 105
Test Description................................................................................................................................................. 105
DTC P0116, P0117, P0118, P0128 and P1258 Diagnostic Table..................................................................... 105
6.9 DTC P0120, P0121, P0122, P0123, P0220, P0222, P0223, P1516, P2101, P2135............................................ 107
DTC Descriptors................................................................................................................................................. 107
Circuit Description............................................................................................................................................. 107
Conditions for Running the DTC...................................................................................................................... 107
DTC P0120, P0121 or P0220......................................................................................................................... 107
DTC P0122, P0123, P0222 and P0223.......................................................................................................... 107
Conditions for Setting the DTC ........................................................................................................................ 107
DTC P0120 .................................................................................................................................................... 107
DTC P0121 .................................................................................................................................................... 108
DTC P0122 .................................................................................................................................................... 108
DTC P0123 .................................................................................................................................................... 108
DTC P0222 .................................................................................................................................................... 108
DTC P0223 .................................................................................................................................................... 108
DTC P1516 .................................................................................................................................................... 108
DTC P2101 .................................................................................................................................................... 108
DTC P2138 .................................................................................................................................................... 108
Conditions for Clearing the DTC...................................................................................................................... 108
Additional Information....................................................................................................................................... 108
Test Description................................................................................................................................................. 109
Diagnostic Table for the TP Sensor Circuit DTCs........................................................................................... 109
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Page 6C4-2–5
6.10 DTC P0131, P0132, P0133, P0134, P0137, P0138, P0140, P0151, P0152, P0153, P0154, P0157, P0158, P0160,
P1133, P1153, P2A01, P2A04............................................................................................................................. 111
DTC Descriptors................................................................................................................................................. 111
Circuit Description............................................................................................................................................. 111
Heated O2 Sensor.......................................................................................................................................... 111
Conditions for Running the DTC...................................................................................................................... 112
DTC P0131, P0137, P0151 or P0157 ............................................................................................................ 112
DTC P0132, P0138, P0152 or P0158 ............................................................................................................ 112
DTC P0133 or P0153..................................................................................................................................... 112
DTC P0134, P0140, P0154 or P0160 ............................................................................................................ 112
DTC P1133 or P1153..................................................................................................................................... 112
DTC P2A01 or P2A04.................................................................................................................................... 112
Conditions for Setting the DTC ........................................................................................................................ 113
DTC P0131, P0137, P0151 or P0157 ............................................................................................................ 113
DTC P0132, P0138, P0152 or P0158 ............................................................................................................ 113
DTC P0133 or P0153..................................................................................................................................... 113
DTC P0134, P0140, P0154 or P0160 ............................................................................................................ 113
DTC P1133 or P1153..................................................................................................................................... 113
DTC P2A01 or P2A04.................................................................................................................................... 113
Conditions for Clearing the DTC...................................................................................................................... 113
Additional Information....................................................................................................................................... 113
Diagnostic Table for the Heated Oxygen Sensor Reference Circuit DTCs................................................... 114
6.11 DTC P0171, P0172, P0174, P0175 ..................................................................................................................... 116
DTC Descriptors................................................................................................................................................. 116
Circuit Description............................................................................................................................................. 116
Conditions for Running the DTC...................................................................................................................... 116
DTCs P0171, P0172, P0174, and P0175....................................................................................................... 116
Conditions for Setting the DTC ........................................................................................................................ 116
DTCs P0171 and P0174 ................................................................................................................................ 116
DTCs P0172 and P0175 ................................................................................................................................ 116
Conditions for Clearing the DTC...................................................................................................................... 116
Additional Information....................................................................................................................................... 117
Diagnostic Table for the Fuel Trim Reference Circuit DTCs.......................................................................... 117
6.12 DTC P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208.................................................................... 119
DTC Descriptors................................................................................................................................................. 119
Circuit Description............................................................................................................................................. 119
Conditions for Running the DTC...................................................................................................................... 119
Conditions for Setting the DTC ........................................................................................................................ 119
DTC P0201, P0202, P0203, P0204, P0205, P0206, P0207 or P0208 ........................................................... 119
Conditions for Clearing the DTC...................................................................................................................... 119
Additional Information....................................................................................................................................... 119
Test Description................................................................................................................................................. 120
DTC P0201 to P0208, Diagnostic Table............................................................................................................ 120
6.13 DTC P0230.......................................................................................................................................................... 122
DTC Description................................................................................................................................................. 122
Circuit Description............................................................................................................................................. 122
Diagnostic Aids for the Fuel Pump Control Circuit DTCs.............................................................................. 122
Conditions for Running the DTC..................................................................................................................... 122
Conditions for Setting the DTC....................................................................................................................... 122
Conditions for Clearing the DTC..................................................................................................................... 122
Additional Information..................................................................................................................................... 122
Test Descriptions............................................................................................................................................ 122
Diagnostic Table for the Fuel Pump Control Circuit DTCs ............................................................................ 123
6.14 DTC P0300, P1380, P1381.................................................................................................................................. 125
DTC Descriptor................................................................................................................................................... 125
Circuit Description............................................................................................................................................. 125
Conditions for Running the DTCs.................................................................................................................... 125
Conditions for Setting the DTC ........................................................................................................................ 125
Action Taken When the DTC Sets .................................................................................................................... 125
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Conditions for Clearing the MIL/DTC............................................................................................................... 125
Additional Information....................................................................................................................................... 126
DTCs P0300 and P1380 ................................................................................................................................ 126
DTC P1381 .................................................................................................................................................... 126
Test Description................................................................................................................................................. 126
DTC P0300, P1380 and P1381 Diagnostic Table.............................................................................................. 126
6.15 DTC P0315, P0335, P0336 and P0654............................................................................................................... 128
DTC Description................................................................................................................................................. 128
Circuit Description............................................................................................................................................. 128
Conditions for Running the DTCs.................................................................................................................... 128
DTC P0315 .................................................................................................................................................... 128
DTC P0335 .................................................................................................................................................... 128
DTC P0336 .................................................................................................................................................... 128
Conditions for Setting the DTCs....................................................................................................................... 128
DTC P0315 .................................................................................................................................................... 128
DTC P0335 .................................................................................................................................................... 128
DTC P0336 .................................................................................................................................................... 128
Conditions for Clearing the DTCs .................................................................................................................... 129
Additional Information....................................................................................................................................... 129
Diagnostic Table for the CKP Sensor Circuit DTCs........................................................................................ 129
6.16 DTC P0324, P0325, P0326, P0327, P0328, P0330, P0332, P0333.................................................................... 133
DTC Descriptors................................................................................................................................................. 133
Circuit Description............................................................................................................................................. 133
DTC P0324 only............................................................................................................................................. 133
Test One ........................................................................................................................................................ 133
Test Two ........................................................................................................................................................ 133
Test Three...................................................................................................................................................... 133
Conditions for Running the DTC...................................................................................................................... 134
DTC P0324 .................................................................................................................................................... 134
Condition One ................................................................................................................................................ 134
Condition Two ................................................................................................................................................ 134
Condition Three.............................................................................................................................................. 134
DTC P0325 .................................................................................................................................................... 134
DTC P0326 .................................................................................................................................................... 134
DTC P0327 .................................................................................................................................................... 134
DTC P0328 .................................................................................................................................................... 135
DTC P0330 .................................................................................................................................................... 135
DTC P0332 .................................................................................................................................................... 135
DTC P0333 .................................................................................................................................................... 135
Conditions for Setting the DTC ........................................................................................................................ 135
DTC P0324 .................................................................................................................................................... 135
DTC P0325 .................................................................................................................................................... 135
DTC P0326 .................................................................................................................................................... 135
DTC P0327 .................................................................................................................................................... 135
DTC P0328 .................................................................................................................................................... 135
DTC P0330 .................................................................................................................................................... 135
DTC P0332 .................................................................................................................................................... 136
DTC P0333 .................................................................................................................................................... 136
Conditions for Clearing the DTC...................................................................................................................... 136
Additional Information....................................................................................................................................... 136
Test Description................................................................................................................................................. 136
Diagnostic Table for the Knock Sensor and Circuit DTCs............................................................................. 136
6.17 DTC P0340, P0341.............................................................................................................................................. 138
Circuit Description............................................................................................................................................. 138
Conditions for Running the DTCs.................................................................................................................... 138
Conditions for Setting the DTCs....................................................................................................................... 138
DTC P0340 .................................................................................................................................................... 138
DTC P0341 .................................................................................................................................................... 138
Conditions for Clearing the DTCs .................................................................................................................... 138
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Additional Information....................................................................................................................................... 138
Test Description................................................................................................................................................. 138
Diagnostic Table for the CMP Sensor Circuit DTCs ....................................................................................... 139
6.18 DTC P0351, P0352, P0353, P0354, P0355, P0356, P0357, P0358.................................................................... 141
DTC Description................................................................................................................................................. 141
Circuit Description............................................................................................................................................. 141
Conditions for Running the DTCs.................................................................................................................... 141
Conditions for Setting the DTCs....................................................................................................................... 141
Conditions for Clearing the DTCs .................................................................................................................... 141
Additional Information....................................................................................................................................... 141
Test Descriptions............................................................................................................................................... 142
Diagnostic Table for the Ignition Control Circuit DTCs.................................................................................. 142
6.19 DTC P0420 or P0430 .......................................................................................................................................... 144
DTC Descriptors................................................................................................................................................. 144
Circuit Description............................................................................................................................................. 144
Conditions for Running the DTC...................................................................................................................... 144
Conditions for Setting the DTC ........................................................................................................................ 144
Action Taken When the DTC Sets .................................................................................................................... 144
Conditions for Clearing the DTC...................................................................................................................... 145
P0420 or P0430 Diagnostic Table..................................................................................................................... 145
6.20 DTC P0443.......................................................................................................................................................... 146
DTC Description................................................................................................................................................. 146
Circuit Description............................................................................................................................................. 146
Conditions for Running the DTC...................................................................................................................... 146
Conditions for Setting the DTC ........................................................................................................................ 146
Conditions for Clearing the DTC...................................................................................................................... 146
Additional Information....................................................................................................................................... 146
Diagnostic Table for the Evaporative Emission Control System Purge Control Circuit DTCs ................... 146
6.21 DTC P0461, P0462 and P0463........................................................................................................................... 148
DTC Description................................................................................................................................................. 148
Circuit Description............................................................................................................................................. 148
Conditions for Running the DTCs.................................................................................................................... 148
Conditions for Setting the DTCs....................................................................................................................... 148
DTC P0461 .................................................................................................................................................... 148
DTC P0462 and DTC P0463.......................................................................................................................... 148
Conditions for Clearing the DTCs .................................................................................................................... 148
Additional Information....................................................................................................................................... 148
Diagnostic Table for the Fuel Tank Sensor DTCs........................................................................................... 149
6.22 DTC P0480, P0481.............................................................................................................................................. 151
DTC Description................................................................................................................................................. 151
Circuit Description............................................................................................................................................. 151
Conditions for Running the DTCs.................................................................................................................... 151
Condition for Setting the DTCs ........................................................................................................................ 151
Conditions for Clearing DTCs ........................................................................................................................... 151
Additional Information....................................................................................................................................... 151
Diagnostic Table for the Cooling Fan High Speed Relay Circuit DTCs......................................................... 151
6.23 DTC P0502.......................................................................................................................................................... 153
DTC Description................................................................................................................................................. 153
Circuit Description............................................................................................................................................. 153
Conditions for Running the DTC...................................................................................................................... 153
DTC P0502 .................................................................................................................................................... 153
Conditions for Setting the DTC ........................................................................................................................ 153
DTC P0502 .................................................................................................................................................... 153
Conditions for Clearing DTC............................................................................................................................. 153
Additional Information....................................................................................................................................... 153
Diagnostic Table for the Vehicle Speed Sensor Circuit DTCs....................................................................... 154
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6.24 DTC P0506, P0507 P2119................................................................................................................................... 156
DTC Descriptors................................................................................................................................................. 156
Circuit Description............................................................................................................................................. 156
Conditions for Running the DTC...................................................................................................................... 156
DTC P0506 and P0507 .................................................................................................................................. 156
DTC P2119 .................................................................................................................................................... 156
Conditions for Setting the DTC ........................................................................................................................ 157
DTC P0506 .................................................................................................................................................... 157
DTC P0507 .................................................................................................................................................... 157
DTC P2119 .................................................................................................................................................... 157
Conditions for Clearing the DTC...................................................................................................................... 157
Additional Information....................................................................................................................................... 157
Test Description................................................................................................................................................. 157
Diagnostic Table for.P0506, P0507 or P2119................................................................................................... 157
6.25 DTC P0513, P0633, P1629, P1632, P1648, P1677, P1678, P1679.................................................................... 160
DTC Descriptors................................................................................................................................................. 160
Circuit Description............................................................................................................................................. 160
Conditions for Running the DTC...................................................................................................................... 160
Conditions for Setting the DTC ........................................................................................................................ 160
P0513............................................................................................................................................................. 160
P0633............................................................................................................................................................. 160
P1629............................................................................................................................................................. 161
P1632............................................................................................................................................................. 161
P1677............................................................................................................................................................. 161
P1678............................................................................................................................................................. 161
P1679............................................................................................................................................................. 161
Conditions for Clearing the DTC...................................................................................................................... 161
Additional Information....................................................................................................................................... 161
Diagnostic Table for DTCs P0513, P0663, P1629, P1632, P1648, P1677, P1678, P1679............................... 161
6.26 DTC P0522, P0523.............................................................................................................................................. 163
DTC Description................................................................................................................................................. 163
Circuit Description............................................................................................................................................. 163
Conditions for Running the DTCs.................................................................................................................... 163
Conditions for Setting the DTCs....................................................................................................................... 163
Conditions for Clearing the DTCs .................................................................................................................... 163
Additional Information....................................................................................................................................... 163
Test Descriptions............................................................................................................................................... 163
Diagnostic Table for the Engine Oil Pressure Sensor Circuit DTCs ............................................................. 164
6.27 DTC P0532, P0533.............................................................................................................................................. 166
DTC Description................................................................................................................................................. 166
Circuit Description............................................................................................................................................. 166
Conditions for Running the DTC...................................................................................................................... 166
Conditions for Setting the DTC ........................................................................................................................ 166
DTC P0532 .................................................................................................................................................... 166
DTC P0533 .................................................................................................................................................... 166
Conditions for Clearing the DTC...................................................................................................................... 166
Additional Information....................................................................................................................................... 166
Test Description................................................................................................................................................. 167
DTC P0532 and P0533 Diagnostic Table.......................................................................................................... 167
6.28 DTC P0562, P0563.............................................................................................................................................. 169
DTC Descriptors................................................................................................................................................. 169
Circuit Description............................................................................................................................................. 169
Conditions for Running the DTC...................................................................................................................... 169
Conditions for Setting the DTC ........................................................................................................................ 169
DTC P0562 .................................................................................................................................................... 169
DTC P0563 .................................................................................................................................................... 169
Conditions for Clearing the DTC...................................................................................................................... 169
Additional Information....................................................................................................................................... 169
DTC P0562 or P0563 Diagnostic Table............................................................................................................. 170
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6.29 DTC P0575.......................................................................................................................................................... 171
DTC Descriptor................................................................................................................................................... 171
Circuit Description............................................................................................................................................. 171
Conditions for Running the DTC...................................................................................................................... 171
Conditions for Setting the DTC ........................................................................................................................ 171
Conditions for Clearing the DTC...................................................................................................................... 171
Additional Information....................................................................................................................................... 171
Test Description................................................................................................................................................. 171
DTC P0575.......................................................................................................................................................... 171
6.30 DTC P0601, P0602, P0603, P0604, P0606, P0607, P062F, P1621, P1681, P2610 ........................................... 173
DTC Description................................................................................................................................................. 173
Circuit Description............................................................................................................................................. 173
Conditions for Running the DTC...................................................................................................................... 173
DTC P0601 .................................................................................................................................................... 173
DTC P0602,P0603 and P0606....................................................................................................................... 173
DTC P0604 .................................................................................................................................................... 173
DTC P0607 .................................................................................................................................................... 173
DTC P062F .................................................................................................................................................... 173
Conditions for Setting the DTC ........................................................................................................................ 173
DTC P0601 .................................................................................................................................................... 173
DTC P0602 .................................................................................................................................................... 173
DTC P0603 .................................................................................................................................................... 173
DTC P0604 .................................................................................................................................................... 174
DTC P0606 .................................................................................................................................................... 174
DTC P0607 .................................................................................................................................................... 174
DTC P062F .................................................................................................................................................... 174
Conditions for Clearing the DTC...................................................................................................................... 174
Additional Information....................................................................................................................................... 174
DTC P0601, P0602, P0603, P0604, P0606, P0607 and P062F Diagnostic Table ............................................ 174
6.31 DTC P0608.......................................................................................................................................................... 176
DTC Description................................................................................................................................................. 176
Circuit Description............................................................................................................................................. 176
Conditions for Running the DTC...................................................................................................................... 176
Conditions for Setting the DTC ........................................................................................................................ 176
Conditions for Clearing DTCs ........................................................................................................................... 176
Additional Information....................................................................................................................................... 176
Test Descriptions............................................................................................................................................... 176
Diagnostic Table for the Vehicle Speed Output Circuit DTC ......................................................................... 177
6.32 DTC P060D, P1680, P2120, P2122, P2123, P2125, P2127, P2128, P2138 ....................................................... 179
DTC Descriptors................................................................................................................................................. 179
Circuit Description............................................................................................................................................. 179
Conditions for Running the DTC...................................................................................................................... 179
DTC P060D.................................................................................................................................................... 179
DTC P1680 .................................................................................................................................................... 179
DTC P2120, P2122, P2123, P2125, P2127, P2128 and P2138..................................................................... 179
Conditions for Setting the DTC ........................................................................................................................ 180
DTC P060D.................................................................................................................................................... 180
DTC P1680 .................................................................................................................................................... 180
DTC P2120 .................................................................................................................................................... 180
DTC P2122 .................................................................................................................................................... 180
DTC P2123 .................................................................................................................................................... 180
DTC P2125 .................................................................................................................................................... 180
DTC P2127 .................................................................................................................................................... 180
DTC P2128 .................................................................................................................................................... 180
DTC P2138 .................................................................................................................................................... 180
Conditions for Clearing DTC............................................................................................................................. 180
Additional Information....................................................................................................................................... 180
Test Description................................................................................................................................................. 180
DTC P060D, P2120, P2122, P2123, P2125, P2127, P2128, P2138 Diagnostic Table...................................... 181
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–10
Page 6C4-2–10
6.33 DTC P0621, P0622.............................................................................................................................................. 183
DTC Descriptors................................................................................................................................................. 183
Circuit Description............................................................................................................................................. 183
Conditions for Running the DTC...................................................................................................................... 183
DTC P0621 .................................................................................................................................................... 183
DTC P1622 .................................................................................................................................................... 183
Conditions for Setting the DTC ........................................................................................................................ 183
DTC P0621 .................................................................................................................................................... 183
DTC P1622 .................................................................................................................................................... 183
Conditions for Clearing DTC............................................................................................................................. 184
Additional Information....................................................................................................................................... 184
DTC P0621 AND P0622 Diagnostic Table......................................................................................................... 184
6.34 DTC P0641 P0651............................................................................................................................................... 186
DTC Description................................................................................................................................................. 186
Circuit Description............................................................................................................................................. 186
Conditions for Running the DTC...................................................................................................................... 186
Conditions for Setting the DTC ........................................................................................................................ 186
Conditions for Clearing the DTC...................................................................................................................... 186
Additional Information....................................................................................................................................... 186
DTC P0641 Diagnostic Table............................................................................................................................. 186
6.35 DTC P0645.......................................................................................................................................................... 188
DTC Description................................................................................................................................................. 188
Circuit Description............................................................................................................................................. 188
Conditions for Running the DTC...................................................................................................................... 188
Conditions for Setting the DTC ........................................................................................................................ 188
Conditions for Clearing the DTC...................................................................................................................... 188
Additional Information....................................................................................................................................... 188
Diagnostic Table for the A/C Clutch Relay Control Circuit DTC.................................................................... 188
6.36 DTC P0685, P0689, P0690.................................................................................................................................. 190
DTC Descriptors................................................................................................................................................. 190
Circuit Description............................................................................................................................................. 190
Conditions for Running the DTC...................................................................................................................... 190
Conditions for Setting the DTC ........................................................................................................................ 190
Conditions for Clearing the DTC...................................................................................................................... 190
Additional Information....................................................................................................................................... 190
Test Description................................................................................................................................................. 190
DTC P0685, P0686 or P0690 Diagnostic Table ................................................................................................ 191
6.37 DTC P0700.......................................................................................................................................................... 192
DTC Descriptor................................................................................................................................................... 192
Circuit Description............................................................................................................................................. 192
Conditions for Running the DTC...................................................................................................................... 192
Conditions for Setting the DTC ........................................................................................................................ 192
Conditions for Clearing the DTC...................................................................................................................... 192
Additional Information....................................................................................................................................... 192
DTC P0700 Diagnostic Table............................................................................................................................. 192
6.38 DTC P0719, P0724.............................................................................................................................................. 193
DTC Descriptor................................................................................................................................................... 193
Circuit Description............................................................................................................................................. 193
Conditions for Running the DTC...................................................................................................................... 193
DTC P0719 .................................................................................................................................................... 193
DTC P0724 .................................................................................................................................................... 193
Conditions for Setting the DTCs....................................................................................................................... 193
Conditions for Clearing the DTC...................................................................................................................... 193
Additional Information....................................................................................................................................... 193
Test Description................................................................................................................................................. 194
DTC P0016.......................................................................................................................................................... 194
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–11
Page 6C4-2–11
6.39 DTC P0801.......................................................................................................................................................... 196
DTC Description................................................................................................................................................. 196
Circuit Description............................................................................................................................................. 196
Conditions for Running the DTC...................................................................................................................... 196
Conditions for Setting the DTC ........................................................................................................................ 196
Conditions for Clearing DTCs ........................................................................................................................... 196
Additional Information....................................................................................................................................... 196
Diagnostic Table for the Reverse Inhibit Solenoid Control Circuit DTC....................................................... 196
6.40 DTC P0831 and P0833 ....................................................................................................................................... 198
DTC Descriptor................................................................................................................................................... 198
Circuit Description............................................................................................................................................. 198
Conditions for Running the DTC...................................................................................................................... 198
DTC P0831, P0833........................................................................................................................................ 198
Conditions for Setting the DTC ........................................................................................................................ 198
Conditions for Clearing the DTC...................................................................................................................... 198
Additional Information....................................................................................................................................... 198
Test Description................................................................................................................................................. 198
DTC P0831 and P0833 ....................................................................................................................................... 199
6.41 DTC P0851, P0852.............................................................................................................................................. 201
DTC Descriptor................................................................................................................................................... 201
Circuit Description............................................................................................................................................. 201
Conditions for Running the DTC...................................................................................................................... 201
DTC P0851, P0852........................................................................................................................................ 201
Conditions for Setting the DTC ........................................................................................................................ 201
Conditions for Clearing the DTC...................................................................................................................... 201
Additional Information....................................................................................................................................... 201
Test Description................................................................................................................................................. 201
DTC P0851 and P0852 ....................................................................................................................................... 202
6.42 DTC P0856.......................................................................................................................................................... 203
DTC Description................................................................................................................................................. 203
Circuit Description............................................................................................................................................. 203
Diagnostic Table................................................................................................................................................ 203
6.43 DTC P1575.......................................................................................................................................................... 204
Circuit Description............................................................................................................................................. 204
Additional Information....................................................................................................................................... 204
Conditions for Running the DTC...................................................................................................................... 204
Conditions for Setting the DTC ........................................................................................................................ 204
Conditions for Clearing the DTC...................................................................................................................... 204
DTC P1575 Diagnostic Table............................................................................................................................. 204
6.44 DTC P1682.......................................................................................................................................................... 206
DTC Descriptor................................................................................................................................................... 206
Circuit Description............................................................................................................................................. 206
Conditions for Running the DTC...................................................................................................................... 206
Conditions for Setting the DTC ........................................................................................................................ 206
Conditions for Clearing the DTC...................................................................................................................... 206
Action Taken When the DTC Sets .................................................................................................................... 206
Additional Information....................................................................................................................................... 206
DTC P1682.......................................................................................................................................................... 207
6.45 DTC P2544.......................................................................................................................................................... 208
DTC Descriptor................................................................................................................................................... 208
Circuit Description............................................................................................................................................. 208
Conditions for Running the DTC...................................................................................................................... 208
Condition for Setting the DTC .......................................................................................................................... 208
Conditions for Clearing the DTC...................................................................................................................... 208
Action Taken When the DTC Sets .................................................................................................................... 208
Additional Information....................................................................................................................................... 208
DTC P2544.......................................................................................................................................................... 209
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–12
Page 6C4-2–12
6.46 DTC U0073.......................................................................................................................................................... 210
DTC Description................................................................................................................................................. 210
Circuit Description............................................................................................................................................. 210
Conditions for Running the DTC...................................................................................................................... 210
DTC U0073 .................................................................................................................................................... 210
Conditions for Setting the DTC ........................................................................................................................ 210
Conditions for Clearing the DTC...................................................................................................................... 210
Additional Information....................................................................................................................................... 210
Test Description................................................................................................................................................. 210
DTC U0073 Diagnostic Table ............................................................................................................................ 211
6.47 DTC U0101, U0121 ............................................................................................................................................. 212
DTC Description................................................................................................................................................. 212
Circuit Description............................................................................................................................................. 212
Conditions for Running the DTC...................................................................................................................... 212
DTC U0101 .................................................................................................................................................... 212
Conditions for Setting the DTC ........................................................................................................................ 212
Conditions for Clearing the DTC...................................................................................................................... 212
Additional Information....................................................................................................................................... 212
Test Description................................................................................................................................................. 213
DTC P0864 and U0101 Diagnostic Table.......................................................................................................... 213
7 V8 Engine – Tech 2 Functions ..........................................................................................................214
7.1 Introduction........................................................................................................................................................ 214
7.2 Tech 2 Functions ............................................................................................................................................... 215
F0: Diagnostic Trouble Codes........................................................................................................................... 215
F1: Data Display.................................................................................................................................................. 215
Ignition ON: .................................................................................................................................................... 215
Engine Running.............................................................................................................................................. 215
F2: OBD Data ...................................................................................................................................................... 216
F3: Snapshot....................................................................................................................................................... 216
F4: Actuator Test................................................................................................................................................ 216
F5: Additional Functions.................................................................................................................................... 216
F6: Programming................................................................................................................................................ 217
7.3 GEN IV V8 Engine Data Lists ............................................................................................................................ 218
Engine Data........................................................................................................................................................ 218
EVAP Data .......................................................................................................................................................... 220
Fuel Trim Data.................................................................................................................................................... 221
O2 Sensor Data.................................................................................................................................................. 222
TAC Data (Throttle Actuator Control)............................................................................................................... 224
Cooling/HVAC Data............................................................................................................................................ 226
Cruise/Traction Data.......................................................................................................................................... 227
Electrical/Theft Data .......................................................................................................................................... 228
Instrument Data.................................................................................................................................................. 228
ODM Data (Output Driver Module).................................................................................................................... 229
Misfire Data......................................................................................................................................................... 230
7.4 Tech 2 Data Definitions ..................................................................................................................................... 232
7.5 OBD Data............................................................................................................................................................ 237
7.6 Actuator Test...................................................................................................................................................... 238
Fan Relays.......................................................................................................................................................... 238
Fuel Pump Relay Test........................................................................................................................................ 238
Electronic Throttle Control Test....................................................................................................................... 238
A/C Relay Test.................................................................................................................................................... 238
Alternator L Terminal......................................................................................................................................... 238
EVAP Purge Solenoid........................................................................................................................................ 239
Engine Speed Control ....................................................................................................................................... 239
Starter Motor Relay Test.................................................................................................................................... 239
Malfunction Indicator Lamp (MIL) Test............................................................................................................ 239
Fuel Injector Balance......................................................................................................................................... 240
7.7 Programming...................................................................................................................................................... 241
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–13
Page 6C4-2–13
1 General Information
1.1 Diagnostic System Check
The GEN IV V8 Engine Management diagnostic procedures are organised in a logical structure that begins with the Main
Diagnostic Table. The Main Diagnostic Table directs the diagnostic procedure in logical steps necessary to diagnose an
engine driveability fault condition.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–14
Page 6C4-2–14
1.2 Diagnostic Trouble Code Tables
The Main Diagnostic Table directs the diagnostic procedure to the appropriate Diagnostic Trouble Code (DTC) Tables if
there is a DTC currently stored in the ECM.
The diagnostic tables locate a faulty circuit or component through a logic based on the process of elimination. These
diagnostic tables are developed with the following assumptions:
• the vehicle functioned correctly at the time of assembly,
• there are no multiple faults, and
• the problem currently exists
Understanding and the correct use of the diagnostic tables are essential to reduce diagnostic time and to prevent
mis-diagnosis
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–15
Page 6C4-2–15
1.3 Multiple DTCs Fault Condition
Some fault conditions trigger multiple component DTCs even if the fault condition exists only on a single component. If
there are multiple DTCs stored in the ECM, the service technician must view and record all DTCs logged.
The relationship between the logged DTCs can then be analysed to determine the source of the fault condition. Always
begin the diagnostic process with the DTC Table of the fault condition that may trigger other DTCs to set.
The following fault conditions may trigger multiple DTCs:
• A fault in the serial data communication circuit.
• A system voltage that is too low may cause incorrect engine management system operation or engine management
component malfunction.
• A system voltage that is too high may damage the ECM and/or other engine management components.
• Fault condition in the ECM Read Only Memory (ROM) or Random Access Memory (RAM).
• Fault condition in the ECM internal circuitry or programming.
• Improperly connected sensor or component wiring connector.
• An electrical fault condition in the following shared ECM electrical circuits trigger DTCs on components or sensors
that share in the faulty shared circuit. Test the electrical circuit of the appropriate sensors or components to isolate
the fault condition. Refer to 2 Wiring Diagrams and Connector Charts.
• 5 Volts Reference Circuit,
• Low Reference Circuit, or
• Ignition Control Voltage Circuit.
If there are no obvious faults to begin a multiple DTC fault condition diagnostic procedure, diagnose the DTCs in the
following order unless directed otherwise:
1 Always start with the lowest numbered Component Level DTCs such as:
• sensor DTCs,
• solenoid DTCs, or
• relay DTCs.
2 Then follow with System Level DTCs such as:
• fuel trim DTCs
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–16
Page 6C4-2–16
1.4 Symptoms Diagnostics
The Main Diagnostic Table directs the service technician to the Symptoms Diagnostics if the following conditions exist.
• An ECM fault condition exists.
• There is no Current Diagnostic Trouble Code presently stored in the ECM.
• All the Tech 2 engine data parameters are within normal operating range.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–17
Page 6C4-2–17
1.5 Diagnostic Trouble Codes
The ECM constantly performs self-diagnostic tests on the engine management system. When the ECM detects a fault
condition in the engine operating parameters, the ECM sets a DTC that represents the fault condition. The following are
the types of DTCs programmed in the ECM. In addition, DTCs are classified as either Current or History DTC.
• Type A – Emission Related DTCs
• Type B – Emission Related DTCs
• Type C – Non-Emission Related DTCs
Depending on the type of DTC set, the ECM may request the instrument cluster to activate the Malfunction Indicator
Lamp (MIL) warning in the instrument cluster to warn the driver that there is a fault in the Engine Management System.
Refer to Section 12C Instrumentation for further information on the MIL icon
Type A – Emission Related DTCs
The ECM takes the following action when a Type A DTC runs and fails:
• Sets a current Type A DTC that represents the fault condition.
• The ECM activates the MIL in the instrument cluster.
• The ECM records the operating condition at the time the diagnostic fails and stores this information in the Freeze
Frame / Failure Record.
Type B – Emission Related DTCs
The ECM takes the following action when a Type B DTC runs and fails:
• On the first time a Type B DTC fails, the ECM takes the following actions:
• Sets a current Type B DTC that represents the fault condition.
• Records the operating conditions at the time the fault sets and stores this information in the Failure Records.
• On the second consecutive ignition cycle that a Type B DTC fails, the ECM takes the following actions:
• The ECM activates the MIL in the instrument cluster.
• The ECM records the operating condition at the time the diagnostic fails and stores this information in the
Freeze Frame/ Failure Record.
Conditions for Clearing Type A or Type B DTCs
• The current DTC clears when there is no fault condition in the current ECM self-diagnostics.
• Type A or Type B History DTC clears when there is no fault condition after 40 consecutive warm-up cycles.
• Use of Tech 2 to clear the DTC
If there are no DTCs logged after three or four consecutive ignition cycles, the ECM deactivates the MIL in the instrument
cluster.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–18
Page 6C4-2–18
Type C – Non-Emission Related DTCs
The ECM takes the following action when a Type A DTC runs and fails:
• Sets a current Type C DTC that represents the fault condition.
• The ECM records the operating conditions at the time the DTC is logged and stores this information in the Failure
Record.
• The ECM may activate a Service Vehicle Soon message in the MFD.
Condition for Clearing the Type C DTCs
• The current DTC clears when there is no fault condition in the current ECM self-diagnostics.
• Type C History DTC clears when there is no fault condition after 40 consecutive warm-up cycles.
• Use of Tech 2 to clear the DTC
Current DTCs
A DTC is a Current DTC if the fault condition that triggers that DTC is present during the current ECM self-diagnostics.
History DTCs
A DTC is a History DTC if the fault condition that triggers that DTC is not present during the current ECM self-
diagnostics.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–19
Page 6C4-2–19
2 Wiring Diagrams and Connector
Charts
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–20
Page 6C4-2–20
2.1 Wiring Diagrams
Figure 6C4-2 – 1
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–21
Page 6C4-2–21
Figure 6C4-2 – 2
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–22
Page 6C4-2–22
Figure 6C4-2 – 3
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–23
Page 6C4-2–23
Figure 6C4-2 – 4
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–24
Page 6C4-2–24
Figure 6C4-2 – 5
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–25
Page 6C4-2–25
Figure 6C4-2 – 6
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–26
Page 6C4-2–26
Figure 6C4-2 – 7
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–27
Page 6C4-2–27
2.2 Connector Chart
Figure 6C4-2 – 8
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–28
Page 6C4-2–28
Figure 6C4-2 – 9
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–29
Page 6C4-2–29
3 Diagnostic Starting Point
3.1 Basic Requirements
Basic Knowledge Required
A lack of basic understanding regarding
electronics, electrical wiring circuits and use
of electrical circuit testing tools when
performing the engine management system
diagnostic procedures could result in
incorrect diagnostic results or damage to
ECM System components.
A general understanding of the following is required to perform the diagnostic procedures detailed in this Section. Refer
to Section 12P Wiring Diagrams and to Basic Tools Required.
• Basic electronics
• Electrical wiring circuits
• Electrical circuits testing
• Correct use of the basic ECM System diagnostic tools
In addition, a general understanding of the GEN IV V8 Engine Management System is essential to prevent misdiagnosis
and component damage, refer to Section 6C4–1 Engine Management GEN IV V8 – General Information
Basic Tools Required
• Use of incorrect electrical circuit
diagnostic tools when performing the
engine management diagnostic
procedures could result in incorrect
diagnostic results or damage to engine
management system components.
• When tests are required on connector
terminals, use the adapters in the
connector adapter kit KM–609 to prevent
damage to the terminals.
The following electrical circuit testing tools are required to perform the diagnostic procedures detailed in this section.
• Tech 2, refer to Section 0C Tech 2
• Test light, refer to Section 12P Wiring Diagrams
• Digital multimeter with 10 mega-ohms impedance, refer to Section 12P Wiring Diagrams
• Connector adapter kit, special tool No. KM–609.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–30
Page 6C4-2–30
3.2 Diagnostic Precautions
The following precautions must be observed when performing engine diagnostic procedures, otherwise incorrect
diagnostic results or damage to ECM System components will occur:
• Disconnection of the battery affects certain vehicle electronic systems. Refer to the battery disconnection procedure
in Section 00 Warnings, Cautions and Notes before disconnecting the battery.
• Disconnect the battery negative lead when performing the following procedures:
• disconnecting the ECM connectors
• charging the battery
• Disconnect the battery terminal lead and the ECM connectors before attempting any electric arc welding on the
vehicle.
• Do not start the engine if the battery terminal is not properly secured to the battery.
• Do not disconnect or reconnect the following while the ignition is switched On or when the engine is running:
• any engine management system component electrical wiring connector
• any battery terminal leads
• Ensure that the correct procedure for disconnecting and connecting engine management system electrical wiring
connectors is always followed. For information on the correct procedure for disconnecting and connecting specific
wiring connectors, refer to Section 6C4-3 Engine Management GEN IV V8 – Service Operations.
• Ensure that all wiring harness connectors are fitted correctly.
• When steam or pressure cleaning engines, do not direct the cleaning nozzle at engine management system
components.
• Do not clear any DTCs unless instructed.
• The fault must be present when using the Diagnostic Trouble Code (DTC) Diagnostic Tables. Otherwise,
misdiagnosis or replacement of good parts may occur.
• Do not touch the ECM connector pins or soldered components on the ECM circuit board to prevent ECM
Electrostatic Discharge damage. Refer to Section 12P Wiring Diagrams for information on Electrostatic Discharge.
• Use only the test equipment specified in the diagnostic tables as other test equipment may give incorrect results or
damage good components.
• The ECM is designed to withstand normal current draw associated with vehicle operations. However, the following
fault conditions or incorrect test procedure may overload the ECM internal circuit and damage the ECM:
• A short to voltage fault condition in any of the ECM low reference circuits may cause internal ECM and/or
sensor damage. Therefore, any short to voltage fault condition in the ECM low reference circuits must be
rectified before replacing a faulty component.
• A short to ground fault condition in any of the ECM 5 volts reference circuits may cause internal ECM and/or
sensor damage. Therefore, any short to ground fault condition in the ECM 5 volt reference circuits must be
rectified before replacing a faulty component.
• When using a test light to test an electrical circuit, do not use any of the ECM low reference circuits or 5 volts
reference circuits as a reference point. Otherwise, excessive current draw from the test light may damage the
ECM.
• Disregard DTCs that set while performing the following diagnostic Steps:
• using the Tech 2 output control function, or
• disconnecting an engine management system sensor connector then switching on the ignition.
• After completing the required diagnostics and service operations, road test the vehicle to ensure correct engine
management system operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–31
Page 6C4-2–31
3.3 Preliminary Checks
The Preliminary Checks are a set of visual and physical checks or inspections that may quickly identify an engine
management system fault condition.
• Refer to the appropriate Service Techlines for relevant information regarding the fault condition.
• Ensure that the battery is fully charged.
• Inspect the battery connections for corrosion or a loose terminal.
• Ensure that all engine management system related fuses are serviceable.
• Inspect for incorrect aftermarket theft deterrent devices, lights or mobile phone installation.
• Ensure that there is no speaker magnet positioned too close to any electronic module that contains relays.
• Inspect the engine wiring harness for proper connections, pinches or cuts.
• Ensure that all Engine management related electrical wiring connectors are fitted correctly.
• Inspect the ECM ground connections for corrosion, loose terminal or incorrect position.
• Ensure that the resistance between the ECM housing and the battery negat ive cable is less than 0.5 ohms.
• Check the ECM bracket fasteners for correct torque value.
• Check all engine management related components for correct installation.
• Inspect the vacuum hoses for splits, kinks, oil contamination and proper connections, Refer to the Vehicle Emission
Control Information Label. Check the hoses thoroughly for any type of leak or restriction.
• Inspect the air intake ducts for being collapsed, split or for having damaged areas.
• Inspect for air leaks at the throttle body mounting area, Mass Air Flow (MAF) sensor, intake manifold and intake
manifold sealing surfaces.
• Check for wiring harness routing that may be positioned too close to a high voltage or high current device such as
the following:
• secondary ignition components, and
• motors and generators.
NOTE
High voltage or high current devices may induce
electrical noise on a circuit, which can interfere
with normal circuit operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–32
Page 6C4-2–32
3.4 Diagnostic System Check
Step Action Yes No
1 Have you read the Basic Requirements?
Go to Step 2
Refer to
3.1 Basic
Requirements
2 Have you read the Diagnostic Precautions?
Go to Step 3
Refer to
3.2 Diagnostic
Precautions
3 Have you performed the Preliminary Checks?
Go to Step 4
Refer to
3.3 Preliminary
Checks
4 1 Switch off the ignition.
2 Connect Tech 2 to the Diagnostic Link Connector (DLC).
3 Switch on the ignition with the engine not running.
4 Push the Tech 2 power button.
Does Tech 2 screen illuminate and display Tech 2? Go to Step 5 Refer to 7.2 Tech 2
Functions
5 Using Tech 2, attempt to communicate with the following control
modules:
• Engine Control Module,
• Body Control Module,
• Powertrain Interface Module,
• Instrument Cluster,
• ABS-TCS ECU,
• HVAC Control Module,
• Transmission Control Module
Did any of the control modules fail to communicate?
Refer to 6E4
Powertrain Interface
Module – GEN IV
V8 Go to Step 6
6 Using Tech 2, view and record all DTCs set in the ECM.
Does Tech 2 display any DTC? Go to Step 7 Refer to 6.1 DTC list
7 Does Tech 2 display multiple DTCs?
Go to Step 8
Go to the DTC
Table of the DTC
displayed, refer to
1.3 Multiple DTCs
Fault Condition
8 Does Tech 2 display any Serial Data Communication DTC? Refer to the
appropriate Serial
Data
Communication
DTC Table Go to Step 9
9 Does Tech 2 display any Immobiliser Signal DTC? Refer to 6
Diagnostic Trouble
Code Tables Go to Step 10
10 Refer to the DTC Table of the fault condition that is most likely to
trigger multiple DTCs. Refer to 1.3 Multiple DTCs Fault Condition for
information on multiple DTCs fault condition. – –
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–33
Page 6C4-2–33
4 Symptom Diagnostics
4.1 Symptom Diagnosis Table
Step Action Yes No
1 Was the Main Diagnostic System Check performed? Go to Step 2 Refer to
3.4 Diagnostic
System Check
2 Is the fault intermittent? Refer to
4.2 Intermittent
Fault Condition
Go to Step 3
3 Does the engine backfire? Refer to 4.3 Back
fire Go to Step 4
4 Does the engine crank but not run? Refer to 4.4 Cranks
but does not run Go to Step 5
5 Does the engine cut-out or miss? Refer to 4.5 Cuts
out – misses Go to Step 6
6 Is there a detonation or spark knock noise coming from
the engine? Refer to 4.6
Detonation – Spark
Knock
Go to Step 7
7 Is there an engine dieseling or run-on condition? Refer to 4.7
Dieseling - Running
On.
Go to Step 8
8 Is there an engine hard starting condition? Refer to 4.8 Hard
Start Go to Step 9
9 Is there an engine hesitation, sag or stumble condition? Refer to 4.9
Hesitation, Sag
Stumble
Go to Step 10
10
Does the engine suffer from lack of power, sluggishness
or sponginess? Refer to 4.10. Lack
of Power,
Sluggishness
Sponginess
Go to Step 11
11 Does the engine suffer from poor fuel economy? Refer to 4.11 Poor
Fuel Economy Go to Step 12
12
Does the engine suffer from rough, unstable or incorrect
idle and engine stalling? Refer to 4.12
Rough, Unstable or
Incorrect Idle and
Engine Stalling.
Go to Step 13
13 Does the engine surge or chuggle? Refer to 4.13
Surges / Chuggles Go to Step 14
14 Does the fuel pump operate? Refer to 4.14 Fuel
Pump Not Operating Go to Step 15
15 Does the fuel pump operate continuously? Refer to 4.15 Fuel
Pump Continuously
Operates –
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–34
Page 6C4-2–34
4.2 Intermittent Fault Conditions
Description
A fault condition is intermittent if one of the following conditions exists:
• The fault condition is not always present.
• The fault condition cannot be presently duplicated.
• There is no Current DTC but a History DTC is stored.
Diagnostic Table
Checks Actions
Preliminary • Perform the Preliminary Checks. Refer to 3.3 Preliminary Checks.
• Gather information from the customer regarding the conditions that trigger the
intermittent fault such as:
• At what engine or ambient temperature range does the fault occur?
• Does the fault occur when operating aftermarket electrical equipment inside
the vehicle?
• Does the fault occur on rough roads or in wet road conditions?
• If the intermittent fault is a start and then stall condition, check for DTCs relating to
the Theft Deterrent Device. Refer to 12J Body Control Module.
Tech 2 tests The following are lists of Tech 2 diagnostic tests that may be used to diagnose
intermittent faults:
• Wriggle test the suspected wiring harness and connectors while observing the
Tech 2 operating parameters. If the Tech 2 read-out fluctuates during this
procedure, check the tested wiring harness circuit for a loose connection.
• Observe the Freeze Frame / Failure Records for the suspected history DTC and
then operate the vehicle in the conditions that triggers the intermittent fault while
an assistant observes the suspected Tech 2 operating parameter data.
• Capture and store data in the Snapshot mode when the fault occurs. The stored
data may be played back at a slower rate to aid in diagnostics. Refer to the
Tech 2 User Instructions for more information on the Snapshot function.
• Compare the engine operating parameters of the engine being diagnosed to the
engine operating parameters of a known good engine.
Malfunction Indicator Lamp The following condition may cause an intermittent Malfunction Indicator Lamp fault with
no DTC listed.
• Electromagnetic Interference (EMI) caused by a faulty relay, ECM controlled
solenoid, switch or other external source.
• Incorrect installation of aftermarket electrical equipment such as the following:
• Mobile phones
• Theft deterrent alarms
• Lights
• Radio equipment
• ECM grounds are unsatisfactory.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–35
Page 6C4-2–35
Checks Actions
Temperature Related Temperature related intermittent fault condition occurs only when the engine or ambient
temperature is hot or only when it is cold.
• If the intermittent fault is heat related, review the Tech 2 data in relationship to the
following:
• High ambient temperature.
• Underhood/engine generated heat.
• Circuit generated heat due to a poor electrical connection or high electrical
load.
• Higher than normal load conditions (towing, etc.).
• If the intermittent fault is related to cold ambient or engine temperature, review the
Tech 2 data in relationship to the following:
• Low ambient temperature.
• The fault condition that occurs only on a cold start situation.
Additional Tests • Incorrect installation of aftermarket electrical equipment such as the following:
• Mobile phones
• Theft deterrent alarms
• Lights
• Radio equipment
• Electromagnetic Interference (EMI) caused by a faulty relay, ECM controlled
solenoid or switch. The fault is triggered when the relay or solenoid is activated.
• Test the A/C compressor clutch and some relays that contain a clamping diode or
resistor for an open circuit.
• Test the generator for a faulty rectifier bridge that may allow the A/C noise into the
ECM electrical circuit.
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–36
Page 6C4-2–36
4.3 Backfire
Description
The air/fuel mixture in the intake manifold or in the exhaust system ignites which produces a loud popping noise
Checks Actions
Preliminary Perform the Preliminary Checks. Refer to 3.3 Preliminary Checks.
Sensor/System • Check the air intake system and crankcase for air leaks.
• Check the PCV System for correct operation. Refer to 6A4 Engine Mechanical –
GEN IV V8.
• Use Tech 2 to monitor the knock sensor system for excessive spark retard activity.
Check for items that cause spark retard activity.
Fuel System • Check the fuel system for the following fault conditions. Refer to 8A1 Fuel System.
• restricted fuel filter,
• incorrect fuel pressure, and
• contaminated fuel.
• Check the operation of the fuel injectors. Refer to 6C4-3 Engine Management
GEN IV V8 – Service Operations.
• Perform the fuel injector balance test. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
• Check the items that can cause an engine to run lean.
• Check the items that cause an engine to run rich.
Ignition System • Check for an intermittent ignition circuit malfunction. Refer to 4.2 Intermittent
Fault Conditions.
• Inspect for moisture or corrosion around the spark plug/ignition coil area.
• Test the ignition coil voltage output. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
• Remove and inspect the spark plugs. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
NOTE
If the spark plugs are fouled, determine the cause of the fouling before
replacing the spark plugs. Refer to 6C4-3 Engine Management GEN IV V8 –
Service Operations.
• Check for loose ignition coil ground circuit.
Engine Cooling System Check the engine for over-heating, refer to 6B4 Engine Cooling – GEN IV V8.
Engine Mechanical Check for the following engine fault conditions. Refer to 6A4 Engine Mechanical –
GEN IV V8.
• low compression, and
• worn valve train components.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–37
Page 6C4-2–37
Checks Actions
Additional Checks • Check the exhaust system for possible restrictions. Refer to 8B Exhaust System.
• Electromagnetic Interference (EMI) on the Crankshaft Position (CKP) sensor can
cause an engine misfire condition.
Using Tech 2, monitor the engine speed parameter. A sudden increase in the
engine speed parameters without moving the throttle position indicates that an
Electromagnetic Interference fault may be present.
Wiring harness routing which may be positioned very close to a high voltage or
high current device such as the following may induce EMI:
• secondary ignition components, or
• motors and generators.
Dirty starter motor commutator or brushes can mask the crankshaft position
sensor signal.
• Check the Torque Converter Clutch (TCC) operation. A TCC that applies too soon
can cause engine detonation, which will trigger spark retard activity. Refer to 7D1
Automatic Transmission – 4L65E – General Information.
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–38
Page 6C4-2–38
4.4 Cranks but does not run
Definition
The engine cranks normally but does not start
Checks Actions
Preliminary • Perform the Preliminary Checks. Refer to 3.3 Preliminary Checks.
• Check the Theft Deterrent System for correct operation. Refer to
12J Body Control Module.
Sensor/System • Check the Engine Coolant Temperature (ECT) sensor for an incorrect value.
Compare the Engine Coolant Temperature against the Intake Air Temperature
(IAT) on a cold engine. The ECT and IAT sensor values should be within ± 3°C of
each other. Refer to 6C4-3 Engine Management GEN IV V8 – Service Operations
for details of the Temperature vs. Resistance Table.
• Check the Mass Air Flow (MAF) sensor installation. Incorrect installation of the
MAF sensor may cause hard start condition. Refer to 6C4-3 Engine Management
GEN IV V8 – Service Operations.
• Check for dirty starter motor commutator or brushes that can mask the crankshaft
position sensor signal.
Fuel System • Check the fuel system for the following fault conditions. Refer to 8A1 Fuel System.
• restricted fuel filter,
• incorrect fuel pressure,
• contaminated fuel, and
• incorrect fuel pump relay operation.
• Check the operation of the fuel injectors. Refer to 6C4-3 Engine Management
GEN IV V8 – Service Operations.
Ignition System • Inspect for moisture or corrosion around the spark plug, ignition coil, and spark
plug lead area.
• Test the ignition coil voltage output. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
• Test the spark plug leads. Refer to 6C4-3 Engine Management GEN IV V8 –
Service Operations.
• Remove and inspect the spark plugs. Refer to 6C4-3 Engine Management
GEN IV V8 – Service Operations.
NOTE
If the spark plugs are fouled, determine the cause of the fouling before
replacing the spark plugs. Refer to 6C4-3 Engine Management GEN IV V8 –
Service Operations.
• Check for loose ignition coil ground circuit.
Engine Mechanical • Check for excessive oil in combustion chamber. Refer to 6A4 Engine Mechanical –
GEN IV V8.
• Check for the following engine fault conditions. Refer to 6A4 Engine Mechanical –
GEN IV V8.
• low compression, and
• worn valve train components.
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–39
Page 6C4-2–39
4.5 Cuts Out, Misses
Description
Steady pulsation or jerking that is usually more severe as the engine load increases. This condition is not normally felt
above 1500 RPM or 48 km/h. The exhaust has a steady spitting sound at idle or low speed.
Checks Actions
Preliminary • Perform the Preliminary Checks. Refer to 3.3 Preliminary Checks.
• Check the air filter element and intake air ducts for blockages.
Sensor/System • Using Tech 2, check the Heated Oxygen Sensor (Heated O2 Sensors) operating
parameters. The Heated Oxygen Sensors (Heated O2 Sensors) should respond
quickly to different throttle positions.
• Use Tech 2 to monitor the knock sensor system for excessive spark retard activity.
Check for items that cause spark retard activity. Refer to Knock Sensor DTCs.
Fuel System • Check the fuel system for the following fault conditions. Refer to 8A1 Fuel System.
• restricted fuel filter,
• incorrect fuel pressure, and
• contaminated fuel.
• Check the operation of the fuel injectors. Refer to 6C4-3 Engine Management
GEN IV V8 – Service Operations.
• Perform the fuel injector balance test. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
• Check for fault conditions that cause an engine to run rich or to run lean.
Ignition System • Inspect for moisture or corrosion around the spark plug/ignition coil area.
• Test the ignition coil voltage output. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
• Remove and inspect the spark plugs. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
NOTE
If the spark plugs are fouled, determine the cause of the fouling before
replacing the spark plugs. Refer to 6C4-3 Engine Management GEN IV V8 –
Service Operations.
• Check for loose ignition coil grounds.
Engine Mechanical Check for the following engine fault conditions. Refer to 6A4 Engine Mechanical –
GEN IV V8.
• low compression,
• worn valve train components, and
• vacuum leaks.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–40
Page 6C4-2–40
Checks Actions
Additional Checks • Check the exhaust system for possible restrictions. Refer to 8B Exhaust System.
• Check all vacuum hoses and seals for splits, restrictions, and improper
connection.
• Electromagnetic Interference (EMI) on the Crankshaft Position (CKP) sensor can
cause an engine misfire condition.
Using Tech 2, monitor the engine speed parameter. A sudden increase in the
engine speed parameters without moving the throttle position indicates that an
Electromagnetic Interference fault may be present.
• Wiring harness routing which may be positioned very close to a high voltage or
high current device such as the following may induce EMI:
• secondary ignition components, or
• motors and generators.
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–41
Page 6C4-2–41
4.6 Detonation/Spark Knock
Description
The engine produces sharp rapid metallic knocks that are more audible during acceleration.
Checks Actions
Preliminary Perform the Preliminary Checks. Refer to 3.3 Preliminary Checks.
Sensor System Use Tech 2 to monitor the knock sensor system.
Fuel System • Check the fuel system for the following fault conditions. Refer to 8A1 Fuel System.
• restricted fuel filter,
• incorrect fuel pressure, and
• contaminated fuel.
• Check the operation of the fuel injectors. Refer to 6C4-3 Engine Management
GEN IV V8 – Service Operations.
• Perform the fuel injector balance test. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
• Ensure that the fuel tank is filled with petrol that has a minimum octane reading of
92.
• Check for fault conditions that can cause an engine to run lean. Refer to DTCs that
relate to fuel trim.
Ignition System • Check the spark plugs for proper heat range. Refer to 6C4-3 Engine Management
GEN IV V8 – Service Operations.
Engine Mechanical • Check the combustion chambers for excessive carbon build-up. Refer to 6A4
Engine Mechanical – GEN IV V8.
• Check the camshaft timing. Refer to 6A4 Engine Mechanical – GEN IV V8.
Additional Checks • Check the Torque Converter Clutch (TCC) operation. The TCC applying too soon
can cause the engine to spark knock. Refer to 7D2 Automatic Transmission –
4L65E – Hydraulic and Mechanical Diagnosis.
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–42
Page 6C4-2–42
4.7 Dieseling, Running on
Description
The engine continues to run after the ignition is switched Off but runs very roughly and then stalls
Checks Actions
Preliminary Perform the Preliminary Checks. Refer to 3.3 Preliminary Checks.
Fuel System • Inspect the injectors for leaking condition. Refer to 6C4-3 Engine Management
GEN IV V8 – Service Operations.
Engine Cooling System • Check for engine overheating. Refer to 6B4 Engine Cooling – GEN IV V8.
• Check the engine thermostat for proper operation and correct heat range. Refer to
6B4 Engine Cooling – GEN IV V8.
Engine Mechanical • Check for build up of carbon deposit in the combustion chamber, which may cause
hot spots and increased compression ratio. Refer to 6A4 Engine Mechanical –
GEN IV V8.
• Using Tech 2, check for incorrect engine idle speed.
Additional • If the engine continues to run after the ignition is switched Off but the engine runs
normally, check the following:
• ignition switch operation,
• voltage feedback from alternator L terminal to ignition switch, and
• sticking ignition control relay.
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–43
Page 6C4-2–43
4.8 Hard Start
Definition
The engine cranks normally but takes more time to start than usual. As soon as the engine runs, the engine may stall
immediately
Checks Actions
Preliminary • Perform the Preliminary Checks. Refer to 3.3 Preliminary Checks.
• Check the Theft Deterrent System for correct operation. Refer to 12J Body Control
Module.
Sensor/System • Check the Engine Coolant Temperature (ECT) sensor for an incorrect value.
Compare the Engine Coolant Temperature against the Intake Air Temperature
(IAT) on a cold engine. The ECT and IAT sensor values should be within ± 3°C of
each other. Refer to 6C4-3 Engine Management GEN IV V8 – Service Operations
for details of the Temperature vs. Resistance Table.
• Check the Mass Air Flow (MAF) sensor installation. Incorrect installation of the
MAF sensor may cause hard start condition. Refer to 6C4-3 Engine Management
GEN IV V8 – Service Operations.
• Test the resistance of the Crankshaft Position (CKP) sensor. The CKP sensor
resistance must be within 700 – 1,200 ohms at all temperatures.
• Check for dirty starter motor commutator or brushes that can mask the crankshaft
position sensor signal.
Fuel System • Check the fuel system for the following fault conditions. Refer to 8A1 Fuel System.
• restricted fuel filter,
• incorrect fuel pressure, and
• contaminated fuel.
• Check the operation of the fuel injectors. Refer to 6C4-3 Engine Management
GEN IV V8 – Service Operations.
Ignition System • Inspect for moisture or corrosion around the spark plug/ignition coil area.
• Test the ignition coil voltage output. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
• Remove and inspect the spark plugs. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
NOTE
• If the spark plugs are fouled, determine the cause of the fouling before replacing
the spark plugs. Refer to 6C4-3 Engine Management GEN IV V8 – Service
Operations.
• Check for loose ignition coil ground circuit.
Engine Mechanical • Check for excessive oil in combustion chamber. Refer to 6A4 Engine Mechanical –
GEN IV V8.
• Check for the following engine fault conditions. Refer to 6A4 Engine Mechanical –
GEN IV V8.
• low compression, and
• worn valve train components.
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–44
Page 6C4-2–44
4.9 Hesitation, Sag and Stumble
Description
Momentary lack of response or hesitation as the accelerator is depressed. This condition is usually more severe when
first trying to make the vehicle move from a standing start but can occur at any vehicle speed
Checks Actions
Preliminary • Perform the Preliminary Checks. Refer to 3.3 Preliminary Checks.
• Check the air filter element and intake air ducts for blockages.
Sensor/System • Using Tech 2, check the Heated Oxygen Sensor (Heated O2 Sensors) operating
parameters. The Heated Oxygen Sensors (Heated O2 Sensors) should respond
quickly to different throttle positions.
• Inspect the Accelerator Pedal Position (APP) sensor harness connector for correct
connection. Poor connection of this connector will not set a DTC.
Fuel System • Check the fuel system for the following fault conditions. Refer to
8A1 Fuel System.
• restricted fuel filter,
• incorrect fuel pressure, and
• contaminated fuel.
• Check the operation of the fuel injectors. Refer to 8A1 Fuel System.
• Perform the fuel injector balance test. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
• Check for fault conditions that cause an engine to run rich or to run lean.
Ignition System • Inspect for moisture or corrosion around the spark plug/ignition coil area.
• Test the ignition coil voltage output. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
• Remove and inspect the spark plugs. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
NOTE
If the spark plugs are fouled, determine the cause of the fouling before
replacing the spark plugs. Refer to 6C4-3 Engine Management GEN IV V8 –
Service Operations.
• Check for loose ignition coil ground circuit.
Engine Cooling System Check the engine thermostat for correct operation and heat range. Refer to 6B4 Engine
Cooling – GEN IV V8.
Additional Checks • If fitted, check for the correct operation of the intake manifold runner control
system. Refer to 6C4-3 Engine Management GEN IV V8 – Service Operations.
• Check the generator output voltage. Refer to 6D4-1 Charging System –
GEN IV V8.
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–45
Page 6C4-2–45
4.10 Lack of Power, Sluggishness or
Sponginess
Description
The engine delivers less than normal power. There is little or no increase in vehicle speed when the accelerator pedal is
partially depressed
Checks Actions
Preliminary • Perform the Preliminary Checks. Refer to 3.3 Preliminary Checks.
• Check the air filter element and intake air ducts for blockages.
Sensor/System • Use Tech 2 to monitor the knock sensor system for excessive spark retard activity.
Check for items that cause spark retard activity.
• Inspect the Accelerator Pedal Position (APP) sensor harness connector for correct
connection. Poor connection of this connector will not set a DTC.
Fuel System • Check the fuel system for the following fault conditions. Refer to 8A1 Fuel System.
• restricted fuel filter,
• incorrect fuel pressure, and
• contaminated fuel.
• Check the operation of the fuel injectors. Refer to 6C4-3 Engine Management
GEN IV V8 – Service Operations.
• Perform the fuel injector balance test. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
• Check for fault conditions that can cause the engine to run rich or run lean.
Ignition System • Inspect for moisture or corrosion around the spark plug/ignition coil area.
• Test the ignition coil voltage output. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
• Remove and inspect the spark plugs. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
NOTE
If the spark plugs are fouled, determine the cause of the fouling before
replacing the spark plugs. Refer to 6C4-3 Engine Management GEN IV V8 –
Service Operations.
• Check for loose ignition coil ground circuit.
Engine Mechanical • Check for the following engine mechanical fault condition. Refer to 6A4 Engine
Mechanical – GEN IV V8.
• low engine compression, and
• worn valve train components.
Additional Checks • Check the exhaust system for possible restrictions. Refer to 8B Exhaust System.
• Test for other TCM related faults that may cause the transmission to operate in the
default mode.
• Check for transmission mechanical faults that may produce similar symptoms such
as slipping clutch.
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–46
Page 6C4-2–46
4.11 Poor Fuel Economy
Description
As confirmed by an actual road test, the fuel economy as compared to the previous fuel consumption of the same vehicle
is noticeably lower.
Checks Actions
Preliminary • Perform the Preliminary Checks. Refer to 3.3 Preliminary Checks.
• Check the air filter element and intake air ducts for blockages.
• Check for correct tyre pressure. Refer to 10 Wheels and Tyres.
• Check that the recent driving conditions are the same compared to the previous
when the fuel consumption is normal. The following are list of driving conditions
that may affect fuel consumption:
• vehicle load,
• acceleration rate,
• A/C or other electrical equipment use, and
• vehicle used for towing.
Sensor/System • Check the air intake system and crankcase for air leaks.
• Check the PCV System for correct operation. Refer to 6A4 Engine Mechanical –
GEN IV V8.
• Check for the correct calibration of the speedometer. Refer to
12C Instrumentation.
• Use Tech 2 to monitor the knock sensor system for excessive spark retard activity.
Check for items that cause spark retard activity.
• Using Tech 2, check the Heated Oxygen Sensor (Heated O2 Sensor) operating
parameters. The Heated Oxygen Sensors (Heated O2 Sensors) should respond
quickly to different throttle positions.
Fuel System • Check the fuel system for the following fault conditions. Refer to 8A1 Fuel System.
• restricted fuel filter,
• incorrect fuel pressure, and
• contaminated fuel.
• Check the operation of the fuel injectors. Refer to 6C4-3 Engine Management
GEN IV V8 – Service Operations.
• Perform the fuel injector balance test. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
• Check the items that cause an engine to run rich.
• Check for foreign material accumulation in the throttle bore, carbon build-up on the
throttle valve or on the throttle shaft.
• Check the throttle body for tampering.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–47
Page 6C4-2–47
Checks Actions
Ignition System • Inspect for moisture or corrosion around the spark plug/ignition coil area.
• Test the ignition coil voltage output. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
• Remove and inspect the spark plugs. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
NOTE
If the spark plugs are fouled, determine the cause of the fouling before
replacing the spark plugs. Refer to 6C4-3 Engine Management GEN IV V8 –
Service Operations.
• Check for loose ignition coil ground circuit.
Engine Cooling System • Check the engine thermostat for proper operation and correct heat range. Refer to
6B4 Engine Cooling – GEN IV V8.
Engine Mechanical Check for the following engine fault conditions. Refer to 6A4 Engine Mechanical –
GEN IV V8.
• low compression, and
• worn valve train components.
Additional Checks • Check the exhaust system for possible restrictions. Refer to 8B Exhaust System.
• Electromagnetic Interference (EMI) on the Crankshaft Position (CKP) sensor can
cause an engine misfire condition.
Using Tech 2, monitor the engine speed parameter. A sudden increase in the
engine speed parameters without moving the throttle position indicates that an
Electromagnetic Interference fault may be present.
Wiring harness routing which may be positioned very close to a high voltage or
high current device such as the following may induce EMI:
• secondary ignition components, and
• motors and generators.
• Check the Torque Converter Clutch (TCC) operation. A TCC that applies too soon
can cause engine detonation, which will trigger spark retard activity. Refer to 7D2
Automatic Transmission – 4L65E – Electrical Diagnosis.
• Test for other TCM related faults that may cause the transmission to operate in the
default mode. Refer to 7D2 Automatic Transmission – 4L65E – Electrical
Diagnosis.
• Check for transmission mechanical faults such as sliding clutch. Refer to 7D3
Automatic Transmission – 4L65E – Hydraulic and Mechanical Diagnosis.
• Check the brake system including the parking brake for sticking or incorrect
operation. Refer to 5A Service and Park Braking System.
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–48
Page 6C4-2–48
4.12 Rough, Unstable, Incorrect Idle or
Stalling
Description
Engine idle speed fluctuates causing the engine to run unevenly. If the engine idle speed drops too low, the engine may
stall
Checks Actions
Preliminary • Perform the Preliminary Checks. Refer to 3.3 Preliminary Checks.
• Check the air filter element and intake air ducts for blockages.
Sensor/System • Check the Throttle Actuator Control (TAC) system. Refer to 6C4-3 Engine
Management GEN IV V8 – Service Operations.
• Check the air intake system and crankcase for air leaks. Refer to 6C4-3 Engine
Management GEN IV V8 – Service Operations.
• Check the PCV System for correct operation. Refer to 6A4 Engine Mechanical –
GEN IV V8.
• Use Tech 2 to monitor the knock sensor system for excessive spark retard activity.
Check for items that cause spark retard activity.
• Using Tech 2, check the Heated Oxygen Sensor (Heated O2 Sensor) operating
parameters. The Heated Oxygen Sensors (Heated O2 Sensors) should respond
quickly to different throttle positions.
Fuel System • Check the fuel system for the following fault conditions. Refer to 8A1 Fuel System.
• restricted fuel filter,
• incorrect fuel pressure, and
• contaminated fuel.
• Check the operation of the fuel injectors. Refer to 6C4-3 Engine Management
GEN IV V8 – Service Operations.
• Perform the fuel injector balance test. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
• Check the items that cause an engine to run rich.
Ignition System • Inspect for moisture or corrosion around the spark plug and ignition coil area.
• Test the ignition coil voltage output. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
• Remove and inspect the spark plugs. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
NOTE
If the spark plugs are fouled, determine the cause of the fouling before
replacing the spark plugs. Refer to 6C4-3 Engine Management GEN IV V8 –
Service Operations.
• Check for loose ignition coil grounds.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–49
Page 6C4-2–49
Checks Actions
Engine Mechanical • Parasitic load on the engine such as the following:
• automatic transmission fault condition, or
• a belt driven accessory fault condition.
• Check for the following engine fault conditions. Refer to 6A4 Engine Mechanical –
GEN IV V8.
• low compression, or
• worn valve train components.
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–50
Page 6C4-2–50
4.13 Surges / Chuggles
Description
With the accelerator pedal in a steady position, the vehicle speeds up and slows down or the engine power fluctuates
Checks Actions
Preliminary Perform the Preliminary Checks. Refer to 3.3 Preliminary Checks.
Sensor/System • Using Tech 2, check the Heated Oxygen Sensor (Heated O2 Sensor) operating
parameters. The Heated Oxygen Sensors (Heated O2 Sensors) should respond
quickly to different throttle positions.
• Test the resistance of the Crankshaft Position (CKP) sensor. The CKP sensor
resistance must be within 700 – 1,200 ohms at all temperatures.
Fuel System • Check the fuel system for the following fault conditions. Refer to 8A1 Fuel System.
• restricted fuel filter,
• incorrect fuel pressure, and
• contaminated fuel.
• Check the operation of the fuel injectors. Refer to 6C4-3 Engine Management
GEN IV V8 – Service Operations.
• Perform the fuel injector balance test. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
• Check the items that cause an engine to run rich.
• Check for fault conditions that can cause an engine to run lean.
Ignition System • Inspect for moisture or corrosion around the spark plug/ignition coil area.
• Test the ignition coil voltage output. Refer to 6C4-3 Engine Management
GEN IV V8 – Service Operations.
• Remove and inspect the spark plugs. Refer to 6C4-3 Engine Management GEN IV
V8 – Service Operations.
NOTE
If the spark plugs are fouled, determine the cause of the fouling before
replacing the spark plugs. Refer to 6C4-3 Engine Management GEN IV V8 –
Service Operations.
• Check for loose ignition coil ground circuit.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–51
Page 6C4-2–51
Checks Actions
Additional Checks • Check the Torque Converter Clutch (TCC) operation. A TCC that applies too soon
can cause engine detonation, which will trigger spark retard activity. Refer to 7D2
Automatic Transmission – 4L65E – Electrical Diagnosis.
• Test the A/C clutch for correct operation. Refer to 2C HVAC Climate Control.
• Check the Evaporative Emissions (EVAP) canister purge solenoid for the following
conditions: Refer to 6C4-3 Engine Management GEN IV V8 – Service Operations.
• stuck open condition, and
• charcoal contamination.
• Check the exhaust system for possible restrictions. Refer to 8B Exhaust System.
• Electromagnetic Interference (EMI) on the Crankshaft Position (CKP) sensor can
cause an engine misfire condition.
Using Tech 2, monitor the engine speed parameter. A sudden increase in the
engine speed parameters without moving the throttle position indicates that an
Electromagnetic Interference fault may be present.
Wiring harness routing which may be positioned very close to a high voltage or
high current device such as the following may induce EMI:
• secondary ignition components, or
• motors and generators.
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–52
Page 6C4-2–52
4.14 Fuel Pump Not Operating
Circuit Description
Positive voltage from the battery is supplied to the fuel pump relay through circuit 240. The ECM applies control voltage
to circuit 465 to activate the fuel pump relay.
The fuel pump relay then applies ignition voltage from the ignition control relay to the fuel pump through circuit 120. The
fuel pump ground circuit is directly connected to ground through circuit 650. Therefore, the application of positive battery
voltage to circuit 120 operates the fuel pump.
The ECM continuously applies control voltage to the fuel pump relay as long as the engine is cranking or running and the
ECM detects Crankshaft Position (CKP) sensor signal pulses. If the CKP sensor signal pulses stop, the ECM deactivates
the fuel pump relay within two seconds, which stops the fuel pump operation.
The diagnostic procedure is directed to the Fuel Pump Not Operating Diagnostic Table if the fuel pump fails to operate.
Fuel Pump Not Operating Diagnostic Aids
Additional Information
• Refer to Section 8A1 Fuel System for details of the fuel pump operation.
• The Fuel Pump Not Working Diagnostic T able is developed with the following assumptions:
• The Immediate Engine Immobilisation System (if activated) is functioning correctly. Ensure that the fuel
system is not immobilised before proceeding with the diagnostic table. Refer to Section 12K Telematics.
• The Crankshaft Position (CKP) sensor circuit is functioning correctly. A fault in the CKP sensor circuit triggers
a DTC. Ensure that the CKP sensor circuit is functioning correctly before proceeding with the diagnostic table.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions .
• Refer to Section 12P Wiring Diagrams to aid in the diagnosis procedures.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
2 Checks if the fuel system is immobilised.
4 Determines if the fault condition is in the coil side or the switch side of the fuel pump relay.
Fuel Pump Not Operating Diagnostic Table
Step Action Yes No
1 Was the Main Diagnostic System Check performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 Check the Immediate Engine Immobilisation System (if activated).
Refer to 12K Telematics.
Was any fault found and rectified? Go to Step 18 Go to Step 3
3 1 Switch On the ignition with the engine not running.
2 Using Tech 2, command the fuel pump relay On and then Off.
3 Observe the fuel pump while commanding the fuel pump On and
Off.
Does the fuel pump turn On and Off? Refer to 7.2 Tech 2
Functions Go to Step 4
4 Does the fuel pump relay produce a clicking noise when the fuel pump
is commanded On and then Off? Go to Step 5 Go to Step 7
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–53
Page 6C4-2–53
Step Action Yes No
5 1 Remove the fuel pump relay. Refer to 12O Fuses, Relays and
Wiring Harnesses.
2 Connect a test light between the fuel pump relay ignition voltage
circuit and a good ground.
3 Switch On the ignition with the engine not running.
Does the test light illuminate? Go to Step 6 Go to Step 9
6 1 Switch Off the ignition.
2 Connect a 3 amp fused jumper wire between the fuel pump relay
ignition voltage circuit and fuel pump supply circuit.
3 Switch On the ignition with the engine not running.
Does the fuel pump operate? Go to Step 13 Go to Step 10
7 1 Remove the fuel pump relay. Refer to 12O Fuses, Relays and
Wiring Harnesses.
2 Connect a test light between the fuel pump relay control circuit
and a good ground.
3 Switch On the ignition with the engine not running.
4 Using Tech 2, command the fuel pump relay On and then Off.
Does the test light turn On and Off when the fuel pump is commanded
On and Off? Go to Step 8 Go to Step 11
8 1 Switch Off the ignition.
2 Connect a test light between the fuel pump relay control circuit
and the fuel pump relay ground circuit.
3 Switch On the ignition with the engine not running.
4 Using Tech 2, command the fuel pump relay On and then Off.
Does the test light turn On and Off when the fuel pump is commanded
On and Off? Go to Step 14 Go to Step 12
9 Repair the high resistance or open circuit fault condition in the fuel
pump relay ignition voltage circuit. Refer to 12P Wiring Diagrams for
information on electrical wiring repair procedures.
Was the repair completed? Go to Step 18
–
10 Test the fuel pump voltage supply circuit for a high resistance or an
open circuit fault condition. Refer to 12P Wiring Diagrams for
information on electrical fault diagnosis.
Was any fault found and rectified? Go to Step 18 Go to Step 14
11 Test the fuel pump relay control circuit for a high resistance or an open
circuit fault condition. Refer to 12P Wiring Diagrams for information on
electrical fault diagnosis.
Was any fault found and rectified? Go to Step 18 Go to Step 15
12 Repair the high resistance or open circuit fault condition in the fuel
pump relay ground circuit. Refer to 12P Wiring Diagrams for
information on electrical wiring repair procedures.
Was the repair completed? Go to Step 18
–
13 Replace the fuel pump relay. Refer to 12O Fuses, Relays and Wiring
Harnesses.
Was the repair completed? Go to Step 18 –
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–54
Page 6C4-2–54
Step Action Yes No
14 Test the fuel pump ground circuit and the fuel pump wiring connector
for poor wiring connection. Refer to 12P Wiring Diagrams for
information on electrical fault diagnosis.
Was any fault found and rectified? Go to Step 18 Go to Step 16
15 Test the ECM wiring connector for shorted terminals or poor wiring
connection. Refer to 12P Wiring Diagrams for information on electrical
fault diagnosis.
Was any fault found and rectified? Go to Step 18 Go to Step 17
16 Replace the fuel pump. Refer to 8A1 Fuel System.
Was the repair completed? Go to Step 18 –
17 Replace the ECM. Refer to 6C4-3 Engine Management GEN IV V8 –
Service Operations.
Was the repair completed? Go to Step 18 –
18 Test the fuel pump operation.
Does the fuel pump operate correctly? Go to Step 19 Go to Step 3
19 Using Tech 2, select the DTC display function.
NOTE
Disregard and clear DTCs that are set while using Tech 2
Output Controls.
Are there any DTCs displayed?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–55
Page 6C4-2–55
4.15 Fuel Pump Continuously Operating
Circuit Description
Positive voltage from the battery is supplied to the fuel pump relay through circuit 240. The ECM applies control voltage
to circuit 465 to activate the fuel pump relay.
The fuel pump relay then applies ignition voltage from the ignition control relay to the fuel pump through circuit 120. The
fuel pump ground circuit is directly connected to ground through circuit 650. Therefore, the application of positive battery
voltage to circuit 120 operates the fuel pump.
The ECM continuously applies control voltage to the fuel pump relay as long as the engine is cranking or running and the
ECM detects a Crankshaft Position (CKP) sensor signal pulses. If the CKP sensor signal pulses stop, the ECM
deactivates the fuel pump relay within two seconds, which stops the fuel pump operation.
The diagnostic procedure is directed to the Fuel Pump Continuously Operating Fault Condition Diagnostic Table if there
is a Fuel Pump Continuously Operating Fault Condition.
Fuel Pump Continuously Operating Diagnostic Aids
Additional Information
• Refer to Section 8A1 Fuel System for details of the fuel pump operation.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Refer to Section 12P Wiring Diagrams to aid in the diagnosis procedures.
Test Description
The following numbers refer to the step numbers in the diagnostic chart:
3 Determines if the fault condition is in the fuel pump voltage supply side or in the fuel pump relay switch side
Fuel Pump Continuously Operating Fault Condition Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch On the ignition with the engine not running.
2 Using Tech 2, command the fuel pump relay On and then Off.
3 Observe the fuel pump while commanding the fuel pump On and
Off.
Does the fuel pump continuously operate? Go to Step 3
Refer to 4.15 Fuel
Pump Continuously
Operating
3 1 Remove the fuel pump relay. Refer to 12O Fuses, Relays and
Wiring Harnesses.
2 Switch On the ignition with the engine not running.
Does the fuel pump continuously operate? Go to Step 6 Go to Step 4
4 1 Connect a test light between the fuel pump relay control circuit
and a good ground.
2 Using Tech 2, command the fuel pump relay On and then Off.
Does the test light turn On and Off when the fuel pump is commanded
On and Off? Go to Step 7 Go to Step 5
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–56
Page 6C4-2–56
Step Action Yes No
5 Test the fuel pump relay control circuit for a short to voltage fault
condition. Refer to 12P Wiring Diagrams for information on electrical
fault diagnosis.
Was any fault found and rectified? Go to Step 10 Go to Step 8
6 Repair the fuel pump voltage supply circuit short to voltage fault
condition. Refer to 12P Wiring Diagrams for information on electrical
wiring repair procedures.
Was the repair completed? Go to Step 10 –
7 Replace the fuel pump relay. Refer to 12O Fuses, Relays and Wiring
Harnesses.
Was the repair completed? Go to Step 10 –
8 Test the ECM wiring connector for shorted terminals or poor wiring
connection. Refer to 12P Wiring Diagrams for information on electrical
fault diagnosis.
Was any fault found and rectified? Go to Step 10 Go to Step 9
9 Replace the ECM. Refer to 6C4-3 Engine Management GEN IV V8 –
Service Operations.
Was the repair completed? Go to Step 10 –
10 Test the fuel pump operation.
Does the fuel pump operate correctly? Go to Step 11 Go to Step 2
11 Using Tech 2, select the DTC display function.
NOTE
Disregard and clear DTCs that are set while using Tech 2
Output Controls.
Are there any DTCs displayed?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–57
Page 6C4-2–57
4.16 Automatic Transmission Functional
Check procedure
Description
The Functional Test Procedure is the first step in diagnosing mechanical or hydraulic transmission conditions and
provides procedures and references to other service information sections for specific diagnostic information
Step Action Yes No
1 NOTE
Engine performance can greatly affect transmission
performance. Ensure that the complaint is not the result of
poor engine performance before continuing.
Verify the customer complaint.
Has the customer complaint been verified? Go to Step 2 –
2 NOTE
Many transmissions have default actions that take place
once a DTC fault is detected. These actions may be
interpreted as being a transmission concern.
Has the Engine Main Diagnostic System Check been performed? Go to Step 3
Refer to
3.4 Diagnostic
System Check
3 Perform the Transmission Fluid Checking Procedure. Refer to
7D3 Automatic Transmission – 4L65E – Hydraulic and Mechanical
Diagnosis.
Is the procedure complete? Go to Step 4 –
4 1 Perform a visual inspection. Look for the following conditions:
• Vehicle damage.
• Transmission oil pan damage. Refer to 7D4 Automatic
Transmission – 4L65E – On-vehicle Servicing.
• Worn or damaged suspension parts. Refer to 3 Front
Suspension.
• Worn or damaged steering parts. Refer to 9 Steering.
• Transmission range selector linkage damaged or out of
adjustment. Refer to 7D4 Automatic Transmission – 4L65E
– On-vehicle Servicing.
• Loose, worn, damaged or missing:
• mounts or struts.
• brackets.
• mounting hardware.
2 Transmission cooler or cooler line restrictions. Refer to 7D4
Automatic Transmission – 4L65E – On-vehicle Servicing.
3 Fluid leaks. Refer to 7D4 Automatic Transmission – 4L65E –
On-vehicle Servicing.
Was any fault found?
Go to the
Appropriate Repair
or Diagnosis
Section Go to Step 5
5 Perform the Road Test Procedure. Refer to 7D3 Automatic
Transmission – 4L65E – Hydraulic and Mechanical Diagnosis.
Did the vehicle exhibit any objectionable condition? Go to Step 6 System OK
6 Did the vehicle exhibit objectionable torque converter operation? Go to Step 15 Go to Step 7
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–58
Page 6C4-2–58
Step Action Yes No
7 Did the vehicle exhibit a noise condition? Refer to 7D3
Automatic
Transmission –
4L65E – Hydraulic
and Mechanical
Diagnosis Go to Step 8
8 Did the vehicle exhibit a vibration condition? Go to Step 9 Go to Step 10
9 Did the vibration occur only during Torque Converter Clutch (TCC)
apply or release?
Go to Step 15
Refer to 7D3
Automatic
Transmission –
4L65E – Hydraulic
and Mechanical
Diagnosis
10 Did the vehicle exhibit a shift speed condition such as low or high shift
speeds? Refer to 7D3
Automatic
Transmission –
4L65E – Hydraulic
and Mechanical
Diagnosis Go to Step 11
11 Did the vehicle exhibit any of the following shift quality (feel)
conditions?
• Harsh, soft, delayed or no engagement.
• Harsh, soft or delayed shifts.
• Shift shudder, flare or tie-up. Go to Step 12 Go to Step 13
12 Perform the Line Pressure Check Procedure. Refer to 7D3 Automatic
Transmission – 4L65E – Hydraulic and Mechanical Diagnosis.
Is the line pressure within specification?
Go to Step 13
Refer to 7D3
Automatic
Transmission –
4L65E – Hydraulic
and Mechanical
Diagnosis
13 Did the vehicle exhibit any of the following shift pattern conditions?
• No upshift or downshift.
• Only one or two forward gears.
• No First, Second, Third or Fourth gear.
• Slipping.
• Non-first gear start.
Refer to 7D3
Automatic
Transmission –
4L65E – Hydraulic
and Mechanical
Diagnosis Go to Step 14
14 Did the vehicle exhibit any of the following range performance
conditions?
• No Park, Reverse or Drive.
• No engine braking.
• No gear selection.
• Incorrect gear selection.
Refer to 7D3
Automatic
Transmission –
4L65E – Hydraulic
and Mechanical
Diagnosis System OK
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–59
Page 6C4-2–59
Step Action Yes No
15 1 Refer to Torque Converter Diagnosis Procedure, in 7D3
Automatic Transmission – 4L65E – Hydraulic and Mechanical
Diagnosis.
2 Did the vehicle exhibit any of the following TCC conditions?
• Stuck on or off.
• Early or late engagement.
• Incorrect apply or release.
• Soft or harsh apply.
• Clunk or shudder.
• No torque multiplication.
• Excessive slip.
• Poor acceleration.
• Engine stalls.
Refer to 7D3
Automatic
Transmission –
4L65E – Hydraulic
and Mechanical
Diagnosis System OK
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–60
Page 6C4-2–60
4.17 Automatic Transmission Power /
Economy Switch
Circuit Description
The driver can select three transmission shift modes, economy, power, or cruise. Economy and power modes are
selected using the PWR switch mounted in the centre console, and cruise is selected by the CRUISE switch on the
steering column stalk. The PWR switch is wired directly to the ECM. When power is selected, the transmission shifts at
higher engine RPM, and uses higher line pressure and less torque converter lock-up. When cruise control is activated the
transmission overrides the power or economy mode and enters cruise mode, which provides shift points suitable for
operation with the cruise control on.
The transmission supplies ignition voltage to the power/economy switch via circuit 553. When the switch is depressed,
the circuit is grounded, and the ECM detects that the voltage on circuit 553 is low. Each depression of the PWR switch
toggles the transmission mode, that is if the transmission was in power mode, pressing the PWR switch changes the
transmission mode to economy, and vice versa.
Automatic Transmission Power / Economy Switch Diagnostic Aids
Additional Information
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Refer to Section 12P Wiring Diagrams to aid in the diagnosis procedures.
Automatic Transmission Power / Economy Switch Diagnostic Table
Step Action Yes No
1 Was the Main Diagnostic System Check performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch on the ignition with the engine not running.
2 Install Tech 2.
3 Press the transmission PWR switch.
Does Tech 2 indicate a change between power and economy modes? Go to Step 3 Go to Step 5
3 Is the Power Icon in the instrument panel MFD active when T ech 2
displays Power? Go to Step 4 Refer to 12C
Instrumentation
4 Is the Power Icon in the instrument panel MFD inactive when Tech 2
displays Economy? The power /
economy switch
operation is
serviceable Refer to 12C
Instrumentation
5 1 Disconnect connector S22 from the PWR switch.
2 Connect a 3 amp fused jumper wire between the PWR switch
ignition voltage and ground circuits.
Does Tech 2 indicate a change between power and economy modes
each time the circuits are bridged? Go to Step 7 Go to Step 6
6 Connect a 3 amp fused jumper wire between the PWR switch ignition
voltage circuit and a known ground.
Does Tech 2 indicate a change between power and economy modes
each time the circuit is grounded? Go to Step 12 Go to Step 9
7 Check the PWR switch connector for a poor wiring / terminal
connection.
Was any fault found and rectified? Go to Step 13 Go to Step 8
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–61
Page 6C4-2–61
Step Action Yes No
8 Replace the PWR switch.
Was the repair completed? Go to Step 13 –
9 Test the PWR switch ignition voltage circuit for a high resistance, open
circuit; short to ground or short to voltage fault condition. Refer to 12P
Wiring Diagrams for information on electrical fault diagnosis.
Was any fault found and rectified? Go to Step 13 Go to Step 10
10 Test the ECM wiring connector for shorted terminals or poor wiring
connection. Refer to 12P Wiring Diagrams for information on electrical
fault diagnosis.
Was any fault found and rectified? Go to Step 13 Go to Step 11
11 Replace the ECM. Refer to 6C3-3 Engine Management GEN IV V8 –
Service Operations.
Was the repair completed? Go to Step 13 –
12 Repair the high resistance, open circuit, or short to voltage fault
condition in the PWR switch ground circuit. Refer to 12P Wiring
Diagrams for information on electrical fault diagnosis.
Was the repair completed? Go to Step 13 –
13 Test the PWR switch operation.
Does the PWR switch operate correctly? Go to Step 14 Go to Step 2
14 Using Tech 2, select the DTC display function.
NOTE
Disregard and clear DTCs that are set while using Tech 2
Output Controls.
Are there any DTCs displayed?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–62
Page 6C4-2–62
5 Functional Checks
5.1 General Information
The items detailed in the following pages are to be used when there is a customer complaint and there are no diagnostic
trouble codes set, or one or more of the Tech 2 data values are not within the typical values. They are also to be used
when instructed from a DTC table. Before using these tables, you should refer to 4 Symptoms Diagnostics, which may
direct you to using this Section.
The purpose of these tables is to diagnose Engine Control Module (ECM) controlled components or sub-systems that do
not have diagnostic trouble codes assigned to them. Another purpose of these tables is for Technicians who feel
confident that a particular part of the sub-system is not operating properly and wants only to check that particular item for
proper operation without going through lengthy diagnostic procedures.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–63
Page 6C4-2–63
5.2 Fuel Injector Coil Test
1 Depressurise the fuel system, refer to Section 8A1 Fuel System.
2 Turn the ignition off.
3 Remove the engine dress cover, refer to Section 6A4 Engine Mechanical – GEN IV V8.
4 Using Tech 2, observe the engine coolant temperature (ECT), refer to 0C Tech 2. If the ECT is between
10 – 35°C, refer to Engine Coolant Temperature Between 10 – 35(C, or if the ECT is outside this range, refer to
Engine Coolant Temperature Outside 10 – 35(C.
Engine Coolant Temperature Between 10 – 35°C
Step Action Value(s) Yes No
1 1 Set the amperage supply selector switch on the
fuel injector coil/balance tester (1), special tool
J 39021 to the Coil Test 0.5 Amp position. Refer
to Figure 6C4-2 – 10.
2 Connect the fuel injector tester leads (4 and 5) to
B+ and ground.
3 Connect the digital multimeter (2) positive and
negative lead to the fuel injector tester. Set the
multimeter to read DC Voltage.
4 Connect the fuel injector tester to a fuel injector.
5 Press the Push to Start Test button on the fuel
injector tester.
6 Observe and record the voltage reading on the
digital multimeter.
NOTE
The voltage reading may rise during the test.
Record the voltage reading after one second
of the test.
7 Repeat steps 4 through 6 for each fuel injector.
NOTE
The table in Figure 6C4-2 – 11 shows an
example of the results from a fuel injector
coil test.
Did any fuel injector have an erratic voltage reading
(large fluctuations in voltage that did not stabilise), or
voltage readings outside of the specified value? 5.5 – 6.6 V
Replace the faulty
fuel injector/s. Refer
to 6C4-3 Engine
Management –
Service Operations
– GEN IV V8 System OK
When all repairs are completed, check the system for fuel leaks and correct op eratio n.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–64
Page 6C4-2–64
Engine Coolant Temperature Outside 10 – 35°C
Step Action Value(s) Yes No
1 1 Set the amperage supply selector switch on the
fuel injector coil/balance tester (1), special tool
J 39021 to the Coil Test 0.5 Amp position. Refer
to Figure 6C4-2 – 10.
2 Connect the fuel injector tester leads (4 and 5) to
B+ and ground.
3 Connect the digital multimeter (2) positive and
negative lead to the fuel injector tester. Set the
multimeter to read DC Voltage.
4 Connect the fuel injector tester to a fuel injector.
5 Press the Push to Start Test button on the fuel
injector tester.
6 Observe and record the voltage reading on the
digital multimeter.
NOTE
The voltage reading may rise during the test.
Record the voltage reading after one second
of the test.
7 Repeat steps 4 through 6 for each fuel injector.
8 Identify the highest voltage reading recorded from
the six fuel injectors tested that is 9.5 V or below.
NOTE
Disregard those voltage readings that are
above 9.5 V. Voltage readings above 9.5 V
indicate a faulty fuel injector.
9 Subtract the remaining voltage readings recorded
in Step 8, from the highest voltage reading.
Are any of the values recorded in Step 9 greater than
the specified value? 0.6 V Go to Step 2 System OK
2 Replace any fuel injector that had any of the following:
• a subtracted value exceeding 0.6 V,
• an initial reading above 9.5 V, and
• an erratic reading.
NOTE
The table in Figure 6C4-2 – 12 shows an
example of the results from a fuel injector
coil test.
Has the repair been completed? – System OK –
When all repairs are completed, check the system for fuel leaks and correct op eratio n.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–65
Page 6C4-2–65
Figure 6C4-2 – 10
Legend
1 Fuel Injector Coil/Balance Tester – Special Tool J39021
2 Digital Multimeter
3 Fuel Injector Harness Connector
4 To Battery Positive Terminal
5 Battery Earth
Fuel Injector Coil Test Exampl e – En gine Coolant Temperature between 10 – 35°C (Typical Values Shown)
Fuel Injector No. Voltage Reading Pass / Fail (acceptable range 5.5 - 6.6V)
1 6.6 Pass
2 5.4 Fail
3 6.2 Pass
4 6.1 Pass
5 6.7 Fail
6 6.0 Pass
7 6.2 Pass
8 6.7 Fail
Figure 6C4-2 – 11
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–66
Page 6C4-2–66
Fuel Injector Coil Test Example – Engi n e Co o lant Temperature Above / Below 10 – 35°C (Typical Values Shown )
Fuel Injector No. Voltage Reading Highest Voltage Reading
(9.5V or less) Subtracted Value
(acceptable voltage 0.6 V) Pass / Fail
1 9.8 – –
Fail
2 6.4 7.0 0.6 Pass
3 6.9 7.0 0.1 Pass
4 5.8 7.0 1.2 Fail
5 7.0 7.0 0.0 Pass
6 6.3 7.0 0.7 Fail
7 6.9 7.0 0.1 Pass
8 6.4 7.0 0.6 Pass
Figure 6C4-2 – 12
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–67
Page 6C4-2–67
5.3 Fuel Injector Balance Test
To avoid irregular fuel pressure readings, do
not perform this procedure if the engine
coolant temperature is greater than 94° C.
Fuel Injector Balance Test – With Tech 2
1 Check the engine coolant temperature is less than 94°C.
2 Perform the fuel injector coil test and replace any fuel injectors that are not functioning correctly before proceeding.
Refer to 5.2 Fuel Injector Coil Test.
3 Perform the fuel system pressure check and ensure the fuel system is functioning correctly before proceeding with
the fuel injector balance test. Refer to Section 8A1 Fuel System.
4 While the fuel pressure gauge is still connected to the fuel pressure test point, pressurise the fuel system. Refer to
Section 8A1 Fuel System.
5 When the fuel pressure reading stabilises, record the fuel pressure reading indicated by the fuel pressure gauge.
NOTE
The fuel pressure reading taken in Step 5 is
known as the first pressure reading.
6 Connect Tech 2 to the data link connector (DLC) and turn the ignition on.
7 On Tech 2 select Engine / V8 Engine / Actuator Test / Fuel Injector Balance.
8 Follow the Tech 2 prompts, recording the fuel pressure gauge reading for each injector.
NOTE
The fuel pressure readings taken in Step 8 are
known as the second pressure reading
9 Perform the Fuel Injector Pressure Drop Calculation in this Section.
Fuel Injector Balance Test – Without Tech 2
1 Check the engine coolant temperature is less than 94°C.
2 Perform the fuel injector coil test and replace any fuel injectors that are not functioning correctly before proceeding.
Refer to 5.2 Fuel Injector Coil Test.
3 Perform the fuel system pressure check and ensure the fuel system is functioning correctly before proceeding with
the fuel injector balance test. Refer to Section 8A1 Fuel System.
4 While the fuel pressure gauge is still connected to the fuel pressure test point, pressurise the fuel system. Refer to
Section 8A1 Fuel System.
5 When the fuel pressure reading stabilises, record the fuel pressure reading indicated by the fuel pressure gauge.
NOTE
The fuel pressure reading taken in Step 5 is
known as the first pressure reading.
6 Connect Tool No. J 39021 Fuel Injector Tester (1), and Tool No. J 44602 (3) to the fuel injector connector. Refer to
Figure 6C4-2 – 13.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–68
Page 6C4-2–68
Figure 6C4-2 – 13
Legend
1 Fuel Injector Tester – Special Tool J39021
2 Fuel Pressure Gauge – Special Tool SD28018
3 Fuel Injector Harness Adapter – Special Tool J44602
4 To Battery Positive Terminal
5 Battery Earth
6 First Pressure Reading
7 Second Pressure Reading
7 Connect the fuel injector tester battery positive lead (4) and battery negative lead (5) to the battery, refer to Figure
6C4-2 – 13.
8 Set the amperage supply selector of the fuel injector tester to the Balance Test 0.5 – 2.5 A position.
As the fuel pressure tends to increase after
the fuel injector stop s fuel delivery, record the
fuel pressure value immediately after the fuel
injector stops fuel delivery. Do not record the
higher fuel pressure value.
9 Press the Push to Start Test Button on the fuel injector tester to activate the fuel injector.
10 Record the fuel pressure reading indicated by the fuel pressure gauge.
NOTE
The fuel pressure readings taken in Step 10 is
known as the second pressure reading
11 Repeat the balance test pressure reading for each fuel injector.
12 Perform the Fuel Injector Pressure Drop Calculation in this Section.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–69
Page 6C4-2–69
Fuel Injector Pressure Drop Calculation
Fuel Injector Balance Test Example – Typical Values Sho wn
Cylinder 1 2 3 4 5 6 7 8
1st
Pressure
Reading
360 kPa 360 kPa 360 kPa 360 kPa 360 kPa 360 kPa 360 kPa 360 kPa
2nd
Pressure
Reading
155 kPa 146 kPa 155 kPa 131 kPa 155 kPa 200 kPa 146 kPa 150 kPa
Amount of
Pressure
Drop
205 kPa 214 kPa 205 kPa 229 kPa 205 kPa 160 kPa 214 kPa 210 kPa
Average
Range
194 - 214
kPa
Injector
OK Injector
OK Injector
OK Replace
fuel
injector –
too much
pressure
drop
Injector
OK Replace
fuel
injector –
too little
pressure
drop
Injector
OK Injector
OK
Figure 6C4-2 – 14
1 Subtract the second pressure reading from the first pressure reading to calculate the pressure drop value. Refer to
Figure 6C4-2 – 14, typical results.
2 Calculate the pressure drop value for each fuel injector.
3 Add all the individual pressure drop values of each fuel injector to calculate the total pressure drop.
4 Divide the total pressure drop by the number of fuel injectors to calculate the average pressure drop.
Fuel Injector Pressure Drop Analysis
1 A fuel injector is faulty if its pressure drop value deviates from the average pressure drop by more than 10 kPa.
Do not repeat any portion of the test before
running the engine to prevent the engine from
flooding.
2 Re-test any fuel injector that does not meet the specification.
3 Replace all faulty fuel injectors, refer to Section 6C4-3 Engine Management – GEN IV V8 – Service Operations.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–70
Page 6C4-2–70
5.4 Fuel Injector Leak Down Test
1 Turn the ignition switch OFF.
2 Remove the engine dress cover, refer to Section 6A4 Engine Mechanical – GEN IV V8.
Clean around the area where the fuel
injectors enter the intake manifold.
3 Remove the bolt (1), three places, attaching the fuel
rail to the intake manifold.
Care must be taken when removing the fuel
rail and injector assembly to prevent damage
to the injector spray tips and in jector harness
connector terminals.
Support the fuel rail and injector assembly
after removal.
4 Lift up and support the fuel rail and injector assembly.
NOTE
Do not disconnect the fuel feed hose from the
fuel rail.
Figure 6C4-2 – 15
5 Place a board (1) with a sheet of clean paper (2),
preferably white, onto the intake manifold.
6 Using Tech 2, enable the fuel pump to pressurise the
fuel system, refer to Section 0C Tech 2 for this
procedure.
7 Whilst the fuel system is pressurised, check the
following:
• Signs of fuel stains on the paper (3).
• Signs of weeping at the fuel injector spray
tips (4).
8 If any of the above conditions are present, replace the
leaking fuel injector/s, refer to Section 6C4-3 Engine
Management – GEN IV V8 – Service Operations.
9 Carefully reinstall the fuel rail and injector assembly.
Figure 6C4-2 – 16
Ensure the fuel injectors are correctly seated
in the intake manifold, and the fuel rail
attaching brackets are correctly located prior
to tightening the attaching bolts.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–71
Page 6C4-2–71
10 Tighten the fuel rail bolts to the correct torque specification.
Fuel rail attaching bolt
torque specification ..................................8.0 – 12.0 Nm
11 Reinstall the engine dress cover, refer to Section 6A4 Engine Mechanical – GEN IV V8.
12 Inspect the fuel rail and quick connect fitting for leaks, refer to Section 8A1 Fuel System.
13 Road test the vehicle and check for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–72
Page 6C4-2–72
5.5 Alcohol/Contaminants in Fuel Diagnosis
Without Special Tool
Description
Water contamination in the fuel system may cause driveability conditions such as hesitation, stalling, no start, or misfires
in one or more cylinders. Water may collect near a single fuel injector at the lowest point in the fuel rail, and cause a
misfire in that cylinder. If the fuel system is contaminated with water, inspect the fuel system components for rust, or
deterioration.
Alcohol concentrations more than 10 percent in the fuel can be detrimental to fuel system components. Alcohol
contamination may cause fuel system corrosion, deterioration of rubber components, and subsequent fuel filter
restriction. Fuel contaminated with alcohol may cause driveability conditions such as hesitation, lack of power, stalling, or
no start. Some types of alcohol are more detrimental to fuel system components than others.
Alcohol in Fuel Testing Procedure
The fuel sample should be drawn from the bottom of the tank so that any water present in the tank will be detected. The
sample should be bright and clear. If alcohol contamination is suspected then use the following procedure to test the fuel
quality.
• Using a 100 ml specified cylinder with 1 ml graduation marks, fill the cylinder with fuel to the 90 ml mark.
• Add 10 ml of water to bring the total fluid volume to 100 ml and install a stopper.
• Shake the cylinder vigorously for 10 – 15 seconds.
• Carefully loosen the stopper to release the pressure.
• Re-install the stopper and shake the cylinder vigorously again for 10 – 15 seconds.
• Put the cylinder on a level surface for approximately 5 minutes to allow adequate liquid separation.
If alcohol is present in the fuel, the volume of the lower layer, that now contains both alcohol and water, will be more than
10 ml. For example, if the volume of the lower layer is increased to 15 ml, this indicates at least 5 percent alcohol in the
fuel. The actual amount of alcohol may be somewhat more because this procedure does not extract all of the alcohol
from the fuel.
Particulate Contaminants in Fuel Testing Procedure
The fuel sample should be drawn from the bottom of the tank so that any contaminants present in the tank will be
detected. The sample should be bright and clear. If the sample appears cloudy or contaminated with water as indicated
by a water layer at the bottom of the sample, use the following procedure to diagnose the fuel.
• Using an approved fuel container, draw approximately 0.5 litre of fuel.
• Place the cylinder on a level surface for approximately 5 minutes to allow settling of the particulate contamination.
Particulate contamination will show up in various shapes and colours. Sand will typically be identified by white or light
brown crys tals. Rubber will appear as black and irregular particles. If particles are found, clean the entire fuel system
thoroughly. Refer to Section 8A1 Fuel System.
With Special Tool
Description
Water contamination in the fuel system may cause driveability conditions such as hesitation, stalling, no start, or misfires
in one or more cylinders. Water may collect near a single fuel injector at the lowest point in the fuel injection system, and
cause a misfire in that cylinder. If the fuel system is contaminated with water, inspect the fuel system components for rust
or deterioration.
Ethanol concentrations of greater than 10 percent can cause driveability conditions and fuel system deterioration. Fuel
with more than 10 percent ethanol could result in driveability conditions such as hesitation, lack of power, stalling , or no
start. Excessive concentrations of ethanol used in vehicles not designed for it may cause fuel system corrosion,
deterioration of rubber components, and fuel filter restriction.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–73
Page 6C4-2–73
Test Procedure
Test the fuel composition using J 44175 Fuel Composition Tester and J44175-3 Instruction Manual.
If water appears in the fuel sample, perform the following steps:
• Clean the fuel system. Refer to Section 8A1 Fuel System.
• Replace the fuel filter. Refer to Section 8A1 Fuel System.
• Subtract 50 from the reading on the DMM to obtain the percentage of alcohol in the fuel sample. Refer to the
examples in the Fuel Composition Test Examples table.
• If the fuel sample contains more than 15 percent ethanol, add fresh, unleaded fuel to the vehicle fuel tank.
Fuel Composition Test Examples Frequency (Hz) Subtract 50 Ethanol Percent
Example A 50 Hz –50 0
Example B 65 Hz –50 15
Example C 129 Hz –50 79
If, after testing, the ethanol percentage is still more than 15 percent, replace the fuel in the vehicle. Refer to
Section 8A1 Fuel System.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–74
Page 6C4-2–74
5.6 Crankshaft Position (CKP) System
Variation Learn Procedure
Description
The crankshaft variation learn procedure is to allow the ECM to recognise any variation in reluctor ring so that the car
dose not incorrectly diagnoses this variation as a misfire.
Using Tech 2 select
• Engine.
• Programming.
• Learn crankshaft sensor error.
• Start car and run in Park/Netural with hand brake applied.
• Increase engine speed to 4000 RPM.
• Release throttle as soon as fuel cut occurs.
• Learn procedure is complete.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–75
Page 6C4-2–75
5.7 Electronic Ignition (EI) System Diagnosis
Circuit Description
The engine control module (ECM) controls the ignition coils by pulsing the ignition control (IC) circuits, which triggers an
ignition coil and fires the spark plug. The ECM controls the sequencing and the timing of each ignition coil. The ignition
system consist of the following components:
• The eight ignition coils
• The crankshaft position (CKP) sensor
• The camshaft position (CMP) sensors
• The ECM
The ignition coils use the following circuits:
• An IC circuit
• An ignition 1 voltage circuit
• Two ground circuits
Additional Information
• Use the J 35616-B Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a
component harness connector.
• Inspect the ignition coils for aftermarket devices. An aftermarket device connected to the ignition coil circuits, may
cause a condition with the ignition coils.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• To assist diagnosis, refer to 2 Wiring Diagrams and Connector Charts for the system wiring diagram and connector
charts.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
4 The ignition coils for each bank are fused separately. If a fuse opens or the ignition 1 voltage circuit opens between
the fuse and the splice, all the ignition coils for one bank of the engine would be inoperative. If the ground circuit
opens at the engine block, the ignition coils would be inoperative for one bank of the engine.
5 This step tests for an open or a high resistance in the ignition 1 voltage circuit of the ignition coil. If the DMM does
not display near battery voltage there is an open or a high resistance in the circuit.
6 This step determines if the ground circuit is open. If the circuit is open, the ignition coils would be inoperative for
one bank of the engine.
7 This step determines if the ignition 1 voltage circuit is shorted to ground. If the fuse is open, the ignition coils would
be inoperative for one bank of the engine.
Diagnostic Table
Step Action Value(s) Yes No
1 Has the Diagnostic System Check been performed? — Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 Were you sent here from DTC P0300? — Go to Step 3
Go to 6.14 DTC
P0300, P1380,
P1381
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–76
Page 6C4-2–76
Step Action Value(s) Yes No
3
1 Start the engine.
2 Allow the engine to reach operating temperature.
3 Operate the engine at 2,000 rpm.
4 Monitor all of the Misfire Current Counters with a
scan tool. There are a total of 8 counters,
1 counter per cylinder.
Are any of the Misfire Current Counters incrementing?
—
Go to Step 4
Go to
4.2 Intermittent
Fault Conditions
4 Are all the misfire counters incrementing for one bank of
the engine? — Go to Step 7 Go to Step 5
5
1 Ignition OFF.
2 Disconnect the appropriate ignition coil.
3 Ignition ON, engine OFF.
4 Connect a test lamp between the battery voltage
circuit of the ignition coil and a good ground.
5 Measure the voltage between the probe of the test
lamp and a good ground with a DMM. Refer to
12P Wiring Diagrams for the procedure to
measure voltage drop.
Is the voltage at the specified value?
B+
Go to Step 6 Go to Step 9
6
Connect the test lamp between the battery voltage
circuit of the ignition coil and to each ground circuit of
the ignition coil.
Does the test lamp illuminate at each ground circuit?
—
Go to Step 8 Go to Step 10
7
Test the battery voltage circuit for an open or high
resistance at the splice of the affected bank of ignition
coils. Refer to 12P Wiring Diagrams for circuit testing
procedures.
Did you find and correct the condition?
—
Go to Step 12 Go to Step 10
8
Test for an intermittent and for a poor connection at the
ignition coil. Refer to 12P Wiring Diagrams for circuit
testing procedures.
Did you find and correct the condition?
—
Go to Step 12 Go to Step 11
9
NOTE
The battery voltage circuit is shared with
other components. Disconnecting a
component on the shared battery voltage
circuit may isolate a shorted component.
Review the electrical schematic and
diagnose the shared circuits and
components.
1 Repair a short to ground, an open or high
resistance in the ignition 1 voltage circuit. Refer to
12P Wiring Diagrams for wiring repair procedures.
2 Replace the fuse as necessary.
Did you complete the repair?
—
Go to Step 12 —
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–77
Page 6C4-2–77
Step Action Value(s) Yes No
10
Repair the open or high resistance in the ground circuit.
Refer to 12P Wiring Diagrams for wiring repair
procedures.
Did you complete the repair?
—
Go to Step 12 —
11 Replace the ignition coil. Refer to 6C4-3 Engine
Management – GEN IV V8 – Service Operations.
Did you complete the replacement? — Go to Step 12 —
12
1 Connect all disconnected components.
2 Use Tech 2 to clear the DTC/s.
3 Start the engine.
4 Observe the Capture Info with Tech 2.
Do any of the misfire counters increment?
—
Go to Step 2 Go to Step 13
13 Using Tech 2, select the DTC display function.
Are there any DTCs displayed? — Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, clear all DTCs and verify correct operation
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–78
Page 6C4-2–78
6 Diagnostic Trouble Code Tables
6.1 DTC List in Ascending Order
As a number of diagnostic tables cater for multiple DTC numbers, a specific DTC table may be difficult to locate. To
make a specific DTC diagnostic table easier to find, the next list is arranged in numerical ascending order. The actual
diagnostic table can be located by selecting the link provided.
DTC Description Diagnostic Table
P0016 Crankshaft Position (CKP)-Camshaft Position (CMP)
Correlation Bank 1 Sensor A 6.2 DTC P0016
P0030 Heated O2 Sensor Heater Control Circuit Bank 1 Sensor 1 6.3 DTC P0030, P0036, P0050 P0053,
P0054, P0056, P0059, P0060, P0135,
P0141, P0155, P0161
P0036 Heated O2 Sensor Heater Control Circuit Bank 1 Sensor 2 6.3 DTC P0030, P0036, P0050 P0053,
P0054, P0056, P0059, P0060, P0135,
P0141, P0155, P0161
P0050 Heated O2 Sensor Heater Control Circuit Bank 2 Sensor 1 6.3 DTC P0030, P0036, P0050 P0053,
P0054, P0056, P0059, P0060, P0135,
P0141, P0155, P0161
P0053 Heated O2 Sensor Heater Resistance Bank 1 Sensor 1 6.3 DTC P0030, P0036, P0050 P0053,
P0054, P0056, P0059, P0060, P0135,
P0141, P0155, P0161
P0054 Heated O2 Sensor Heater Resistance Bank 1 Sensor 2 6.3 DTC P0030, P0036, P0050 P0053,
P0054, P0056, P0059, P0060, P0135,
P0141, P0155, P0161
P0056 Heated O2 Sensor Heater Control Circuit Bank 2 Sensor 2 6.3 DTC P0030, P0036, P0050 P0053,
P0054, P0056, P0059, P0060, P0135,
P0141, P0155, P0161
P0059 Heated O2 Sensor Heater Resistance Bank 2 Sensor 1 6.3 DTC P0030, P0036, P0050 P0053,
P0054, P0056, P0059, P0060, P0135,
P0141, P0155, P0161
P0060 Heated O2 Sensor Heater Resistance Bank 2 Sensor 2 6.3 DTC P0030, P0036, P0050 P0053,
P0054, P0056, P0059, P0060, P0135,
P0141, P0155, P0161
P0068 MAP/MAF - Throttle Position Correlation 6.4 DTC P0068
P0101 Mass Air Flow (MAF) Sensor Performance 6.5 DTC P0101, P0102, P0103, P1101
P0102 Mass Air Flow (MAF) Sensor Circuit Low 6.5 DTC P0101, P0102, P0103, P1101
P0103 Mass Air Flow (MAF) Sensor Circuit High 6.5 DTC P0101, P0102, P0103, P1101
P0106 Manifold Absolute Pressure (MAP) Sensor Performance 6.6 DTC P0106, P0107, P0108
P0107 Manifold Absolute Pressure (MAP) Sensor Circuit Low 6.6 DTC P0106, P0107, P0108
P0108 Manifold Absolute Pressure (MAP) Sensor Circuit High 6.6 DTC P0106, P0107, P0108
P0112 Intake Air Temperature (IAT) Sensor Circuit Low 6.7 DTC P0112, P0113, P1101
P0113 Intake Air Temperature (IAT) Sensor Circuit High 6.7 DTC P0112, P0113, P1101
P0116 Engine Coolant Temperature (ECT) Sensor Performance 6.8 DTC P0116, P0117, P0118, P0128,
P1258
P0117 Engine Coolant Temperature (ECT) Sensor Circuit Low 6.8 DTC P0116, P0117, P0118, P0128,
P1258
P0118 Engine Coolant Temperature (ECT) Sensor Circuit High 6.8 DTC P0116, P0117, P0118, P0128,
P1258
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–79
Page 6C4-2–79
DTC Description Diagnostic Table
P0120 Throttle Position (TP) Sensor 1 Circuit 6.9 DT C P0120, P0121, P0122, P0123,
P0220, P0222, P0223, P1516, P2101,
P2135.
P0121 Throttle Position (TP) Sensor 1 Performance 6.9 DTC P0120, P0121, P0122, P0123,
P0220, P0222, P0223, P1516, P2101,
P2135.
P0122 Throttle Position (TP) Sensor 1 Circuit Low 6.9 DTC P0120, P0121, P0122, P0123,
P0220, P0222, P0223, P1516, P2101,
P2135.
P0123 Throttle Position (TP) Sensor 1 Circuit High 6.9 DTC P0120, P0121, P0122, P0123,
P0220, P0222, P0223, P1516, P2101,
P2135.
P0128 Engine Coolant Temperature (ECT) Below Thermostat
Regulating Temperature 6.8 DTC P0116, P0117, P0118, P0128,
P1258
P0131 Heated O2 Sensor Circuit Low Voltage Bank 1 Sensor 1 6.10 DTC P0131, P0132, P0133, P0134,
P0137, P0138, P0140, P0151, P0152,
P0153, P0154, P0157, P0158, P0160,
P1133, P1153, P2A01, P2A04
P0132 Heated O2 Sensor Circuit High Voltage Bank 1 Sensor 1 6.10 DTC P0131, P0132, P0133, P0134,
P0137, P0138, P0140, P0151, P0152,
P0153, P0154, P0157, P0158, P0160,
P1133, P1153, P2A01, P2A04
P0133 Heated O2 Sensor Slow Response Bank 1 Sensor 1 6.10 DTC P0131, P0132, P0133, P0134,
P0137, P0138, P0140, P0151, P0152,
P0153, P0154, P0157, P0158, P0160,
P1133, P1153, P2A01, P2A04
P0134 Heated O2 Sensor Circuit Insufficient Activity Bank 1
Sensor 1 6.10 DTC P0131, P0132, P0133, P0134,
P0137, P0138, P0140, P0151, P0152,
P0153, P0154, P0157, P0158, P0160,
P1133, P1153, P2A01, P2A04
P0135 Heated O2 Sensor Heater Performance Bank 1 Sensor 1 6.3 DTC P0030, P0036, P0050 P0053,
P0054, P0056, P0059, P0060, P0135,
P0141, P0155, P0161
P0137 Heated O2 Sensor Circuit Low Voltage Bank 1 Sensor 2 6.10 DTC P0131, P0132, P0133, P0134,
P0137, P0138, P0140, P0151, P0152,
P0153, P0154, P0157, P0158, P0160,
P1133, P1153, P2A01, P2A04
P0138 Heated O2 Sensor Circuit High Voltage Bank 1 Sensor 2 6.10 DTC P0131, P0132, P0133, P0134,
P0137, P0138, P0140, P0151, P0152,
P0153, P0154, P0157, P0158, P0160,
P1133, P1153, P2A01, P2A04
P0140 Heated O2 Sensor Circuit Insufficient Activity Bank 1
Sensor 2 6.10 DTC P0131, P0132, P0133, P0134,
P0137, P0138, P0140, P0151, P0152,
P0153, P0154, P0157, P0158, P0160,
P1133, P1153, P2A01, P2A04
P0141 Heated O2 Sensor Heater Performance Bank 1 Sensor 2 6.3 DTC P0030, P0036, P0050 P0053,
P0054, P0056, P0059, P0060, P0135,
P0141, P0155, P0161
P0151 Heated O2 Sensor Circuit Low Voltage Bank 2 Sensor 1 6.10 DTC P0131, P0132, P0133, P0134,
P0137, P0138, P0140, P0151, P0152,
P0153, P0154, P0157, P0158, P0160,
P1133, P1153, P2A01, P2A04
P0152 Heated O2 Sensor Circuit High Voltage Bank 2 Sensor 1 6.10 DTC P0131, P0132, P0133, P0134,
P0137, P0138, P0140, P0151, P0152,
P0153, P0154, P0157, P0158, P0160,
P1133, P1153, P2A01, P2A04
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–80
Page 6C4-2–80
DTC Description Diagnostic Table
P0153 Heated O2 Sensor Slow Response Bank 2 Sensor 1 6.10 DTC P0131, P0132, P0133, P0134,
P0137, P0138, P0140, P0151, P0152,
P0153, P0154, P0157, P0158, P0160,
P1133, P1153, P2A01, P2A04
P0154 Heated O2 Sensor Circuit Insufficient Activity Bank 2
Sensor 1 6.10 DTC P0131, P0132, P0133, P0134,
P0137, P0138, P0140, P0151, P0152,
P0153, P0154, P0157, P0158, P0160,
P1133, P1153, P2A01, P2A04
P0155 Heated O2 Sensor Heater Performance Bank 2 Sensor 1 6.3 DTC P0030, P0036, P0050 P0053,
P0054, P0056, P0059, P0060, P0135,
P0141, P0155, P0161
P0156 Heated O2 Sensor Heated O2 Sensor Circuit
Range/Performance (Bank 2 Sensor 2) 6.10 DTC P0131, P0132, P0133, P0134,
P0137, P0138, P0140, P0151, P0152,
P0153, P0154, P0157, P0158, P0160,
P1133, P1153, P2A01, P2A04
P0157 Heated O2 Sensor Circuit Low Voltage Bank 2 Sensor 2 6.10 DTC P0131, P0132, P0133, P0134,
P0137, P0138, P0140, P0151, P0152,
P0153, P0154, P0157, P0158, P0160,
P1133, P1153, P2A01, P2A04
P0158 Heated O2 Sensor Circuit High Voltage Bank 2 Sensor 2 6.10 DTC P0131, P0132, P0133, P0134,
P0137, P0138, P0140, P0151, P0152,
P0153, P0154, P0157, P0158, P0160,
P1133, P1153, P2A01, P2A04
P0160 Heated O2 Sensor Circuit Insufficient Activity Bank 2
Sensor 2 6.10 DTC P0131, P0132, P0133, P0134,
P0137, P0138, P0140, P0151, P0152,
P0153, P0154, P0157, P0158, P0160,
P1133, P1153, P2A01, P2A04
P0161 Heated O2 Sensor Heater Performance Bank 2 Sensor 2 6.3 DTC P0030, P0036, P0050 P0053,
P0054, P0056, P0059, P0060, P0135,
P0141, P0155, P0161
P0171 Fuel Trim System Lean Bank 1 6.11 DTC P0171, P0172, P0174, P0175
P0172 Fuel Trim System Rich Bank 1 6.11 DTC P0171, P0172, P0174, P0175
P0174 Fuel Trim System Lean Bank 2 6.11 DTC P0171, P0172, P0174, P0175
P0175 Fuel Trim System Rich Bank 2 6.11 DTC P0171, P0172, P0174, P0175
P0201 Injector 1 Control Circuit 6.12 DTC P0201, P0202, P0203, P0204,
P0205, P0206, P0207, P0208
P0202 Injector 2 Control Circuit 6.12 DTC P0201, P0202, P0203, P0204,
P0205, P0206, P0207, P0208
P0203 Injector 3 Control Circuit 6.12 DTC P0201, P0202, P0203, P0204,
P0205, P0206, P0207, P0208
P0204 Injector 4 Control Circuit 6.12 DTC P0201, P0202, P0203, P0204,
P0205, P0206, P0207, P0208
P0205 Injector 5 Control Circuit 6.12 DTC P0201, P0202, P0203, P0204,
P0205, P0206, P0207, P0208
P0206 Injector 6 Control Circuit 6.12 DTC P0201, P0202, P0203, P0204,
P0205, P0206, P0207, P0208
P0207 Injector 7 Control Circuit 6.12 DTC P0201, P0202, P0203, P0204,
P0205, P0206, P0207, P0208
P0208 Injector 8 Control Circuit 6.12 DTC P0201, P0202, P0203, P0204,
P0205, P0206, P0207, P0208
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–81
Page 6C4-2–81
DTC Description Diagnostic Table
P0220 Throttle Position (TP) Sensor 2 Circuit 6.9 DT C P0120, P0121, P0122, P0123,
P0220, P0222, P0223, P1516, P2101,
P2135.
P0222 Throttle Position (TP) Sensor 2 Circuit Low Voltage 6.9 DTC P0120, P0121, P0122, P0123,
P0220, P0222, P0223, P1516, P2101,
P2135.
P0223 Throttle Position (TP) Sensor 2 Circuit High Voltage 6.9 DTC P0120, P0121, P0122, P0123,
P0220, P0222, P0223, P1516, P2101,
P2135.
P0230 Fuel Pump Primary Circuit 6.13 DTC P0230
P0300 Engine Misfire Detected 6.14 DTC P0300, P1380, P1381
P0315 Crankshaft Position System Variation Not Learned 6.15 DTC P0315, P0335, P0336 and P0654
P0324 Knock Sensor (KS) Module Performance 6.16 DTC P0324, P0325, P0326, P0327,
P0328, P0330, P0332, P0333
P0325 Knock Sensor (KS) Circuit Bank 1 6.16 DTC P0324, P0325, P0326, P0327,
P0328, P0330, P0332, P0333
P0326 Knock Sensor (KS) Performance Bank 1 6.16 DTC P0324, P0325, P0326, P0327,
P0328, P0330, P0332, P0333
P0327 Knock Sensor (KS) Circuit Low Frequency Bank 1 6.16 DTC P0324, P0325, P0326, P0327,
P0328, P0330, P0332, P0333
P0328 Knock Sensor (KS) Circuit High Frequency Bank 1 6.16 DTC P0324, P0325, P0326, P0327,
P0328, P0330, P0332, P0333
P0330 Knock Sensor (KS) Circuit Bank 2 6.16 DTC P0324, P0325, P0326, P0327,
P0328, P0330, P0332, P0333
P0332 Knock Sensor (KS) Circuit Low Frequency Bank 2 6.16 DTC P0324, P0325, P0326, P0327,
P0328, P0330, P0332, P0333
P0333 Knock Sensor (KS) Circuit High Frequency Bank 2 6.16 DTC P0324, P0325, P0326, P0327,
P0328, P0330, P0332, P0333
P0335 Crankshaft Position (CKP) Sensor A Circuit 6.15 DTC P0315, P0335, P0336 and P0654
P0336 Crankshaft Position (CKP) Sensor A Performance 6.15 DTC P0315, P0335, P0336 and P0654
P0340 Camshaft Position (CMP) Sensor Circuit Bank 1 Sensor A 6.17 DTC P0340, P0341
P0341 Camshaft Position (CMP) Sensor Performance Bank 1
Sensor A 6.17 DTC P0340, P0341
P0351 Ignition Coil 1 Control Circuit 6.18 DTC P0351, P0352, P0353, P0354,
P0355, P0356, P0357, P0358
P0352 Ignition Coil 2 Control Circuit 6.18 DTC P0351, P0352, P0353, P0354,
P0355, P0356, P0357, P0358
P0353 Ignition Coil 3 Control Circuit 6.18 DTC P0351, P0352, P0353, P0354,
P0355, P0356, P0357, P0358
P0354 Ignition Coil 4 Control Circuit 6.18 DTC P0351, P0352, P0353, P0354,
P0355, P0356, P0357, P0358
P0355 Ignition Coil 5 Control Circuit 6.18 DTC P0351, P0352, P0353, P0354,
P0355, P0356, P0357, P0358
P0356 Ignition Coil 6 Control Circuit 6.18 DTC P0351, P0352, P0353, P0354,
P0355, P0356, P0357, P0358
P0357 Ignition Coil 7 Control Circuit 6.18 DTC P0351, P0352, P0353, P0354,
P0355, P0356, P0357, P0358
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–82
Page 6C4-2–82
DTC Description Diagnostic Table
P0358 Ignition Coil 8 Control Circuit 6.18 DTC P0351, P0352, P0353, P0354,
P0355, P0356, P0357, P0358
P0420 Catalyst System Low Efficiency Bank 1 6.19 DTC P0420 or P0430
P0430 Catalyst System Low Efficiency Bank 2 6.19 DTC P0420 or P0430
P0443 Evaporative Emission (EVAP) Purge Solenoid Control
Circuit 6.20 DTC P0443
P0461 Fuel Level Sensor 1 Performance 6.21 DTC P0461, P0462 and P0463
P0462 Fuel Level Sensor 1 Circuit Low Voltage 6.21 DTC P0461, P0462 and P0463
P0463 Fuel Level Sensor 1 Circuit High Voltage 6.21 DTC P0461, P0462 and P0463
P0480 Cooling Fan 1 Control Circuit 6.22 DTC P0480, P0481
P0481 Cooling Fan 2 Control Circuit 6.22 DTC P0480, P0481
P0502 Vehicle Speed Sensor (VSS) Circuit Low voltage 6.23 DTC P0502
P0506 Idle Air Control (IAC) System - RPM Too Low 6.24 DTC P0506, P0507 P2119
P0507 Idle Air Control (IAC) System - RPM Too High 6.24 DTC P0506, P0507 P2119
P0513 Incorrect Immobilizer Key 6.25 DTC P0513, P0633, P1629, P1632,
P1648, P1677, P1678, P1679
P0522 Engine Oil Pressure (EOP) Sensor/Switch Circuit Low
Voltage 6.26 DTC P0522, P0523
P0523 Engine Oil Pressure (EOP) Sensor/Switch Circuit High
Voltage 6.26 DTC P0522, P0523
P0532 Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit
Low Voltage 6.27 DTC P0532, P0533
P0533 Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit
High Voltage 6.27 DTC P0532, P0533
P0562 System Voltage Low 6.28 DTC P0562, P0563
P0563 System Voltage High 6.28 DTC P0562, P0563
P0575 Cruise Control Input Circuit 6.29 DTC P0575
P0601 Control Module Read Only Memory (ROM) 6.30 DTC P0601, P0602, P0603, P0604,
P0606, P0607, P062F, P1621, P1681,
P2610
P0602 Control Module Not Programmed 6.30 DTC P0601, P0602, P0603, P0604,
P0606, P0607, P062F, P1621, P1681,
P2610
P0603 Control Module Long Term Memory Reset 6.30 DTC P0601, P0602, P0603, P0604,
P0606, P0607, P062F, P1621, P1681,
P2610
P0604 Control Module Random Access Memory (RAM) 6.30 DTC P0601, P0602, P0603, P0604,
P0606, P0607, P062F, P1621, P1681,
P2610
P0606 ECM Processor 6.30 DTC P0601, P0602, P0603, P0604,
P0606, P0607, P062F, P1621, P1681,
P2610
P0607 Control Module Performance 6.30 DTC P0601, P0602, P0603, P0604,
P0606, P0607, P062F, P1621, P1681,
P2610
P0608 Vehicle Speed Output Circuit 1 6.31 DTC P0608
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–83
Page 6C4-2–83
DTC Description Diagnostic Table
P060D Internal Control Module Accelerator Pedal Position
Performance 6.32 DTC P060D, P1680, P2120, P2122,
P2123, P2125, P2127, P2128, P2138
P060E Throttle Position Sensor Circuit 1 and 2 Shorted 6.9 DTC P0120, P0121, P0122, P0123,
P0220, P0222, P0223, P1516, P2101,
P2135.
P0621 Generator 1 L-Terminal Circuit 6.33 DTC P0621, P0622
P0622 Generator 1 F-Terminal Circuit 6.33 DTC P0621, P0622
P062F Engine Internal Control Module EEPROM Error 6.30 DTC P0601, P0602, P0603, P0604,
P0606, P0607, P062F, P1621, P1681,
P2610
P0633 Immobilizer Key Not Programmed - ECM 6.25 DTC P0513, P0633, P1629, P1632,
P1648, P1677, P1678, P1679
P0641 5 Volt Reference 1 Circuit 6.34 DTC P0641 P0651
P0645 Air Conditioning (A/C) Clutch Relay Control Circuit 6.35 DTC P0645
P0651 5 Volt Reference 2 Circuit 6.34 DTC P0641 P0651
P0654 Engine Speed Output Circuit 6.15 DTC P0315, P0335, P0336 and P0654
P0685 Control Module Power Relay Control Circuit 6.36 DTC P0685, P0689, P0690
P0689 Control Module Power Relay Feedback Circuit Low
Voltage 6.36 DTC P0685, P0689, P0690
P0690 Control Module Power Relay Feedback Circuit High
Voltage 6.36 DTC P0685, P0689, P0690
P0700 Transmission Control Module (TCM) Requested MIL
Illumination 6.37 DTC P0700
P0719 Torque Converter/Brake Switch B Circuit Low 6.38 DTC P0719, P0724
P0724 Torque Converter/Brake Switch B Circuit High 6.38 DTC P0719, P0724
P0801 Reverse Inhibit Solenoid Control Switch 6.39 DTC P0801
P0831 Clutch Pedal Switch A Circuit Low Voltage 6.40 DTC P0831 and P0833
P0833 Clutch Pedal Switch B Circuit 6.40 DTC P0831 and P0833
P0851 Park/Neutral Position (PNP) Switch Circuit Low Voltage 6.41 DTC P0851, P0852
P0852 Park/Neutral Position (PNP) Switch Circuit High Voltage 6.41 DTC P0851, P0852
P0856 Traction Control Torque Request Circuit 6.42 DTC P0856
P1101 Intake Air Flow System Performance 6.7 DTC P0112, P0113, P1101
P1133 Heated O2 Sensor Insufficient Switching Bank 1 Sensor 1 6.10 DTC P0131, P0132, P0133, P0134,
P0137, P0138, P0140, P0151, P0152,
P0153, P0154, P0157, P0158, P0160,
P1133, P1153, P2A01, P2A04
P1153 Heated O2 Sensor Insufficient Switching Bank 2 Sensor 1 6.10 DTC P0131, P0132, P0133, P0134,
P0137, P0138, P0140, P0151, P0152,
P0153, P0154, P0157, P0158, P0160,
P1133, P1153, P2A01, P2A04
P1258 Engine Coolant Over temperature – Protection Mode
Active 6.8 DTC P0116, P0117, P0118, P0128,
P1258
P1380 Misfire Detected – Rough Road Date Not Available 6.14 DTC P0300, P1380, P1381
P1381 Misfire Detected – No Communication With Brake Control
Module 6.14 DTC P0300, P1380, P1381
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–84
Page 6C4-2–84
DTC Description Diagnostic Table
P1516 Throttle Actuator Control (TAC) Module T hrottle Actuator
Position Performance 6.9 DTC P0120, P0121, P0122, P0123,
P0220, P0222, P0223, P1516, P2101,
P2135.
P1575 Extended Travel Brake Switch Circuit 6.43 DTC P1575
P1629 Theft Deterrent Fuel or Start Enable Signal Not Received 6.25 DTC P0513, P0633, P1629, P1632,
P1648, P1677, P1678, P1679
P1632 Theft Deterrent Start Disable Signal Received 6.25 DTC P0513, P0633, P1629, P1632,
P1648, P1677, P1678, P1679
P1648 Anti-Theft Device - Wrong Security Code 6.25 DTC P0513, P0633, P1629, P1632,
P1648, P1677, P1678, P1679
P1677 ECM Immobilizer Function Deactivated 6.25 DTC P0513, P0633, P1629, P1632,
P1648, P1677, P1678, P1679
P1678 Immobilizer Powertrain Identification Failed 6.25 DTC P0513, P0633, P1629, P1632,
P1648, P1677, P1678, P1679
P1679 Immobilizer Environment Identification Failed 6.25 DTC P0513, P0633, P1629, P1632,
P1648, P1677, P1678, P1679
P1682 Ignition 1 Switch Circuit 2 6.44 DTC P1682
P1689 Traction Control Delivered Torque Signal Output Circuit
Malfunction 6.9 DTC P0120, P0121, P0122, P0123,
P0220, P0222, P0223, P1516, P2101,
P2135.
P2101 Control Module Throttle Actuator Position Performance 6.9 DTC P0120, P0121, P0122, P0123,
P0220, P0222, P0223, P1516, P2101,
P2135.
P2119 Throttle Valve Close Adaptation Malfunction 6.24 DTC P0506, P0507 P2119
P2120 Accelerator Pedal Position (APP) Sensor 1 Circuit 6.32 DTC P060D, P1680, P2120, P2122,
P2123, P2125, P2127, P2128, P2138
P2122 Accelerator Pedal Position (APP) Sensor 1 Circuit Low
Voltage 6.32 DTC P060D, P1680, P2120, P2122,
P2123, P2125, P2127, P2128, P2138
P2123 Accelerator Pedal Position (APP) Sensor 1 Circuit High
Voltage 6.32 DTC P060D, P1680, P2120, P2122,
P2123, P2125, P2127, P2128, P2138
P2125 Accelerator Pedal Position (APP) Sensor 2 Circuit 6.32 DTC P060D, P1680, P2120, P2122,
P2123, P2125, P2127, P2128, P2138
P2127 Accelerator Pedal Position (APP) Sensor 2 Circuit Low
Voltage 6.32 DTC P060D, P1680, P2120, P2122,
P2123, P2125, P2127, P2128, P2138
P2128 Accelerator Pedal Position (APP) Sensor 2 Circuit High
Voltage 6.32 DTC P060D, P1680, P2120, P2122,
P2123, P2125, P2127, P2128, P2138
P2135 Throttle Position (TP) Sensor 1-2 Correlation 6.9 DTC P0120, P0121, P0122, P0123,
P0220, P0222, P0223, P1516, P2101,
P2135.
P2138 Accelerator Pedal Position (APP) Sensor 1-2 Correlation 6.32 DTC P060D, P1680, P2120, P2122,
P2123, P2125, P2127, P2128, P2138
P2176 Minimum Throttle Position Not Learned 6.9 DTC P0120, P0121, P0122, P0123,
P0220, P0222, P0223, P1516, P2101,
P2135.
P2544 Torque Management Request Input Signal A 6.45 DTC P2544
P2610 ECM Internal Engine Off Timer Performance 6.30 DTC P0601, P0602, P0603, P0604,
P0606, P0607, P062F, P1621, P1681,
P2610
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–85
Page 6C4-2–85
DTC Description Diagnostic Table
P2A01 Heated O2 Sensor Circuit Range/Performance Bank 1
Sensor 2 6.10 DTC P0131, P0132, P0133, P0134,
P0137, P0138, P0140, P0151, P0152,
P0153, P0154, P0157, P0158, P0160,
P1133, P1153, P2A01, P2A04
P2A04 Heated O2 Sensor Circuit Range/Performance Bank 2
Sensor 2 6.10 DTC P0131, P0132, P0133, P0134,
P0137, P0138, P0140, P0151, P0152,
P0153, P0154, P0157, P0158, P0160,
P1133, P1153, P2A01, P2A04
U0073 Control Module Communication Bus Off 6.46 DTC U0073
U0101 Lost Communication with TCM 6.47 DTC U0101, U0121
U0121 Lost Communication With Anti-lock Brake System (ABS)
Control Module 6.47 DTC U0101, U0121
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–86
Page 6C4-2–86
6.2 DTC P0016
DTC Descriptor
This diagnostic procedure supports the following DTC:
• DTC P0016 Crankshaft Position (CKP)-Camshaft Position (CMP) Correlation Bank 1 Sensor A
Circuit Description
The Engine control relay applies ignition positive battery voltage to the camshaft position sensor (CMP) through the
ignition voltage circuit.
The ECM compares the camshaft position to the crankshaft position to detect CMP system malfunction. A CKP / CMP
sensor correlation DTC sets if the ECM detects a deviation between the target position of the camshaft and the
crankshaft position.
Conditions for Running the DTC
DTC P0016
The engine is running
Conditions for Setting the DTC
The ECM detects a signal from the CMP sensor signal circuit and the sensor range is not within the predetermined
parameter or when the CMP sensor does not correlate with the crankshaft position.
Conditions for Clearing the DTC
The CKP / CMP sensor correlation DTCs are Type B DTCs. Refer to 1.5 Diagnostic Trouble Codes for action taken
when Type B DTCs set and conditions for clearing Type B DTCs
Additional Information
• Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the CMP system operation.
• Inspect the engine for recent engine mechanical repairs. Incorrect camshaft, camshaft actuator or timing chain
installation will trigger this DTC.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Since fault condition in a wiring connector may trigger the DTC, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to Section 12P
Wiring Diagrams for information on electrical fault diagnosis.
• To assist diagnosis, refer to 2 Wiring Diagrams and Connector Charts.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
3 A fault condition in any of the listed sensors will trigger these DTCs.
5 Incorrect camshaft, camshaft actuator or timing chain installation will trigger these DTCs
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–87
Page 6C4-2–87
DTC P0016
Step Action Values Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch off the ignition for 30 seconds.
2 Start the engine.
3 Allow the engine to reach the normal operating
temperature.
4 Increase the engine speed to 2,000 rpm for 10
seconds.
5 Using Tech 2, select the DTC display function.
Does DTC P0016 fail this ignition cycle?
Go to Step 3
Refer to Additional
Information in this
section
3 Are DTCs relating to the following DTCs also set:
• CMP sensor circuit
• CKP sensor circuit
Refer to the
appropriate DTC
table Go to Step 4
4 Inspect the engine for the following fault conditions. Refer
to 6A4 Engine Mechanical – GEN IV V8:
• incorrect installation of the CMP sensor,
• incorrect installation of the CKP sensor,
• timing chain tensioner fault condition,
• incorrectly installed timing chain,
• excessive play in the timing chain, and
• timing chain that jumped teeth.
Was any fault found and rectified?
Go to Step 5
Refer to Additional
Information in this
section
5 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC.
Does any of the crankshaft / camshaft position
correlation DTCs fail this ignition cycle?
Go to Step 2 Go to Step 6
6 Using Tech 2, select the DTC display function.
Are there any DTCs displayed?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–88
Page 6C4-2–88
6.3 DTC P0030, P0036, P0050 P0053, P0054,
P0056, P0059, P0060, P0135, P0141,
P0155, P0161
DTC Description
This diagnostic procedure supports the following DTCs:
• DTC P0030 – Heated O2 Sensor Heater Control Circuit Bank 1 Sensor 1
• DTC P0036 – Heated O2 Sensor Heater Control Circuit Bank 1 Sensor 2
• DTC P0050 – Heated O2 Sensor Heater Control Circuit Bank 2 Sensor 1
• DTC P0053 – Heated O2 Sensor Heater Resistance Bank 1 Sensor 1
• DTC P0054 – Heated O2 Sensor Heater Resistance Bank 1 Sensor 2
• DTC P0056 – Heated O2 Sensor Heater Control Circuit Bank 2 Sensor 2
• DTC P0059 – Heated O2 Sensor Heater Resistance Bank 2 Sensor 1
• DTC P0060 – Heated O2 Sensor Heater Resistance Bank 2 Sensor 2
• DTC P0135 – Heated O2 Sensor Heater Performance Bank 1 Sensor 1
• DTC P0141 – Heated O2 Sensor Heater Performance Bank 1 Sensor 2
• DTC P0155 – Heated O2 Sensor Heater Performance Bank 2 Sensor 1
• DTC P0161 – Heated O2 Sensor Heater Performance Bank 2 Sensor 2
Circuit Description
The engine control relay applies positive voltage to the heater ignition voltage circuits of the Heated O2 Sensor. The
ECM applies a pulse width modulated (PWM) ground to the heater control circuit of the Heated O2 Sensor through a
device within the ECM called a driver, to control the Heated O2 Sensor rate of heating.
The driver has a feedback circuit that is pulled-up when the voltage is approximately 3.3 V. The ECM monitors the Driver
feedback circuit to determine if the control circuit is open, shorted to ground or shorted to a positive voltage.
A Heated O2 Sensor heater control circuit DTC sets if the ECM detects a high resistance, open circuit, short to ground or
short to voltage fault condition in the Heated O2 Sensor heater control circuit.
To aid diagnosis, refer to 2 Wiring Diagrams and Connector Charts for the system wiring diagram and connector charts.
Additional Information
• Refer to Section 6C4-1 Engine Management –GEN IV V8– General Information for details of the Heated O2 Sensor
system operation.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• A faulty Heated O2 Sensor heater element may cause an open heater circuit condition. T his fault may be
intermittent or only show up after the sensor has operated for a period.
• Inspect the Heated O2 Sensor wiring harness for contact with the exhaust system.
• The front and the rear Heated O2 Sensor sensors have a separate fuse connection. If both front or both the rear
DTCs are set, the appropriate Heated O2 Sensor ignition voltage circuit may be open.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–89
Page 6C4-2–89
Conditions for Running the DTC
Runs continuously once the following conditions are met:
• The ignition voltage is 10.0 – 16.0 V.
• Engine speed is greater than 80 RPM.
Conditions for Setting the DTC
DTC P0030, P0036, P0050 or P0056
These DTC'S check the heater output driver circuit for electrical integrity
DTC P0053, P0054, P0059, P0060
Out of range resistance: detects an oxygen sensor heater having an incorrect or out of range resistance value.
DTC P0135, P0141, P0155, P0161
Current monitor: detects a malfunctioning Heated O2 Sensor heater circuit by monitoring the current through the circuit
and out of range resistance: detects an oxygen sensor heater having an incorrect or out of range resistance value.
Conditions for Clearing the DTC
The Heated O2 Sensor heater control circuit DTCs are Type B DTCs. Refer to 1.5 Diagnostic T r ouble Codes for action
taken when Type B DTC sets and conditions for clearing Type B DTCs.
Test Description
The following number refers to the step number in the diagnostic table:
4 The ECM monitors the Driver feedback circuit to determine if the heater control circuit is open, shorted to ground or
shorted to a positive voltage. If the voltage is outside the specified range, there is a fault condition with the heater
control circuit.
DTC P0030, P0036, P0050, P0053, P0054, P0056, P0059, P0060, P0135, P0141, P0155, P0161
Diagnostic Table
Step Action Values Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch off the ignition for 30 seconds.
2 Start the engine.
3 Allow the engine to run at idle speed for at least 30
seconds.
4 Increase the engine speed to 2,000 RPM. for 10
seconds.
5 Using Tech 2, select the DTC display function.
Does DTC P0030, P0036, P0050, P0053, P0054, P0056,
P0059, P0060, P0135, P0141, P0155 or P0161 fail this
ignition cycle? Go to Step 3
Refer to Additional
Information in this
section
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–90
Page 6C4-2–90
Step Action Values Yes No
3 1 Disconnect the appropriate Heated O2 Sensor
wiring connector.
2 Switch on the ignition with the engine not running.
3 Connect a test lamp between the Heated O2
Sensor heater ignition voltage circuit and the ECM
housing.
Does the test lamp illuminate? Go to Step 4 Go to Step 5
4 Using a digital multimeter, measure the voltage between
the Heated O2 Sensor heater control circuit and a good
ground.
Does the multimeter display between:-
OS1 sensor
4.6-5.2V?
OS2 sensor
2.8-4.2V? Go to Step 7 Go to Step 6
5 NOTE
The Heated O2 Sensor ignition voltage circuit
is shared with other sensors. Ensure that all
circuits and components that share this
ignition voltage circuit are tested for a short to
ground.
Repair the high resistance open circuit or short to ground
fault condition in the Heated O2 Sensor heater ignition
voltage circuit. Refer to 12P Wiring Diagrams for
information on electrical wiring repair procedures.
Was the repair completed? Go to Step 9 —
6 Test the Heated O2 Sensor heater control circuit for a
high resistance, open circuit, short to ground or short to
voltage fault condition. Refer to 12P Wiring Diagrams for
information on electrical fault diagnosis.
Was any fault found and rectified? Go to Step 9 Go to Step 8
7 Replace the appropriate Heated O2 Sensor. Refer to
6C4-3 Engine Management – GEN IV V8– Service
Operations.
Was the repair completed? Go to Step 9 —
8 Replace the ECM. Refer to 6C4-3 Engine Management –
GEN IV V8 – Service Operations.
Was the repair completed? Go to Step 9 —
9 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC.
Does any of the Heated O2 Sensor heater control circuit
DTCs fail this ignition cycle? Go to Step 2 Go to Step 10
10 Using Tech 2, select the DTC display function.
Are there any DTCs displayed
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–91
Page 6C4-2–91
6.4 DTC P0068
DTC Descriptor
This diagnostic procedure supports the following DTC:
• DTC P0068 - MAP/MAF - Throttle Position Correlation
Circuit Description
The Engine Control Module (ECM), uses the Throttle Position Sensors (TPS), Intake Air Temperature (IAT, and Engine
RPM in order to calculate a predicted mass air flow rate. The ECM compares the predicted mass air flow value to the
actual Mass Air Flow value established by the Mass Air Flow (MAF) sensor and the speed density calculation, in order to
verify the correct throttle operation.
Conditions for Running the DTC
DTC P0068
• MAP based airflow is greater than 150 mg/cyl and MAF based airflow is greater than 150 mg/cyl
• The engine is running
• The engine speed is greater than 500 RPM
• There is no ECM processor, throttle actuation, TACM processor, ECM-TACM serial data or both TPS DTCs set
Conditions for Setting the DTC
DTC P0068
The ECM detects that the actual airflow (MAF) does not match the estimated airflow as established by the TPS
Conditions for Clearing the DTC
DTC P0068 is a Type A DTC. Refer to 1.5 Diagnostic Tr ouble Codes, for action taken when a Type A DTC sets and
conditions for clearing a Type A DTC
Additional Information
Refer to Section 6C4-1 Engine Management GEN IV V8 – General Information for details of the Throttle Actuator Control
system operation.
Test Conditions
The Following numbers refer to the step numbers in the diagnostic chart
Disconnect the throttle body wi ring connector
before inserting fingers into the throttle bore.
Unexpected movement of the throttle blade
could cause personal injury
3 Physically and visually inspect the throttle body assembly, and correct any problems found. Manually move the
throttle plate from the closed to wide open throttle (WOT). Excessive force should not be required to move the
throttle plate which must move smoothly through full range and return to a slightly open position on its own.
5 When the ECM detects a condition within the TAC system, more than one TAC system related DTC may be set.
This is due to the redundant tests that run continuously on this system. Locating and repairing one individual
condition may correct more than one DTC. Disconnecting components during testing may set additional DTCs
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–92
Page 6C4-2–92
DTC P0068
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Observe the Freeze Frame / Failure Recording for this DTC.
2 Switch Off the ignition for 30 seconds.
3 Operate the vehicle within the conditions for running the DTC or
within the conditions in the Freeze Frame / Failure Records.
4 Using Tech 2, select:
Engine/Diagnostic Trouble Codes / Read DTC Information.
Are any TPS, MAF, MAP, IAT or TAC DTCs set?
Go to the
appropriate DTC
Table Go to Step 3
3
Disconnect the throttle body wiring connector
before inserting fingers into the throttle bore.
Unexpected movement of the throttle blade could
cause personal injury
NOTE
If any of the conditions listed below exist, replace the
throttle body assembly, refer to 6C4-3 Engine
Management GEN IV V8 – Service Operations.
Inspect the throttle body for the following conditions:
• A loose or damaged throttle blade
• A cracked or bent throttle shaft
• Drive mechanism damage
Was any fault found and rectified? Go to Step 4
Refer to 6.4 DTC
P0068, Conditions for
Running the DTC
4 1 Using Tech 2, clear the DTCs
2 Switch Off the ignition for 30 seconds.
3 Start the engine
4 Operate the vehicle within the conditions for running the DTC or
within the conditions in the Freeze Frame / Failure Records
Did DTC P0068 fail this ignition cycle? Go to Step 2 Go to Step 5
5 Using Tech 2, select the DTC display function.
Are there any DTCs displayed?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–93
Page 6C4-2–93
6.5 DTC P0101, P0102, P0103, P1101
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0101 – Mass Air Flow Sensor Circuit Range / Performance
• DTC P0102 – Mass Air Flow Sensor Voltage Low
• DTC P0103 – Mass Air Flow Sensor Voltage High
• DTC P1101 – Inlet Airflow System Performance
Circuit Description
The ignition control relay applies ignition positive voltage to the mass airflow (MAF) sensor. The ECM applies 5 V
reference voltage and ground through the low reference circuit.
A heater resistor on the MAF sensor heats a micro-mechanical sensor diaphragm at a constant temperature. Two
temperature dependent resistors positioned at each side of the heater resistor measure the intake air temperature:
• The first is located at a position before the intake air passes through the heater resistor. This temperature
dependent resistor measures the temperature of the intake air before the air is heated.
• The second is located at a position after the intake air has passed through the heater resistor. This sensor
measures the temperature of the intake air after the air is heated.
The evaluation circuit on the MAF sensor converts the difference in the resistance value of these two temperature
dependent resistors into an analogue signal voltage. The ECM monitors this signal voltage through the MAF sensor
signal to calculate the engine intake air mass.
A MAF sensor circuit DTC sets if the ECM detects the actual MAF sensor signal is not within the predetermined range of
the calculated MAF sensor value.
Conditions for Running the DTC
DTC P0101
Runs continuously once the following conditions are met:
• DTCs P0121, P0122, P0123, P0222 and P0223 ran and passed.
• The engine is running.
• The ignition voltage is 10.0 – 16.0 V.
• The MAF sensor signal is -11.6 to +295 grams per second.
• The ECM detects greater than 150 crankshaft revolutions.
DTC P0102
Runs continuously once the following conditions are met:
• DTCs P0121, P0122, P0123, P0222 and P0223 ran and passed.
• The engine is running.
• The ignition voltage is 10.0 – 16.0 V.
DTC P0103
Runs continuously once the following conditions are met:
• DTCs P0121, P0122, P0123, P0222 and P0223 ran and passed.
• The engine is running at speed greater than 320 rpm
• The ignition voltage is 10.0 – 16.0 V.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–94
Page 6C4-2–94
DTC P1101
Runs continuously once the following conditions are met
• Engine speed between 550 and 6800rpm
• engine coolant between 70 and 125 deg C
• no MAP sensor MAF sensor Crank sensor ECT sensor or IAT sensor codes present
• codes P0401, P0405 and P01404 are not active
Conditions for Setting the DTC
DTC P0101
The ECM detects the MAF sensor signal is not within the predetermined range of the calculated MAF value for 2
seconds.
DTC P0102
The ECM detects the MAF sensor signal is less than -11.7 grams per second.
DTC P0103
The ECM detects the MAF sensor signal is greater than 294 grams per second.
DTC P1101
The ECM detects flaws with all inlet airflow sensors suggesting a major inlet flow problem
Additional Information
• The MAF sensor circuit DTCs is a Type B DTC. Refer to 1.5 Diagnostic Trouble Codes for action taken when a
Type B DTC sets and conditions for clearing Type B DTC.
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the MAF sensor
operation.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Inspect the MAF sensor for an incorrectly routed harness or if the harness is too close to the following:
− ignition coil,
− solenoids,
− relays, and
− motors.
• A low minimum air rate may cause this DTC to set during deceleration. Inspect for the following conditions:
− a plugged or a collapsed intake air duct, or a dirty air filter element,
− objects that block the MAF sensor air inlet screen, and
− sticking or dirty throttle plate or throttle bore.
• Any un-metered air that enters the engine may cause this DTC to set. Inspect for vacuum leaks in the following:
− intake manifold,
− throttle body,
− barometric pressure (BARO) sensor seal,
− brake booster system,
− air induction system, and
− crankcase ventilation system.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–95
Page 6C4-2–95
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• To assist diagnosis, refer to 2 Wiring Diagrams and Connector Charts for the system wiring diagram and connector
charts.
DTC P0101 to P0103 and P1101 Diagnostic Table
Step Action Values Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for
running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P0101, P0102, P0103 or P1101 fail this
ignition cycle? Go to Step 3
Refer to Additional
Information in this
Section
3 Inspect for the following fault conditions:
• engine vacuum leak,
• air leak in the intake air duct between the MAF
sensor and the throttle body,
• plugged or collapsed intake air duct,
• objects that block the MAF sensor inlet screen,
• restricted air filter element,
• restricted throttle plate or carbon build-up around
the throttle plate,
• unseated engine oil dipstick,
• loose or missing engine oil cap, and
• over filled crankcase.
Was any fault found and rectified? Go to Step 14 Go to Step 4
4 1 Disconnect the MAF sensor wiring connector.
2 Connect a test lamp between the MAF sensor
ignition voltage circuit and the ECM housing.
3 Switch on the ignition with the engine not
running.
Does the test lamp illuminate? Go to Step 5 Go to Step 11
5 1 Switch on the ignition with the engine not
running.
2 Using a digital multimeter, measure the voltage
between the MAF sensor 5 V reference circuit
and the ECM housing.
Does the multimeter display between 4.8 – 5.2 V? Go to Step 6 Go to Step 8
6 1 Switch off the ignition.
2 Disconnect the ECM wiring connector.
3 Using a digital multimeter, measure the
resistance on the signal circuit.
Does the multimeter display less than
5 ohms Go to Step 7 Go to Step 9
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–96
Page 6C4-2–96
Step Action Values Yes No
7 1 Switch off the ignition.
2 Remove ECM Fuse 29 from the engine
compartment fuse and relay panel assembly.
3 Using a digital multimeter, measure the
resistance between the MAF sensor low
reference circuit and the ECM housing.
NOTE
Install ECM Fuse 29 to the engine
compartment fuse and relay panel
assembly after completing the test.
Does the multimeter display less than 5 Ω? Go to Step 12 Go to Step 10
8 Test the MAF sensor 5 V reference circuit for a high
resistance, open circuit or short to voltage fault
condition. Refer to 12P Wiring Diagrams for
information on electrical fault diagnosis.
NOTE
The MAF sensor shares the 5 V reference
circuit with other sensors. A fault condition
in the 5 V reference circuit will trigger DT Cs
on sensors that share this circuit.
Was any fault found and rectified? Go to Step 14 Go to Step 13
9 Test the MAF sensor signal circuit for a high
resistance, open circuit, short to ground or short to
voltage fault condition. Refer to 12P Wiring Diagrams
for information on electrical fault diagnosis.
Was any fault found and rectified? Go to Step 14 Go to Step 13
10 Test the MAF sensor low reference circuit for a high
resistance or an open circuit fault condition. Refer to
12P Wiring Diagrams for information on electrical fault
diagnosis.
Was any fault found and rectified? Go to Step 14 Go to Step 13
11 Repair the high resistance or open circuit fault
condition in the MAF sensor circuit ignition voltage.
Refer to 12P Wiring Diagrams for information on
electrical wiring repair procedures.
Was the repair completed? Go to Step 14 —
12 Replace the MAF sensor. Refer to 6C4-3 Engine
Management – GEN IV V8 – Service Operations.
Was the repair completed? Go to Step 14 —
13 Replace the ECM. Refer to 6C4-3 Engine
Management – GEN IV V8 – Service Operations.
Was the repair completed? Go to Step 14 —
14 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC.
Does any of the MAF Sensor Circuit DTCs fail this
ignition cycle? Go to Step 2 Go to Step 15
15 Using Tech 2, select the DTC display function.
Are there any DTCs displayed?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–97
Page 6C4-2–97
6.6 DTC P0106, P0107, P0108
DTC Description
This diagnostic procedure covers the following DTCs:
• DTC P0106 – Manifold Absolute Pressure Sensor Circuit Range / Performance
• DTC P0107 – Manifold Absolute Pressure Sensor Circuit Low Voltage
• DTC P0108 – Manifold Absolute Pressure Sensor Circuit High Voltage
Circuit Description
The Manifold Absolute Pressure (MAP) sensor responds to pressure changes in the intake manifold. The pressure
changes in the intake manifold occur based on engine load. The Engine Control Module (ECM) supplies 5 volts to the
MAP sensor on the 5 volt reference circuit, and a ground on the low reference circuit. The MAP sensor provides a signal
to the ECM on the signal circuit.
The MAP Sensor contains a diaphragm which changes the resistance based on pressure. When the manifold pressure is
low (high vacuum), the sensor output voltage is low. When the manifold pressure is high (low vacuum), the sensor output
voltage is high. The MAP Sensor voltage can range from 1.0 – 1.5 volts at idle (high vacuum) to 4.0 – 4.9 volts at wide
open throttle (low vacuum).
The ECM monitors the MAP sensor signal for voltage outside the normal range. The ECM calculates a predicted value
for the MAP sensor based on the throttle position and the engine speed. The ECM then compares the predicted value to
the actual MAP sensor signal. A MAP sensor DTC will set if the MAP sensor signal is not within the predicted range.
Conditions for Running the DTC
DTC P0106
• The engine is running.
• There are no MAP sensor, TP sensor, MAF sensor, EVAP, or TAC DTCs set.
• Traction control is not active.
• Change in the engine speed is less than 125 RPM in one second.
• The power steering is stable for one second.
• The A/C compressor clutch is steady for one second.
• The clutch switch state does not change for one second.
• The brake switch state does not change for one second.
• Throttle position does not change to wide open for one second.
• The idle air does change more than 10 g/s in one second.
• The engine speed is between 500 and 5000 RPM.
DTC P0107
• The engine is running.
• There are no TPS or 5 volt reference circuit DTCs set.
• The throttle position is greater than 0% when the engine speed is less than 800 RPM, or the throttle position is
greater than 12.5% when the engine speed is greater than 800 RPM.
DTC P0108
• The engine is running.
• There are no TPS DTCs set.
• The throttle position is less than 1% when the engine speed is less than 1200 RPM, or the throttle position is less
than 20% when the engine speed is greater than 1200 RPM.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–98
Page 6C4-2–98
Conditions for Setting the DTC
DTC P0106
The ECM detects that the actual MAP signal does not match the predicted MAP signal as established by the TPS and
engine RPM.
DTC P0107
The ECM detects that the MAP sensor signal is less than 0.04 V.
DTC P0108
The ECM detects that the MAP sensor signal is greater than 4.89 V.
Conditions for Clearing DTCs
• DTCs P0106, P0107, and P0108 are Type B DTCs. Refer to 1.5 Diagnostic Trouble Codes for action taken when a
Type B DTC sets and conditions for clearing a Type B DTC.
Additional Information
• Refer to Section 6C4-1 Engine Management GEN IV V8 – General Information for details of the MAP sensor
operation.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Inspect the MAP sensor for a mis-routed harness or if the harness is too close to the following:
• ignition coil,
• solenoids,
• relays
• motors.
• Inspect for the following conditions:
• Restrictions in the MAP sensor vacuum source.
• Inspect for vacuum leaks in the following:
• intake manifold,
• throttle body,
• MAP sensor seal,
• EVAP canister purge valve seal,
• brake booster system,
• air induction system
• crankcase ventilation system.
• Since a fault condition in a wiring connector may trigger DTCs, always test the sensor connectors related to this
diagnostic procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• Refer to 2 Wiring Diagrams and Connector Charts to aid in the diagnosis procedures.
Test Description
The following numbers refer to the step numbers in the diagnostic chart:
3 Restricted intake air flow or engine vacuum leaks may trigger these DTCs.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–99
Page 6C4-2–99
Diagnostic Table for DTCs P0106, P0107 and P0108
Step Action Value(s) Yes No
1 Has the Diagnostic System Check been performed?
– Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Observe the Freeze Frame / Failure Record for
this DTC.
2 Switch off the ignition for 30 seconds.
3 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
4 Using Tech 2 select:
Engine / Diagnostic Trouble Codes / Read DTC
Information.
Does DTC P0106, P0107, or P0108, fail this ignition
cycle? –
Go to Step 3
Refer to Additional
Information in this
section.
3 Inspect for the following fault conditions:
• engine vacuum leak,
• plugged or collapsed intake air duct, including the
MAF sensor,
• restricted air filter element,
• restricted throttle plate or carbon build-up around
the throttle plate,
• unseated engine oil dipstick,
• loose or missing engine oil cap, and
• over filled crankcase.
Was any fault found and rectified? – Go to Step 12 Go to Step 4
4 1 Switch off the ignition.
2 Disconnect the MAP sensor electrical connector.
3 Turn on the ignition, with the engine not running.
4 Using a digital multimeter, measure the voltage
between the MAP sensor 5 volts reference circuit
and the ECM housing.
Is the voltage within the specified range? 4.8 – 5.2 V Go to Step 5 Go to Step 7
5 1 Switch off the ignition.
2 Disconnect the ECM wiring connector.
3 Using a digital multimeter, measure the resistance
on the signal circuit.
Does the multimeter display less than
5 ohms Go to Step 6 Go to Step 8
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–100
Page 6C4-2–100
Step Action Value(s) Yes No
6 1 Switch off the ignition.
2 Remove ECM Fuse 29 from the engine
compartment fuse and relay panel assembly.
3 Using a digital multimeter, measure the resistance
between the MAP sensor low reference circuit and
the ECM housing.
NOTE
Install ECM Fuse 29 to the engine
compartment fuse and relay panel assembly
after completing the test.
Is the resistance less than the specified value? 5 Ω Go to Step 10 Go to Step 9
7 Test the MAP sensor 5 volts reference circuit for a high
resistance, open circuit, short to ground, or short to
voltage fault condition. Refer to 12P Wiring Diagrams
for information on electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 12 Go to Step 11
8 Test the MAP sensor signal circuit for a high resistance,
open circuit; short to ground or short to voltage fault
condition. Refer to 12P Wiring Diagrams for information
on electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 12 Go to Step 10
9 Test the MAP sensor low reference circuit for a high
resistance or an open circuit fault condition. Refer to
12P Wiring Diagrams for information on electrical fault
diagnosis.
Was any fault found and rectified? – Go to Step 12 Go to Step 11
10 Replace the MAP sensor. Refer to 6C4-3 Engine
Management – GEN IV – Service Operations.
Was the repair completed? – Go to Step 12 –
11 Replace the ECM. Refer to 6C4-3 Engine
Management – GEN IV V8 – Service Operations.
Was the repair completed? – Go to Step 12 –
12 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
Do any MAP sensor circuit DTCs fail this ignition cycle? – Go to Step 2 Go to Step 13
13 Using Tech 2, select the DTC display function.
Are there any DTCs displayed? –
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–101
Page 6C4-2–101
6.7 DTC P0112, P0113, P1101
DTC Description
This diagnostic procedure covers the following DTCs:
• DTC P0112 – Intake Air Temperature Circuit Low Voltage
• DTC P0113 – Intake Air Temperature Circuit High Voltage
• DTC P1101.-.Intake Air System Performance
Circuit Description
The ECM applies a reference 5 volts to the Intake Air Temperature (IAT) sensor signal circuit and ground connection.
The IAT sensor is a variable resistor that measures the engine intake air temperature.
• Increased intake air temperature results in the following:
• the IAT sensor resistance decreases,
• increased IAT sensor signal circuit pull-down rate to ground, and
• the IAT sensor signal voltage is decreased.
• Decreased intake air temperature results in the following:
• the IAT sensor resistance increases,
• decreased IAT sensor signal circuit pull-down rate to ground, and
• the IAT sensor signal voltage is increased.
An Intake Air Temperature (IAT) Sensor Circuit DT C sets if the ECM detects that the intake air temperature is outside the
specified range.
Conditions for Running the DTC
DTC P0112
• No Vehicle Speed sensor DTCs are set.
• The engine run time is greater than 45 seconds.
• The vehicle speed is more than 40 km/h.
• No active ECT DTCs are set
• The Engine Coolant temperature is below 125°C.
DTC P0113
• No Vehicle Speed sensor, Mass Air Flow sensor, or Engine Coolant Temperature sensor DTC(s) are set.
• The engine run time is greater than 120 seconds.
• The vehicle speed is less than 11 km/h.
• The Engine Coolant temperature is greater than 60°C.
• Mass Air Flow is less than 15 g/s.
Conditions for Setting the DTC
DTC P0112
The IAT sensor signal is less than 0.244 V.
DTC P0113
The IAT sensor signal is greater than 4.95 V.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–102
Page 6C4-2–102
Conditions for Clearing the DTCs
DTCs P0112 and P0113 are Type B DTCs. Refer to 1.5 Diagnostic T r ouble Codes for action taken when a Type B DTC
sets and conditions for clearing Type B DTC.
Additional Information
• Refer to Section 6C4-1 Engine Management GEN IV V8 – General Information for details of the IAT Sensor
operation.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Test the IAT sensor using the IAT Temperature vs. Resistance in Section 6C4-3 Engine Management GEN IV V8 –
Service Operations. If the engine has been switched off for an extended period, overnight for example, the IAT
sensor should display within 3°C of the ECT sensor values.
• Since a fault condition in a wiring connector may trigger DTCs, always test the sensor connectors related to this
diagnostic procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• Refer to 2 Wiring Diagrams and Connector Charts to aid in the diagnosis procedures.
Test Description
The following numbers refer to the step numbers in the diagnostic chart:
3 Tests the signal circuit of the IAT sensor.
4 Measures the integrity of the IAT sensor low reference circuit. Removal of the ECM Fuse 29 enables the ECM to
power down completely prior to the test procedure.
Diagnostic Table for the Intake Air Temperature Sensor Circuit DTCs
Step Action Value(s) Yes No
1 Was the Diagnostic Systems Check performed?
– Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Observe the Freeze Frame / Failure Record for
this DTC.
2 Switch off the ignition for 30 seconds.
3 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
4 Using Tech 2 select:
Engine / Diagnostic Trouble Codes / Read DTC
Information.
Does DTC P0112 or P0113 fail this ignition cycle? – Go to Step 3
Refer to Additional
Information in this
section
3 1 Switch off the ignition.
2 Disconnect the IAT sensor wiring connector.
3 Switch on the ignition with the engine not running.
4 Using a digital multimeter, measure the voltage
between the IAT sensor signal circuit and the
ECM housing.
Is the voltage within the specified range? 4.8 – 5.2 V Go to Step 4 Go to Step 5
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–103
Page 6C4-2–103
Step Action Value(s) Yes No
4 1 Switch off the ignition.
2 Remove ECM Fuse 29 from the engine
compartment fuse and relay panel assembly.
3 Using a digital multimeter, measure the resistance
between the IAT sensor low reference circuit and
the ECM housing.
NOTE
Install the ECM Fuse 29 to the engine
compartment fuse and relay panel assembly
after completing this test.
Is the resistance less than the specified value? 5 Ω Go to Step 7 Go to Step 6
5 Test the IAT sensor signal circuit for a short to voltage,
an open circuit or high resistance fault condition. Refer
to 12P Wiring Diagrams for information on electrical
fault diagnosis.
Was any fault found and rectified? – Go to Step 9 Go to Step 8
6 Test the IAT sensor low reference circuit for a short to
voltage, an open circuit or high resistance fault
condition. Refer to 12P Wiring Diagrams for information
on electrical fault diagnosis.
NOTE
The IAT sensor shares the low reference
circuit with other sensors. A fault condition in
the low reference circuit may trigger DTCs
on sensors that share this circuit. Refer to
12P Wiring Diagrams.
Was any fault found and rectified? – Go to Step 9 Go to Step 8
7 Replace the MAF / IAT sensor assembly. Refer to
6C4-3 Engine Management GEN IV V8 – Service
Operations.
Was the repair completed? – Go to Step 9 –
8 Replace the ECM. Refer to 6C4-3 Engine Management
GEN IV V8 – Service Operations.
Was the repair completed? – Go to Step 9 –
9 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
Do any IAT sensor DTCs fail this ignition cycle? – Go to Step 2 Go to Step 10
10 Using Tech 2, select the DTC display function.
Are there any DTCs displayed? –
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–104
Page 6C4-2–104
6.8 DTC P0116, P0117, P0118, P0128, P1258
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0116 – Engine Coolant Temperature Sensor Circuit Range / Performance
• DTC P0117 – Engine Coolant Temperature Sensor Circuit Low Voltage
• DTC P0118 – Engine Coolant Temperature Sensor Circuit High Voltage
• DTC P0128 – Engine Coolant below Thermostat Regulating Temperature
• DTC P1258 – Engine Coolant Over Temperature - Protection Mode Active
Circuit Description
The ECM applies a reference 5 V to the engine coolant temperature (ECT) sensor signal circuit and ground through the
low reference circuit. The ECT sensor is a variable resistor that measures the temperature of the engine coolant.
• Increased temperature in the engine coolant decreases the resistance value of the ECT sensor. This increases the
ECT sensor pull-down rate to ground. Therefore, the higher the engine coolant, the lower the signal voltage output
of the ECT sensor.
• Decreased temperature in the engine coolant increases the resistance value of the ECT sensor. This reduces the
ECT sensor pull-down rate to ground. Therefore, the lower the engine coolant temperature, the higher the signal
voltage output of the ECT sensor.
An ECT sensor DTC sets if the ECM detects the engine coolant temperature is outside the predetermined range.
Conditions for Running the DTC
DTC P0116
Runs continuously when the engine is running.
DTC P0117, P0118 and P1258
Runs continuously when the ignition is switched on.
DTC P00128
Runs once after the following conditions are met:
• DTCs P0112, P0113, P0117, P0118, P0480, and P0481 are not set.
• The engine is running.
Conditions for Setting the DTC
DTC P0116
The ECM detects the engine coolant temperature sensor value is 10°C less than the minimum calculated engine
temperature.
DTC P0117
The ECM detects the engine coolant temperature is greater than 140°C for longer than 3 seconds.
DTC P0118
The ECM detects the engine coolant temperature is less than -39°C for longer than 3 seconds.
DTC P0128
The ECM determines the calculated engine temperature by measuring the amount of airflow into the engine. This DTC
sets if the ECM detects the actual ECT sensor is not within 10ºC of the calculated engine temperature for approximately
2 – 5 minutes.
DTC P1258
The ECM detects the engine coolant temperature is greater than 131°C for longer than 2 seconds.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–105
Page 6C4-2–105
Conditions for Clearing the DTC
The ECT sensor DTCs are Type B DTCs. Refer to 1.5 Diagnostic Trouble Codes for action taken when a Type B DTC
sets and conditions for clearing Type B DTC.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the ECT sensor
operation.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• DTCs P0116, P0117, P0118 and P0128 diagnostic table is developed with the assumption the engine cooling
system is functioning correctly. Therefore, rectify any engine cooling system fault conditions before proceeding with
this diagnostic table.
• Test the ECT sensor using the ECT Temperature vs. Resistance in Section 6C4-3 Engine Management – GEN IV
V8 – Service Operations. If the engine has sat overnight, the ECT sensor should display within 3°C of the IAT
sensor values. When the engine is first started, the ECT should rise steadily to about 90°C then stabilise when
thermostat opens.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• To assist diagnosis, refer to 2 Wiring Diagrams and Connector Charts for the system wiring diagram and connector
charts.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
2 A fault condition in the engine cooling system may trigger these DTCs.
7 The ECT sensor low reference circuit is shared with other components. DTC P0118 may set if the shared low
reference circuit is shorted to voltage. Test the low reference circuit of all components that share this circuit to find
the source of the fault condition.
DTC P0116, P0117, P0118, P0128 and P1258 Diagnostic Table
Step Action Value(s) Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 Test the engine cooling system for correct operation.
Refer to 6B4 Engine Cooling – GEN IV V8.
Was any fault found and rectified? Go to Step 10 Go to Step 3
3 1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for
running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P0116, P0117, P0118, P0128 or P1258 fail
this ignition cycle? Go to Step 4
Refer to Additional
Information in this
Section
4 1 Switch off the ignition.
2 Disconnect the ECT sensor wiring connector.
3 Switch on the ignition with the engine not running.
4 Using a digital multimeter, measure the voltage
between the ECT sensor signal circuit and the ECM
housing.
Does the multimeter display between - ? 4.8 – 5.2 V Go to Step 5 Go to Step 6
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–106
Page 6C4-2–106
Step Action Value(s) Yes No
5 1 Switch off the ignition.
2 Remove ECM Fuse 29 from the engine
compartment fuse and relay panel assembly.
3 Using a digital multimeter, measure the resistance
between the ECT sensor low reference circuit and
the ECM housing.
NOTE
Install the ECM Fuse 29 to the engine
compartment fuse and relay panel assembly
after completing this test.
Does the multimeter display less than - 5 Ω? Go to Step 8 Go to Step 7
6 Test the IAT sensor signal circuit for a high resistance,
open circuit, short to ground or short to voltage fault
condition. Refer to 12P Wiring Diagrams for information
on electrical fault diagnosis.
Was any fault found and rectified? Go to Step 10 Go to Step 9
7 Test the ECT sensor low reference circuit for a high
resistance, open circuit, short to ground or short to
voltage fault condition. Refer to 12P Wiring Diagrams for
information on electrical fault diagnosis.
NOTE
The ECT sensor shares the low reference
circuit with other sensors. A fault condition in
the low reference circuit may trigger DT Cs on
sensors that share this circuit. Refer to 6.1
DTC List in Ascending Order to aid diagnosis.
Was any fault found and rectified? Go to Step 10 Go to Step 9
8 Replace the ECT sensor. Refer to 6C4-3 Engine
Management – GEN IV V8 – Service Operations.
Was the repair completed? Go to Step 10 —
9 Replace the ECM. Refer to 6C4-3 Engine Management –
GEN IV V8 – Service Operations.
Was the repair completed? Go to Step 10 —
10 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC.
Does any of the ECT sensor DTCs fail this ignition cycle? Go to Step 2 Go to Step 11
11 Using Tech 2, select the DTC display function.
Are there any DTCs displayed?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–107
Page 6C4-2–107
6.9 DTC P0120, P0121, P0122, P0123, P0220,
P0222, P0223, P1516, P2101, P2135.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0120 – Throttle Position Sensor 1 Circuit Range / Performance (Intermittent Short or Open Circuit)
• DTC P0121 – Throttle Position Sensor 1 Circuit Range / Performance (TP1 sticking)
• DTC P0122 – Throttle Position Sensor 1 Circuit Low Voltage
• DTC P0123 – Throttle Position Sensor 1 Circuit High Voltage
• DTC P0220 – Throttle Position Sensor 2 Circuit Range / Performance (Intermittent Short or Open Circuit)
• DTC P0222 – Throttle Position Sensor 2 Circuit Low Voltage
• DTC P0223 – Throttle Position Sensor 2 Circuit High Voltage
• DTC P1516 – Throttle Position Error (Excessive Electrical load)
• DTC P2101 – Throttle Position Error (T hrottle Plate Incorrect position)
• DTC P2135 – Throttle Position Error (Correlation between TP1 and TP2)
Circuit Description
The ECM applies 5 V to the throttle position (TP) sensor 1 through the 5 V reference circuit and the ground through the
low reference circuit. TP sensor 1 and TP sensor 2 share common 5 V reference circuit and low reference circuit.
The TP sensor 1 and TP sensor 2 have individual signal circuits with opposite functionality. These signal circuits provide
the ECM with a signal voltage that is proportional to the throttle plate movement.
• The TP sensor 1 signal voltage is less than 1 V when the throttle plate is in closed position, which increases to
greater than 4 V when the throttle plate is moved to wide-open throttle.
• The TP sensor 2 signal voltage is greater than 4 V when the throttle plate is in closed position, which decreases to
less than 1 V when the throttle plate is moved to wide-open throttle.
The ECM monitors and compares the TP sensor 1 signal voltage to the TP sensor signal voltage 2. In addition, the ECM
compares the TP sensor signal to the MAF sensor signal to determine a calculated TP sensor signal.
A TP sensor DTC sets if the ECM detects a fault condition in the TP sensor signal output.
Conditions for Running the DTC
The DTCs run continuously once the following conditions are met:
DTC P0120, P0121 or P0220
• The ignition voltage is greater than 7 V.
• The TP sensor 1 signal voltage is 0.17 – 4.6 V.
DTC P0122, P0123, P0222 and P0223
• The ignition voltage is greater than 7 V.
• The ignition is switched on.
Conditions for Setting the DTC
DTC P0120
The following conditions exist:
• The TP sensor 1 signal voltage and the TP sensor 2 signal voltage have a difference of greater than 9 percent.
• The TP sensor signal voltage has a difference of greater than 9 percent from the calculated TP sensor signal
voltage.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–108
Page 6C4-2–108
DTC P0121
The following conditions exist:
• The TP sensor 1 signal voltage and the TP sensor 2 signal voltage have a difference of greater than 9 percent.
• The TP sensor signal voltage has a difference of greater than 9 percent from the calculated TP sensor signal
voltage.
DTC P0122
The ECM detects the TP sensor 1 signal voltage is less than 0.18 volt.
DTC P0123
The ECM detects the TP sensor 1 signal voltage is greater than 4.6 V.
DTC P0222
The ECM detects the TP sensor 2 signal voltage is less than 0.16 volt.
DTC P0223
The ECM detects the TP sensor 2 signal voltage is greater than 4.8 V.
DTC P1516
• The ECM detects a higher than expected current draw on the throttle actuator
• The ECM detects a throttle positioning error
DTC P2101
The ECM detects a throttle positioning error.
DTC P2138
The ECM detects a continuous or intermittent correlation fault between TP1 and TP2.
Conditions for Clearing the DTC
DTCs P0210 P0121, P0122, P0123, P0220, P0222, P0223 and P2172 are Type B DTCs. Refer to 1.5 Diagnostic
Trouble Codes for action taken when a Type B DTC sets and conditions for clearing Type B DTCs.
DTCs P1516, P02101 and P2135 are Type A DTCs. Refer to 1.5 Diagnostic Trouble Codes for action taken when a
Type A DTC sets and conditions for clearing Type A DTCs.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the TP sensor
operation.
• The ECM defaults to a reduced power mode if there is a fault condition in the TP sensor circuits for the entire
ignition cycle, even if the fault condition is corrected.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• The TP sensors share a common 5 V reference circuit, test for a fault condition in the 5 V reference circuit if DTC
P0222 is set.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• To assist diagnosis, refer to 2 Wiring Diagrams and Connector Charts for the system wiring diagram and connector
charts.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–109
Page 6C4-2–109
Test Description
The following numbers refer to the step numbers in the diagnostic chart:
2 This Step verifies that a fault condition exists. Tech 2 will display Disagree if there is a fault condition in the TP
sensor circuit.
8 This Step tests for high resistance in the TP sensor low reference circuit. The ECM must be completely powered
down to obtain an accurate resistance reading. It may take up to 30 minutes for the ECM to power down after the
ignition key is removed. Removal of the ECM/TCM fuse allows the ECM to power down completely.
Diagnostic Table for the TP Sensor Circuit DTCs
Step Action Value(s) Yes No
1 Was the Diagnostic System Check performed?
– Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Start the engine.
2 On Tech 2 select:
Engine / Data Display
Does Tech 2 display Okay? – Go to Step 3
Refer to Additional
Information in this
section
3 1 Switch off the ignition for 30 seconds.
2 Switch on the ignition.
3 Perform the following tests several times:
• Quickly depress the accelerator pedal to
wide-open throttle then release pedal.
• Slowly depress the accelerator pedal to
wide-open throttle then slowly return the
pedal to the closed throttle position.
3 Using Tech 2 select:
Engine / Diagnostic Trouble Codes / Read DTC
Information.
Does DTC P0120, P0121, P0122, P0123, P0220,
P0222, P0223, P1516, P2101, P2135 or P2176 fail this
ignition cycle? – Go to Step 4
Refer to 4.2
Intermittent Fault
Conditions
4 1 Disconnect the throttle actuator wiring connector.
2 Switch on the ignition with the engine not running.
3 Using a digital multimeter, measure the voltage
between each of the TP sensor 5 volts reference
circuits and the TACM housing.
Is the voltage within the specified range? 4.8 – 5.2 V Go to Step 5 Go to Step 8
5 1 Connect a 3 amp fused jumper wire between the
TP sensor 1 5 volts reference circuit 1 and the TP
sensor 1 signal circuit.
2 Switch on the ignition with the engine not running.
3 Using Tech 2, observe the TP sensor 1 voltage
parameter.
Is the voltage within the specified value? 4.8 – 5.2 V Go to Step 6 Go to Step 9
6 1 Connect a 3 amp fused jumper wire between the
TP sensor 2 5 volts reference circuit 2 and the TP
sensor 2 signal circuit.
2 Using Tech 2, observe the TP sensor 2 voltage
parameter.
Is the voltage within the specified value? 4.8 – 5.2 V Go to Step 7 Go to Step 10
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–110
Page 6C4-2–110
Step Action Value(s) Yes No
7 1 Switch off the ignition.
2 Remove ECM Fuse 29 from the engine
compartment fuse and relay panel assembly.
3 Using a digital multimeter, measure the resistance
between the TP sensor low reference circuit and
the ECM housing.
NOTE
Install the ECM Fuse 29 to the engine
compartment fuse and relay panel assembly
after completing the test.
Is the resistance less than the specified value? 5 Ω Go to Step 12 Go to Step 11
8 Test the appropriate TP sensor 5 volts reference circuit
for a high resistance, open circuit, short to ground or
short to voltage fault condition. Refer to 12P Wiring
Diagrams for information on electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 14 Go to Step 13
9 Test the TP sensor 1 signal circuit for a high resistance,
open circuit, short to ground or short to voltage fault
condition. Refer to 12P Wiring Diagrams for information
on electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 14 Go to Step 13
10 Test the TP sensor 2 signal circuit for a high resistance,
open circuit, short to ground or short to voltage fault
condition. Refer to 12P Wiring Diagrams for information
on electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 14 Go to Step 13
11 Test the appropriate TP sensor low reference circuit for
a high resistance or an open circuit fault condition.
Refer to 12P Wiring Diagrams for information on
electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 14 Go to Step 13
12 Replace the throttle body assembly. Refer to 6C4-3
Engine Management – GEN IV V8 – Service
Operations.
Was the repair completed? – Go to Step 14 –
13 Replace the ECM. Refer to 6C4-3 Engine
Management – GEN IV V8 – Service Operations.
Was the repair completed? – Go to Step 14 –
14 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
Do any of the TP Sensor Circuit DTCs fail this ignition
cycle? – Go to Step 2 Go to Step 15
15 Using Tech 2, select the DTC display function.
Are there any DTCs displayed? –
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–111
Page 6C4-2–111
6.10 DTC P0131, P0132, P0133, P0134, P0137,
P0138, P0140, P0151, P0152, P0153,
P0154, P0157, P0158, P0160, P1133,
P1153, P2A01, P2A04
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0131 – Heated O2 Sensor Circuit Low Voltage Bank 1 Sensor 1
• DTC P0132 – Heated O2 Sensor Circuit High Voltage Bank 1 Sensor 1
• DTC P0133 – Heated O2 Sensor Slow Response Bank 1 Sensor 1
• DTC P0134 – Heated O2 Sensor Circuit Insufficient Activity Bank 1 Sensor 1
• DTC P0136 – Heated O2 Sensor Circuit Range/Performance Bank 1 Sensor 2
• DTC P0137 – Heated O2 Sensor Circuit Low Voltage Bank 1 Sensor 2
• DTC P0138 – Heated O2 Sensor Circuit High Voltage Bank 1 Sensor 2
• DTC P0140 – Heated O2 Sensor Circuit Insufficient Activity Bank 1 Sensor 2
• DTC P0151 – Heated O2 Sensor Circuit Low Voltage Bank 2 Sensor 1
• DTC P0152 – Heated O2 Sensor Circuit High Voltage Bank 2 Sensor 1
• DTC P0153 – Heated O2 Sensor Slow Response Bank 2 Sensor 1
• DTC P0154 – Heated O2 Sensor Circuit Insufficient Activity Bank 2 Sensor 1
• DTC P0156 – Heated O2 Sensor Circuit Range/Performance Bank 2 Sensor 2
• DTC P0157 – Heated O2 Sensor Circuit Low Voltage Bank 2 Sensor 2
• DTC P0158 – Heated O2 Sensor Circuit High Voltage Bank 2 Sensor 2
• DTC P0160 – Heated O2 Sensor Circuit Insufficient Activity Bank 2 Sensor 2
• DTC P1133 – Heated O2 Sensor Circuit Insufficient Switching Bank 1 Sensor 1
• DTC P1153 – Heated O2 Sensor Circuit Insufficient Switching Bank 2 Sensor 1
• DTC P2A01 – Heated O2 Sensor Circuit Range/Performance Bank 1 Sensor 2
• DTC P2A04 – Heated O2 Sensor Circuit Range/Performance Bank 2 Sensor 2
Circuit Description
The engine control relay applies positive voltage to the heater ignition voltage circuits of the Heated O2 Sensor. The
ECM applies a pulse width modulated (PWM) ground to the heater control circuit of the Heated O2 Sensor through a
device within the ECM called a driver, to control the Heated O2 Sensor rate of heating.
Heated O2 Sensor
The ECM applies a voltage of approximately 450 mV between the reference signal circuit and low reference circuit of the
Heated O2 Sensor while the sensor temperature is less than the operating range.
Once the Heated O2 Sensor reaches operating temperature, the sensor varies this reference signal voltage, which
constantly fluctuates between the high voltage output and the low voltage output.
• The low voltage output is 0 – 450 mV, which occurs if the air fuel mixture is lean.
• The high voltage output is 450 – 1,000 mV, which occurs if the air fuel mixture is rich.
The ECM monitors, stores and evaluates the Heated O2 Sensor voltage fluctuation information to determine the level of
oxygen concentration in the exhaust.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–112
Page 6C4-2–112
Conditions for Running the DTC
The DTCs run continuously once the following conditions are met:
DTC P0131, P0137, P0151 or P0157
• Closed loop control
• TPS between 3 – 70%
• Greater than 10% fuel
• System voltage between 10 volts and 18 volts
DTC P0132, P0138, P0152 or P0158
• Closed loop control
• TPS between 3 – 70%
• Greater than 10% fuel
• System voltage between 10 volts and 18 volts
DTC P0133 or P0153
• Closed loop control
• Engine running for longer than 160 seconds
• Engine speed between 1000 and 3000 RPM
• Airflow between 18 and 55g/s
• System voltage between 10 and 18 volts
• TPS greater than 5%
• Fuel greater than 10%
• ECT higher 60°C
DTC P0134, P0140, P0154 or P0160
• Engine running for longer than 300 seconds
• System voltage between 10 and 18 volts
DTC P1133 or P1153
• Closed loop control
• Engine running for longer than 160 seconds
• Engine speed between 1000 and 3000 RPM
• Airflow between 18 and 55g/s
• System voltage between 10 and 18 volts
• TPS greater than 5%
• Fuel greater than 10%
• ECT higher 60°C
DTC P2A01 or P2A04
• Engine running
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–113
Page 6C4-2–113
Conditions for Setting the DTC
DTC P0131, P0137, P0151 or P0157
The following conditions exist:
The ECM internal Heated O2 Sensor voltage is less than the specified threshold.
DTC P0132, P0138, P0152 or P0158
The following conditions exist:
The ECM internal Heated O2 Sensor voltage is greater than the specified threshold
DTC P0133 or P0153
The following conditions exist:
The voltage variation switching signal from the upstream Heated O2 Sensor sensors is slower than predicted
DTC P0134, P0140, P0154 or P0160
The following conditions exist
• There is no switching signal detected by the ECM
• The switching signal fails to reach the thresholds determined by the ECM
DTC P1133 or P1153
The following conditions exist:
• The switching signal voltage reaches the predetermined thresholds
• The time between the switching signals exceed the predicted thresholds
DTC P2A01 or P2A04
The following conditions exist:
The switching ratio between the upstream Heated O2 Sensors and the downstream Heated O2 Sensors fails to reach the
predicted thresholds.
Conditions for Clearing the DTC
The Heated O2 Sensor reference circuit DTCs are Type B DTCs. Refer to 1.5 Diagnostic Trouble Codes for action taken
when Type B DTC sets and conditions for clearing Type B DTCs.
Additional Information
• Refer to Section 6C4-1 Engine Management GEN IV V8 – General Information for details of the Heated O2 Sensor
system operation.
• For an intermittent fault condition, Refer to 4.2 Intermittent Fault Conditions.
• The Heated O2 Sensor must be correctly fitted and tightened to the specified torque value. A loose Heated O2
Sensor can trigger these DTCs.
• A fault condition in the fuel delivery system, air intake system, exhaust system or mechanical system may trigger
these DTCs.
• Inspect the Heated O2 Sensor wiring harness for contact with the exhaust system.
• An oxygen supply inside the Heated O2 Sensor is necessary for correct function and operation. The Heated O2
Sensor wires allow the supply of oxygen through to the sensing element. Inspect the Heated O2 Sensor wires and
connections for breaks or contamination.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• DTCs P0131, P0132, P0137, P0138, P0151, P0152, P0157 or P0158 are more commonly associated with wiring
concerns. If a heater DTC is also recorded, refer to 6.3 DTC P0030, P0036, P0050 P0053, P0054, P0056, P0059,
P0060, P0135, P0141, P0155, P0161, investigate and rectify these as the primary cause of the concern.
• The remaining DTCs indicate the possibility of a mechanical concern or sensor contamination. Ensure the fuel,
ignition and engine mechanical systems are operating within the correct specifications.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–114
Page 6C4-2–114
Diagnostic Table for the Heated Oxygen Sensor Reference Circuit DTCs
Step Action Value(s) Yes No
1 Has the Diagnostic System Check been performed?
– Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch off the ignition for 30 seconds.
2 Start the engine.
3 Allow the engine to reach the normal operating
temperature.
4 Increase the engine speed to 2,000 RPM for 10
seconds or operate the vehicle within the
conditions for setting the DTC.
5 Using Tech 2 select:
Engine / Diagnostic Trouble Codes / Read DTC
Information.
Does DTC P0131, P0132, P0133, P0134, P0136,
P0137, P0138, P0140, P0151, P0152, P0153, P0154,
P0156, P0157, P0158, P0160, P1133, P1134, P1153,
P1154, P2A01 or P2A04 fail this ignition cycle? – Go to Step 3
Refer to Additional
information in this
section
3 Are any DTCs relating to the heater circuit of the
Heated O2 Sensor also set?
–
Refer to 6.3 DTC
P0030, P0036,
P0050 P0053,
P0054, P0056,
P0059, P0060,
P0135, P0141,
P0155, P0161 Go to Step 4
4 1 Switch off the ignition.
2 Disconnect the appropriate Heated O2 Sensor
wiring connector.
3 Switch on the ignition with the engine not running.
4 Using a digital multimeter, measure the voltage
between the Heated O2 Sensor reference signal
circuit and low reference circuit.
Is the HO2S voltage within the specified range? 350 – 550
mV Go to Step 7 Go to Step 5
5 Test the reference signal circuit of the Heated O2
Sensor for a high resistance, open circuit, short to
ground or short to voltage fault condition. Refer to 12P
Wiring Diagrams for information on electrical fault
diagnosis.
Was any fault found and rectified? – Go to Step 10 Go to Step 6
6 Test the low reference circuit of the Heated O2 Sensor
for a high resistance, open circuit, short to ground or
short to voltage fault condition. Refer to 12P Wiring
Diagrams for information on electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 10 Go to Step 9
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–115
Page 6C4-2–115
Step Action Value(s) Yes No
7 Test or inspect for the following conditions that may
cause the Heated O2 Sensor to detect an incorrect
air/fuel mixture:
• lean or rich fuel injector fuel delivery,
• restricted air intake system,
• contaminated fuel,
• low fuel line pressure,
• exhaust leak near the Heated O2 Sensor, and
• leak in the crankcase or vacuum line.
IMPORTANT
The engine must be in correct mechanical
order as items such as incorrect valve
timing, clearances or excessive piston wear
can induce these DTCs
Was any fault found and rectified? – Go to Step 10 Go to Step 8
8 Replace the appropriate Heated O2 Sensor. Refer to
6C4-3 Engine Management GEN IV V8 – Service
Operations.
Was the repair completed? – Go to Step 10 –
9 Replace the ECM. Refer to 6C4-3 Engine Management
GEN IV V8 – Service Operations.
Was the repair completed? – Go to Step 10 –
10 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
Do any Heated O2 Sensor reference circuit DTCs fail
this ignition cycle? – Go to Step 2 Go to Step 11
11 Using Tech 2, select the DTC display function.
Are there any DTCs displayed? –
Go to the
appropriate
DTC Table System OK
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–116
Page 6C4-2–116
6.11 DTC P0171, P0172, P0174, P0175
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0171 – Fuel System Lean Bank 1
• DTC P0172 – Fuel System Rich Bank 1
• DTC P0174 – Fuel System Lean Bank 2
• DTC P0175 – Fuel System Rich Bank 2
Circuit Description
The ECM applies a voltage of approximately 450 mV between the Heated Oxygen Sensor (Heated O2 Sensor) signal
circuit and Heated O2 Sensor low reference circuit. The Heated O2 Sensor varies the signal voltage, which constantly
fluctuates between the high voltage output and the low voltage output.
• The low voltage output is between 0 – 450 mV, which occurs if the air fuel mixture is lean.
• The high voltage output is between 450 – 1,000 mV, which occurs if the air fuel mixture is rich.
The ECM monitors and evaluates the Heated O2 Sensor voltage fluctuation information in order to determine the level of
oxygen concentration in the exhaust. A Heated O2 Sensor reference circuit DTC sets if the ECM detects that the Heated
O2 Sensor signal voltage is outside a predetermined range for a specified time.
Conditions for Running the DTC
The DTCs run continuously once the following conditions are met:
DTCs P0171, P0172, P0174, and P0175
• No Throttle, Fuel Injector, Air Flow, Purge Control, MAP, or other Heated O2 Sensor faults active.
• The engine coolant temperature is -40 - 139°C.
• The MAF signal is between 1 - 250 g/s.
• The MAP signal is between 15 - 105 kPa.
• The IAT signal is between 0 - 152°C.
• The engine speed is between 400 - 6500 RPM.
• The vehicle speed is less than 130 km/h.
• The fuel tank level is more than 10%.
Conditions for Setting the DTC
DTCs P0171 and P0174
The following conditions exist:
The average Long Term fuel trim value is greater than +24%.
DTCs P0172 and P0175
The following conditions exist:
The average Long Term fuel trim value is below -17%, with no excessive canister purge vapours present.
Conditions for Clearing the DTC
DTCs, P0171, P0172, P0174, and P0175 are Type B DTCs. Refer to 1.5 Diagnostic Trouble Codes for action taken
when Type B DTCs set and conditions for clearing Type B DTCs.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–117
Page 6C4-2–117
Additional Information
• Refer to Section 6C4-1 Engine Management GEN IV V8 – General Information for details of the Heated O2 Sensor
system operation.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• The Heated O2 Sensor must be torqued correctly. A loose Heated O2 Sensor will trigger these DTCs.
• A fault condition in the fuel delivery system, air intake system or exhaust system may trigger these DTCs.
• Inspect the Heated O2 Sensor wiring harness for contact with the exhaust system.
• An oxygen supply inside the Heated O2 Sensor is necessary for proper operation. The Heated O2 Sensor wires
provide the supply of oxygen. Inspect the Heated O2 Sensor wires and connections for breaks or contamination.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• Refer to 2 Wiring Diagrams and Connector Charts to aid in the diagnosis procedures.
Diagnostic Table for the Fuel Trim Reference Circuit DTCs
Step Action Value(s) Yes No
1 Has the Diagnostic System Check been performed?
– Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch off the ignition for 30 seconds.
2 Start the engine.
3 Allow the engine to reach the normal operating
temperature.
4 Increase the engine speed to 2,000 RPM for 10
seconds or operate the vehicle within the
conditions for setting the DTC.
5 Using Tech 2 select:
Engine / Diagnostic Trouble Codes / Read DTC
Information.
Does DTC P0171, P0172, P0174, or P0175 fail this
ignition cycle? – Go to Step 3
Refer to Additional
Information in this
section
3 Are any DTCs relating to the heater circuit of the
Heated O2 Sensor also set? – Refer to appropriate
DTC table Go to Step 4
4 1 Switch off the ignition.
2 Disconnect the appropriate Heated O2 Sensor
wiring connector.
3 Switch on the ignition with the engine not running.
4 Using a digital multimeter, measure the voltage
between the Heated O2 Sensor reference signal
circuit and low reference circuit.
Is the HO2S voltage within the specified range? 350 – 550
mV Go to Step 7 Go to Step 5
5 Test the reference signal circuit of the Heated O2
Sensor for a high resistance, open circuit, short to
ground or short to voltage fault condition. Refer to 12P
Wiring Diagrams for information on electrical fault
diagnosis.
Was any fault found and rectified? – Go to Step 10 Go to Step 6
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–118
Page 6C4-2–118
Step Action Value(s) Yes No
6 Test the low reference circuit of the Heated O2 Sensor
for a high resistance, open circuit, short to ground or
short to voltage fault condition. Refer to 12P Wiring
Diagrams for information on electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 10 Go to Step 9
7 Test or inspect for the following conditions that may
cause the Heated O2 Sensor to detect an incorrect
air/fuel mixture:
• lean or rich fuel injector fuel delivery,
• restricted air intake system,
• contaminated fuel,
• low fuel line pressure,
• exhaust leak near the Heated O2 Sensor, and
• leak in the crankcase or vacuum line.
Was any fault found and rectified? – Go to Step 10 Go to Step 8
8 Replace the appropriate Heated O2 Sensor. Refer to
6C4-3 Engine Management – GEN IV V8 – Service
Operations.
Was the repair completed? – Go to Step 10 –
9 Replace the ECM. Refer to 6C4-3 Engine
Management – GEN IV V8 – Service Operations.
Was the repair completed? – Go to Step 10 –
10 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
Do any Heated O2 Sensor reference circuit DTCs fail
this ignition cycle? – Go to Step 2 Go to Step 11
11 Using Tech 2, select the DTC display function.
Are there any DTCs displayed? –
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–119
Page 6C4-2–119
6.12 DTC P0201, P0202, P0203, P0204, P0205,
P0206, P0207, P0208
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0201 – Injector 1 Control Circuit Malfunction
• DTC P0202 – Injector 2 Control Circuit Malfunction
• DTC P0203 – Injector 3 Control Circuit Malfunction
• DTC P0204 – Injector 4 Control Circuit Malfunction
• DTC P0205 – Injector 5 Control Circuit Malfunction
• DTC P0206 – Injector 6 Control Circuit Malfunction
• DTC P0207 – Injector 7 Control Circuit Malfunction
• DTC P0208 – Injector 8 Control Circuit Malfunction
Circuit Description
The engine control relay applies ignition positive voltage to the fuel injector ignition circuit. The ECM applies a pulse width
modulated (PWM) ground to the injector control circuit through a device within the ECM called a driver to control each
fuel injector on time.
The driver has a feedback circuit that is pulled-up when the voltage is approximately 3.3 V. The ECM monitors the Driver
feedback circuit to determine if the control circuit is open, shorted to ground or shorted to a positive voltage.
A fuel injector control circuit DTC sets if the ECM detects a fault condition in a fuel injector control circuit.
Conditions for Running the DTC
Run continuously once the following conditions are met:
• the battery voltage is 10.0 – 16.0 V, and
• engine speed is greater than 80 rpm.
Conditions for Setting the DTC
DTC P0201, P0202, P0203, P0204, P0205, P0206, P0207 or P0208
The ECM detects an open circuit fault condition in a fuel injector circuit.
Conditions for Clearing the DTC
The fuel injector control circuit DTCs are Type B DTCs. Refer to 1.5 Diagnostic Trouble Codes for action taken when
Type B DTC sets and conditions for clearing Type B DTCs.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the fuel injector
operation.
• Using Tech 2, observe the appropriate fuel injector status parameter while wriggle testing related harness and
connectors. Tech 2 reading will change from Ok to Fault if there is an intermittent fault condition in the harness or
connector being tested.
• Perform the fuel injector coil test to help isolate an intermittent condition. Refer to Section 6C4-3 Engine Management
–GEN IV V8 – Service Operations.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–120
Page 6C4-2–120
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• To assist diagnosis, refer to 2 Wiring Diagrams and Connector Charts, for the system wiring diagram and
connector charts.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
3 Determines if there is a fault condition in the ignition voltage supply circuit. The fuel injectors for each bank of the
engine are fused separately. If all DTCs for a single bank are set, there may be a fault in one of the ignition supply
circuits.
5 Verifies the ECM is sending control voltage to the fuel injector.
6 Tests if the feed back voltage circuit within the ECM is providing the correct voltage.
DTC P0201 to P0208, Diagnostic Table
Step Action Values Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch off the ignition for 30 seconds.
2 Start the engine.
3 Using Tech 2, select the DTC display function.
Does DTC P0201, P0202, P0203, P0204, P0205, P0206,
P0207 or, P0208 set? Go to Step 3
Refer to Additional
Information in this
Section
3 1 Disconnect the fuel injector interconnect harness
connector. Refer to 6C4-3 Engine Management –
GEN IV V8 – Service Operations.
2 Switch on the ignition with the engine not running.
3 Connect a test lamp between the ignition voltage
circuit of the appropriate fuel injector, ECM side of
the interconnect connector, and the ECM housing.
Does the test lamp illuminate? Go to Step 4 Go to Step 5
4 1 Switch on the ignition with the engine not running.
2 Using a digital multimeter, measure the voltage
between the appropriate fuel injector control circuit,
ECM side of the interconnect connector, and the
ECM housing.
Does the multimeter display between the specified
values? 2.6-4.6 mV Go to Step 7 Go to Step 6
5 Repair the open circuit or short to ground fault condition
in the ignition voltage circuit of the appropriate fuel
injector. Refer to 12P Wiring Diagrams for information on
electrical wiring repair procedures.
Was the repair completed? Go to Step 10 —
6 Test the control circuit of the appropriate fuel injector,
between the interconnect connector and the ECM, for a
high resistance, open circuit, short to ground or short to
voltage fault condition. Refer to 12P Wiring Diagrams for
information on electrical fault diagnosis.
Was any fault found and rectified? Go to Step 10 Go to Step 9
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–121
Page 6C4-2–121
Step Action Values Yes No
7 1 Test the control circuit and the ignition voltage
circuit of the appropriate fuel injector, between the
interconnect connector and the appropriate fuel
injector connector, for a high resistance, open
circuit, short to ground or short to voltage fault
condition. Refer to 12P Wiring Diagrams for
information on electrical fault diagnosis.
Was any fault found and rectified? Go to Step 10 Go to Step 8
8 Replace the appropriate fuel injector. Refer to 6C4-3
Engine Management – GEN VI V8 – Service Operations.
Was the repair completed? Go to Step 10 —
9 Replace the ECM. Refer to 6C4-3 Engine Management –
GEN IV V8 – Service Operations.
Was the repair completed? Go to Step 10 —
10 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC.
Does any of the fuel injector control circuit DTCs fail this
ignition cycle? Go to Step 2 Go to Step 11
11 Using Tech 2, select the DTC display function.
Are there any DTCs displayed?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–122
Page 6C4-2–122
6.13 DTC P0230
DTC Description
This diagnostic procedure covers DTC P0230 – Fuel Pump Control Circuit.
Circuit Description
When the ignition switch is turned on, the ECM energises the fuel pump circuit and the fuel pump runs and builds up
pressure in the fuel system. If the ECM does not receive reference pulses from the crankshaft position sensor, the fuel
pump circuit will be de-energised after 2 seconds. When the ignition switch is moved to the ST ART position, the fuel
pump circuit will become energised by the ECM once reference pulses are received from the crankshaft position sensor.
The ECM controls the fuel pump relay by applying B+ to the control circuit via an internal switch called a driver. The
primary function of the driver is to supply a voltage to the fuel pump relay. The driver has a fault line which the ECM
monitors. When the ECM commands the fuel pump on, the voltage of the control circuit should be high (near battery
voltage). When the ECM commands the control circuit to the fuel pump off, the voltage potential of the circuit should be
low (near 0 volts). DTC P0230 will set when the ECM detects the fuel pump control circuit is shorted to ground while the
engine is running. If the short occurs before the ignition is switched on, the DTC will not set and the fuel pump will not
operate.
Diagnostic Aids for the Fuel Pump Control Circuit DTCs
Conditions for Running the DTC
• The engine speed is greater than 0 RPM.
• The ignition voltage is between 10.0 and 18.0 V.
Conditions for Setting the DTC
The ECM detects that the commanded state of the circuit and the actual state of the circuit do not match.
Conditions for Clearing the DTC
DTC P0230 – Fuel Pump Control Circuit is a Type B DTC. Refer to 1.5 Diagnostic Trouble Codes for action taken when
a Type B DTC sets and conditions for clearing Type B DTC.
Additional Information
• Refer to Section 6C4-1 Engine Management GEN IV V8 – General Information for details of the fuel pump
operation.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• Refer to 2 Wiring Diagrams and Connector Charts to aid in the diagnosis procedures.
Test Descriptions
The following numbers refer to the step numbers in the diagnostic chart:
5 The telematics system, where fitted, has the ability to isolate the fuel pump relay control circuit.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–123
Page 6C4-2–123
Diagnostic Table for the Fuel Pump Control Circuit DTCs
Step Action Yes No
1 Was the Main Diagnostic System performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Observe the Freeze Frame / Failure Record for this DTC.
2 Switch off the ignition for 30 seconds.
3 Operate the vehicle within the conditions for running the DTC or
within the conditions in the Freeze Frame / Failure Records.
4 Using Tech 2 select:
Engine / Diagnostic Trouble Codes / Read DTC Information.
Does DTC P0230 fail this ignition cycle? Go to Step 3
Refer to
Diagnostic Aids for
the Fuel Pump
Control Circuit
DTCs
3 1 Switch off the ignition.
2 Remove the fuel pump relay (R16) from the engine compartment
fuse & relay panel.
3 Connect a test lamp between the fuel pump relay control circuit
and the fuel pump relay ground circuit.
4 Switch on the ignition with the engine not running.
5 Using Tech 2, command the fuel pump relay On and Off.
Does the test lamp turn on and off when commanded? Go to Step 10 Go to Step 4
4 1 Connect a test lamp between the fuel pump relay control circuit
and a known ground.
2 Switch on the ignition with the engine not running.
3 Using Tech 2, command the fuel pump relay On and Off.
Does the test lamp turn on and off when commanded? Go to Step 9 Go to Step 5
5 Is the vehicle fitted with telematics? Go to Step 6 Go to Step 8
6 1 Disconnect connector from the telematics transceiver module.
2 Connect a test lamp between the fuel pump relay control circuit
(ECM side) and a known ground.
3 Switch on the ignition with the engine not running.
4 Using Tech 2, command the fuel pump relay On and Off.
Does the test lamp turn on and off when commanded? Go to Step 7 Go to Step 8
7 1 Connect a test lamp between the fuel pump relay control circuit
(relay side) and a known ground.
3 Switch on the ignition with the engine not running.
4 Using Tech 2, command the fuel pump relay On and Off.
Does the test lamp turn on and off when commanded? Go to Step 8 Refer to 12K
Telematics
8 Test the fuel pump relay control circuit for a high resistance, open
circuit, short to voltage, or short to ground fault condition. Refer to 12P
Wiring Diagrams for information on electrical wiring repair procedures.
Was any fault found and rectified? Go to Step 12 Go to Step 11
9 Repair the high resistance or open circuit fault condition in the fuel
pump relay ground circuit. Refer to 12P Wiring Diagrams for
information on electrical wiring repair procedures.
Was the repair completed? Go to Step 12 –
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–124
Page 6C4-2–124
Step Action Yes No
10 Replace the Fuel Pump Relay R16.
Was the repair completed? Go to Step 12 –
11 Replace the ECM. Refer to 6C4-3 Engine Management GEN IV V8 –
Service Operations.
Was the repair completed? Go to Step 12 –
12 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC or
within the conditions in the Freeze Frame / Failure Records.
Does DTC P0230 fail this ignition cycle? Go to Step 2 Go to Step 13
13 Using Tech 2, select the DTC display function.
Are there any DTCs displayed?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–125
Page 6C4-2–125
6.14 DTC P0300, P1380, P1381
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC.P0300 Engine Misfire Detected.
DTC.P1380 Engine Misfire Detected – Rough Road
DTC.P1381 Engine Misfire Detected – No Communication with Brake Control Module
Circuit Description
The engine control module (ECM) uses information from the crankshaft position (CKP) sensor and the camshaft position
(CMP) sensors to determine when an engine misfire is occurring. By monitoring variations in the crankshaft rotation
speed for each cylinder, the ECM is able to detect individual misfire events. A misfire rate that is high enough can cause
3-way catalytic converter damage. The malfunction indicator lamp (MIL) will flash ON and OFF when the conditions for
catalytic converter damage are present. If the misfire rate is sufficient to cause emission levels to exceed a
predetermined value, this DTC sets.
Conditions for Running the DTCs
• DTCs P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0335, or P0336 are not set.
• The engine speed is between 400 – 7,000 rpm and steady.
• The delivered torque signal is more than 10 percent at idle.
• The delivered torque signal is between 9 – 30 percent with the transmission in drive.
• The intake air temperature (IAT) is more than –30° C.
• The fuel level is more than 12 percent.
• The torque management is not active.
• The antilock brake system/traction control system (ABS/TCS) is not active.
• The fuel cut-off is not active, including the traction control, the deceleration, the high vehicle speed, and the high
engine speed.
• DTC P0300 runs continuously when the above conditions exist for at least 1,000 engine revolutions.
Conditions for Setting the DTC
• The ECM detects a crankshaft rotation speed variation indicating a misfire rate sufficient to cause emissions levels
to exceed mandated standards.
• The condition above exists for more than 4 seconds.
Action Taken When the DTC Sets
• The control module activates the MIL on the second ignition cycle that the diagnostic runs and fails.
• The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic
fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the
second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The
control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the MIL/DTC
• The ECM turns OFF the malfunction indicator lamp (MIL) after 4 consecutive ignition cycles that the diagnostic runs
and does not fail.
• A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
• A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission
related diagnostic.
• Use Tech 2 to clear the MIL and the DTC.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–126
Page 6C4-2–126
Additional Information
DTCs P0300 and P1380
• A misfire DTC could be caused by an excessive vibration from sources other than the engine. Inspect for the
following possible sources:
A tyre or wheel that is out of round or out of balance
Variable thickness brake rotors
An unbalanced drive shaft
Certain rough road conditions
A damaged accessory drive component or belt
Enthusiastic driving
• For an intermittent condition, refer to 4.2 Intermittent Fault Conditions
DTC P1381
This indicates a communications failure with the ABS module. Check and ensure there is no “U” code DTCs recorded.
Refer to Section 6E4 Powertrain Interface Module – GEN IV V8.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
2 This step determines if there is a current condition.
4 If the Misfire Current Counters are incrementing, but the engine is NOT misfiring, this indicates a mechanical
condition. For example, an accessory drive belt could cause this condition.
DTC P0300, P1380 and P1381 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been completed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2
IMPORTANT
The engine may only misfire when the engine is under a
load. An engine load may be necessary to verify the
condition.
1 Start the engine.
2 Use Tech 2 to monitor the Misfire Current Cyl 1 – 8 parameters.
Are any of the Misfire Current Counters incrementing? Go to Step 4. Go to Step 3
3
1 Clear the DTC.
1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P0300 fail this ignition cycle? Go to Step 4
Refer to Additional
Information in this
section
4 Is the engine misfiring? Go to Step 5
Refer to
4.1 Symptom
Diagnosis Table
5 1 Observe the DTC information using Tech 2.
Is DTC P0201-P0208, P0335, P0336, P0351 or P0358, also set?
Go to the
appropriate
DTC Table Go to Step 6
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–127
Page 6C4-2–127
Step Action Yes No
6
Is there an engine mechanical noise?
Go to Symptoms in
6A4 Engine
Mechanical –
GEN IV V8 Go to Step 7
7 Is there more than one cylinder specific misfire DTC set? Go to Step 8 Go to Step 9
8 Are there any heated oxygen sensor (Heated O2 Sensor) DTCs set?
Go to the
appropriate
DTC Table Go to Step 9
9
1 Inspect or test for the following conditions:
• Inspect the vacuum hoses for splits, kinks, and proper
connections.
• Inspect the throttle body and the intake manifold for
vacuum leaks.
• Inspect the crankcase ventilation valve and/or system for
any vacuum leaks.
• Test for the correct fuel pressure. Refer to 8A1 Fuel
System.
• Inspect the fuel system for any restrictions, leaks or fuel
contamination. Refer to 8A1 Fuel System.
• Inspect for fouled or damaged spark plugs. Determine
what caused the spark plugs to foul. Refer to 6C4-3 Engine
Management – Service Operations.
• Inspect the exhaust system for restrictions. Refer to
8B Exhaust System.
• Inspect the engine control grounds for being clean, tight,
and in the correct location.
2 Repair as required.
Did you find and correct the condition? Go to Step 10
Go to Symptoms in
6A4 Engine
Mechanical –
GEN IV V8
10
1 Use Tech 2 to clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the Conditions for Running the DTC
Did the DTC fail this ignition? Go to Step 2 Go to Step 11
11 1 Using Tech 2, select the DTC display function.
Does Tech display any DTCs?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, clear all DTCs and verify correct operation
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–128
Page 6C4-2–128
6.15 DTC P0315, P0335, P0336 and P0654
DTC Description
This diagnostic procedure covers the following DTCs:
• DTC P0315 – Crankshaft position system variation not learned
• DTC P0335 – Crankshaft Position Sensor Circuit
• DTC P0336 – Crankshaft Position Sensor Circuit Performance
• DTC P0654 – Engine Speed Output Circuit
Circuit Description
DTC P0315 the crankshaft position (CKP) system variation learn feature is used to calculate reference period errors
caused by slight tolerance variations in the crankshaft and the CKP sensor. The calculated error allows the engine
control module (ECM) to accurately compensate for reference period variations. This enhances the ability of the ECM to
detect misfire events over a wide range of engine speed and load. The ECM stores the crankshaft position system
variations values after a learn procedure has been performed. If the CKP system variation values are not stored in the
ECM memory, DTC P0315 will set
The Crankshaft Position Sensor (CKP) is mounted in the right rear of the engine block behind the starter. The CKP
Sensor works in conjunction with a 24X reluctor wheel mounted on the rear of the crankshaft. The CKP Sensor has a B+
power supply, a ground, and a signal circuit.
As the crankshaft rotates, the reluctor wheel teeth interrupt a magnetic field produced by a magnet within the sensor.
Internal circuitry detects these fluctuations and enables the sensor to produce a signal which the ECM reads. T he ECM
uses this signal to accurately measure crankshaft velocity which is a variable used to detect engine speed for spark and
fuelling.
A CKP sensor DTC sets if the ECM detects a fault condition in the CKP sensor signal circuit.
Conditions for Running the DTCs
DTC P0315
• DTCs P0335, P0336 or P0341 are not set.
• DTC P0315 runs every 100 milliseconds.
DTC P0335
• No camshaft position sensor or airflow DTCs set.
• The MAF is greater than 3 g/s.
• Ignition is on.
DTC P0336
• Ignition is on.
Conditions for Setting the DTCs
DTC P0315
• The CKP system variation values are not stored in the ECM memory.
• The enable counter equals 0.
DTC P0335
• The ECM determines there is no signal from the CKP sensor.
DTC P0336
• The ECM determines there is no signal from the CKP sensor for more than 0.5 seconds.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–129
Page 6C4-2–129
Conditions for Clearing the DTCs
The CKP Sensor Circuit DTCs are Type B DTCs. Refer to 1.5 Diagnostic Trouble Codes for action taken when a Type B
DTC sets and conditions for clearing a Type B DTC.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the Crankshaft
Position (CKP) Sensor System.
• The following conditions may cause a CKP Sensor Circuit to set:
• Poor connections / terminal tension at the sensor.
• Crankshaft reluctor wheel damage or improper installation.
• The sensor coming in contact with the reluctor wheel.
• Excess crankshaft end play will cause the CKP Sensor reluctor wheel to move out of alignment with the CKP
sensor. This could result in any one of the following:
• The engine may not start.
• The engine may start and then stall.
• Erratic performance.
• If the crankshaft rotates backwards with the ignition switched on, DTC P0336 may set.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• Refer to 2 Wiring Diagrams and Connector Charts to aid in the diagnosis procedures.
Diagnostic Table for the CKP Sensor Circuit DTCs
Step Action Value(s) Yes No
1 Has the Diagnostic System Check been performed?
– Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 Does the engine start and continue to run? – Go to Step 3 Go to Step 4
3 1 Observe the Freeze Frame / Failure Record for
this DTC.
2 Switch off the ignition for 30 seconds.
3 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
4 Using Tech 2 select:
Engine / Diagnostic Trouble Codes / Read DTC
Information.
Does P0315, P0335 or P0336 fail this ignition cycle? – Go to Step 4
Refer to Additional
Information in this
section
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–130
Page 6C4-2–130
Step Action Value(s) Yes No
4
Before proceeding, remove fuses F34
and F35 for the ignition coil and fuel
injector feed circuits to prevent personal
injury from engine rotation, sparks, and
excessive engine fuelling.
1 Switch off the ignition.
2 Raise the vehicle and support on safety stands,
refer to 00 Warnings, Cautions and Notes.
3 Disconnect the CKP Sensor wiring connector.
4 Switch on the ignition with the engine not running.
5 Connect a test lamp between the CKP Sensor
ignition feed circuit and the ECM housing.
Is the test lamp illuminated? – Go to Step 5 Go to Step 8
5 Connect the test lamp between the CKP sensor ignition
feed circuit and the CKP sensor low reference circuit.
Is the test lamp illuminated? – Go to Step 6 Go to Step 9
6 1 Switch off the ignition.
2 Disconnect the ECM wiring connector.
3 Using a digital multimeter, measure the resistance
on the signal circuit.
Does the multimeter display less than
5 ohms Go to Step 10 Go to Step 7
7 Test the CKP sensor signal circuit for a short to ground,
high resistance, open circuit, or short to voltage fault
condition. Refer to 12P Wiring Diagrams for information
on electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 14 Go to Step 13
8 Test the CKP sensor ignition feed circuit for a short to
ground, high resistance or an open circuit fault
condition. Refer to 12P Wiring Diagrams for information
on electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 14 Go to Step 13
9 Test the CKP sensor low reference circuit for a high
resistance, open circuit, or short to voltage fault
condition. Refer to 12P Wiring Diagrams for information
on electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 14 Go to Step 13
10 Remove the CKP Sensor and visually inspect the CKP
Sensor for the following conditions:
• Physical damage.
• Loose or improper installation.
• Wiring routed too closely to secondary ignition
components.
• Poor connections / terminal tension at the sensor.
Was any fault found and rectified? – Go to Step 14 Go to Step 11
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–131
Page 6C4-2–131
Step Action Value(s) Yes No
11 Visually inspect the CKP Sensor reluctor wheel for
damage, refer to 6A4 Engine Mechanical – GEN IV V8.
Was any fault found and rectified? – Go to Step 14 Go to Step 12
12 Replace the CKP sensor. Refer to 6C4-3 Engine
Management – GEN IV V8 – Service Operations.
Was the repair completed? – Go to Step 14 –
13 Replace the ECM. Refer to 6C4-3 Engine
Management – GEN V8 – Service Operations.
Was the repair completed? – Go to Step 14 –
14 1 Using Tech 2, clear the DTCs.
2 Switch Off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
Does DTC P0315, P0335 or P0336 fail this ignition
cycle? – Go to Step 16 Go to Step 15
15 Using Tech 2, select the DTC display function.
Are there any DTCs displayed? –
Go to the
appropriate DTC
Table System OK
16 Important:
The crankshaft position variation learn procedure may
have to be repeated up to five times before procedure is
learned
Perform the crankshaft position system variation learn
procedure. Refer to CKP system variation learn
procedure.
Does the scan tool display learned this ignition Go to step 18 Go to step 17
17 If the system variation learn procedure cannot be
performed successfully, inspect for the following
conditions and correct as necessary:
• Worn crankshaft main bearings
• A damaged reluctor wheel
• excessive crankshaft run out
• A damaged crankshaft
• Interference in the signal circuit of the CKP sensor
and the reluctor wheel
• The ignition switch is in the ON position until the
battery is drained.
• If the power supply to the ECM fails with the
ignition ON, the ECM may erase the stored value
and set the DTC P0315
Did you complete the inspection? Go to step 18
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–132
Page 6C4-2–132
Step Action Value(s) Yes No
18 • Clear the DTCs with Tech 2.
• Turn off the ignition.
• Start the engine
• Operate the vehicle within the conditions for
running the DTC as specified in the supporting
text.
Did the DTC fail this ignition? Go to step 16 Go to step 19
19 Observe the capture info with Tech 2.
Are there any DTCs stored?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–133
Page 6C4-2–133
6.16 DTC P0324, P0325, P0326, P0327, P0328,
P0330, P0332, P0333
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0324 – Knock Sensor (KS) Module Performance
• DTC P0325 – Knock Sensor (KS) Circuit Bank 1
• DTC P0326 – Knock Sensor (KS) Performance Bank 1
• DTC P0327 – Knock Sensor (KS) Circuit Low Frequency Bank 1
• DTC P0328 – Knock Sensor (KS) Circuit High Frequency Bank 1
• DTC P0330 – Knock Sensor (KS) Circuit Bank 2
• DTC P0332 – Knock Sensor (KS) Circuit Low Frequency Bank 2
• DTC P0333 – Knock Sensor (KS) Circuit High Frequency Bank 2
Circuit Description
The ECM supplies the ground to the Knock Sensor (KS) low reference circuit. The KS produces a signal voltage when an
engine spark knock is detected. The amplitude and the frequency of the signal voltage produced are proportional to the
level of vibration created by the spark knock. When the ECM detects an excessive spark knock, it retards the ignition
timing until the spark knock stops.
To differentiate between a normal engine vibration and the vibration created by a spark knock, the ECM samples the KS
signal under different engine speeds and load condition. The ECM uses these samples to determine maximum and
minimum KS signal voltage produced when the engine is running under normal conditions.
The ECM incorporates a filter which processes the signal for use by other parts of the ECM.
If the ECM determines that there is a fault with the knock control system, a knock sensor system DTC will set.
DTC P0324 only
Test One
The ECM performs the following:
1 Turns off the knock sensor signal circuits.
2 Applies different test signals to the ECM internal KS circuitry.
3 Verifies each test signal output response is within range.
4 If the ECM detects any of the tested signals are not within the normal range, DTC P0324 sets.
Test Two
The ECM performs the following:
1 Turns off the knock sensor signal circuits.
2 Tests for any output response when no test signals are applied.
3 If the ECM detects an output response, DTC P0324 sets.
Test Three
1 Turns off the knock sensor signal circuits.
2 Generates an internal test pulse then monitors the return signal.
3 If the return test pulse is less than a calibrated threshold, DTC P0324 sets.
DTC P0324 sets if the ECM detects an incorrect response to the ECM internal KS circuitry tests.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–134
Page 6C4-2–134
Conditions for Running the DTC
The DTCs run continuously once the following conditions are met:
DTC P0324
Condition One
Runs continuously once the following conditions are met:
• The ECM is controlling the ignition spark.
• The engine speed is less than 2,300 rpm and steady.
• The volumetric efficiency is steady.
Condition Two
Runs continuously once the following conditions are met:
• The ECM is controlling the ignition spark.
• The engine speed is 1,000 – 4,000 rpm.
• The engine coolant temperature is greater than 60° C.
• The volumetric efficiency is steady.
Condition Three
Runs continuously once the following conditions are met:
• The ECM is controlling the ignition spark.
• The engine speed is less than 2,300 rpm and steady.
• The engine coolant temperature is greater than 40° C.
• The volumetric efficiency is steady.
DTC P0325
Run continuously once the following conditions are met:
• The engine run time is greater than 10 seconds.
• The ignition voltage is greater than 10.0 V.
DTC P0326
Run continuously once the following conditions are met:
• Engine speed is greater than 500 RPM.
• MAP is 55 kPa or greater.
• No active TP DTCs.
DTC P0327
Run continuously once the following conditions are met:
• There is no ECT or TP sensor DTCs set.
• The engine speed is between 1500 and 3000 RPM.
• ECT is greater than 60°C.
• The engine run time is greater than 10 seconds.
• The MAP is less than 45 kPa.
• The ignition voltage is greater than 10.0 V.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–135
Page 6C4-2–135
DTC P0328
Run continuously once the following conditions are met:
• The ECM controls the ignition spark.
• Engine speed is greater than 2,000 rpm and steady.
• The engine coolant temperature is greater than 60°C.
• The volumetric efficiency is steady.
DTC P0330
Run continuously once the following conditions are met:
• The engine run time is greater than 10 seconds.
• The ignition voltage is greater than 10.0 V.
DTC P0332
• There is no ECT or TP sensor DTCs set.
• The engine speed is between 1500 and 3000 RPM.
• ECT is greater than 60°C.
• The engine run time is greater than 10 seconds.
• The MAP is less than 45 kPa.
• The ignition voltage is greater than 10.0 V.
DTC P0333
Run continuously once the following conditions are met:
• The ECM controls the ignition spark.
• Engine speed is greater than 2,000 rpm and steady.
• The engine coolant temperature is greater than 60°C.
• The volumetric efficiency is steady.
Conditions for Setting the DTC
DTC P0324
The ECM detects an incorrect response to an internal ECM KS circuitry test.
DTC P0325
Knock sensor voltage less than 0.05 volts or greater than 4.95 volts.
DTC P0326
The ECM detects overactivity of the Knock Sensor.
DTC P0327
The ECM detects that the KS activity is insufficient.
DTC P0328
The ECM detects the KS signal voltage is greater than the maximum KS signal normal range.
DTC P0330
Knock sensor voltage less than 0.05 volts or greater than 4.95 volts.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–136
Page 6C4-2–136
DTC P0332
The ECM detects that the KS activity is insufficient.
DTC P0333
The ECM detects the KS signal voltage is greater than the maximum KS signal normal range.
Conditions for Clearing the DTC
• The Knock Sensor System DTCs are Type B DTCs. Refer to 1.5 Diagnostic Trouble Codes for action taken when
a Type B DTC sets and conditions for clearing Type B DTC.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the Knock Sensor System.
• Preconditions for running knock sensor circuit DTCs requires that DTC P0324 has ran and passed. Therefore, the
diagnostic table for the knock sensor circuit DTCs is developed with the assumption the ECM internal KS circuitry is
functioning correctly.
• Excessive engine mechanical noise or engine knocking condition may trigger knock sensor circuit DTCs.
• The knock sensor must be tightened correctly. Refer to Section 6C4-3 Engine Management – GEN IV V8 – Service
Operations.
• The mounting between the knock sensor and engine must be free of burrs, casting flash and foreign material.
• The knock sensor head must be clear from hoses, brackets and engine wiring.
• If the knock sensor lead is damaged in any way, the sensor must be replaced.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
Refer to 2 Wiring Diagrams and Connector Charts to assist with the diagnosis procedures.
Test Description
The following numbers refer to the step numbers in the diagnostic chart:
3 This DTC indicates an internal ECM problem.
Diagnostic Table for the Knock Sensor and Circuit DTCs
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Observe the Freeze Frame / Failure Record for this DTC.
2 Switch Off the ignition for 30 seconds.
3 Operate the vehicle within the conditions for running the DTC or
within the conditions in the Freeze Frame / Failure Records.
4 Using Tech 2 select:
Engine / Diagnostic Trouble Codes / Read DTC Information.
Does DTC P0325 fail this ignition cycle? Go to Step 8 Go to Step 3
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–137
Page 6C4-2–137
Step Action Yes No
3 1 Observe the Freeze Frame / Failure Record for this DTC.
2 Switch Off the ignition for 30 seconds.
3 Operate the vehicle within the conditions for running the DTC or
within the conditions in the Freeze Frame / Failure Records.
4 Using Tech 2 select:
Engine / Diagnostic Trouble Codes / Read DTC Information.
Does DTC P0327 or P0332 fail this ignition cycle? Go to Step 4
Refer to Additional
Information in this
section
4 Test the appropriate KS signal circuit for a short to ground, high
resistance, short to voltage, or open circuit fault condition. Refer to
12P Wiring Diagrams for information on electrical fault diagnosis.
Was any fault found and rectified? Go to Step 9 Go to Step 5
5 Test the appropriate KS low reference circuit for a short to ground,
high resistance, short to voltage, or open circuit fault condition. Refer
to 12P Wiring Diagrams for information on electrical fault diagnosis.
Was any fault found and rectified? Go to Step 9 Go to Step 6
6 Check the appropriate KS for the following fault condition. Refer to
6C4-3 Engine Management – GEN IV V8 – Service Operations.
• incorrect KS resistance value,
• incorrect KS attaching bolt torque value,
• burrs, casting flash or foreign material between the knock sensor
and engine,
• hoses, brackets or engine wiring touching the KS, and
• damaged KS wiring harness.
Was any fault found and rectified? Go to Step 9 Go to Step 7
7 Replace the appropriate KS. Refer to 6C4-3 Engine Management –
GEN IV V8 – Service Operations.
Was the repair completed? Go to Step 9 –
8 Replace the ECM. Refer to 6C4-3 Engine Management – GEN IV V8
– Service Operations.
Was the repair completed? Go to Step 4 –
9 1 Using Tech 2, clear the DTCs.
2 Switch Off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC or
within the conditions in the Freeze Frame / Failure Records.
Does DTC P0325 fail this ignition cycle? Go to Step 2 Go to Step 10
10 Using Tech 2, select the DTC display function.
Are there any DTCs displayed?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–138
Page 6C4-2–138
6.17 DTC P0340, P0341
This diagnostic procedure supports the following DTCs:
• DTC P0340 - Camshaft position sensor no signal
• DTC P0341 - Camshaft Position Sensor Circuit Performance
Circuit Description
The Engine Control Module (ECM) provides a 12 volt power supply to the CMP sensor as well as a ground and a signal
circuit.
The CMP sensor is a Hall Effect switch. In conjunction with a 1X reluctor wheel, the CMP sensors provide a signal to the
ECM. The ECM uses this signal to determine the position of the camshaft.
The ECM compares the CMP signal voltage to the number of crankshaft revolutions. A CMP sensor DTC sets if the ECM
detects a fault condition in the CMP sensor circuits.
Conditions for Running the DTCs
The engine is running.
Conditions for Setting the DTCs
DTC P0340
The ECM cannot detect a signal from the CMP.
DTC P0341
The ECM detects a signal from the CMP sensor signal circuit and the sensor signal range is not within the predetermined
parameter or the when the CMP sensor does not correlate with the crankshaft position.
Conditions for Clearing the DTCs
The CMP sensor circuit DTCs are Type B DTCs. Refer to 1.5 Diagnostic Trouble Codes for action taken when a Type B
DTC sets and conditions for clearing a Type B DTC.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the Camshaft
Position (CMP) Sensor System.
• The following conditions may cause CMP sensor circuit DTCs to set:
• Poor connections / terminal tension at the sensor.
• Camshaft reluctor wheel damage or improper installation.
• The sensor coming in contact with the reluctor wheel.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• Refer to 2 Wiring Diagrams and Connector Charts to aid in the diagnosis procedures.
Test Description
The following numbers refer to the step numbers in the diagnostic chart:
3 Tests the signal circuit of the CMP sensor.
4 Measures the integrity of the CMP sensor low reference circuit. Removal of the ECM Fuse 29 enables the ECM to
power down completely prior to the test procedure.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–139
Page 6C4-2–139
Diagnostic Table for the CMP Sensor Circuit DTCs
Step Action Value(s) Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Observe the Freeze Frame / Failure Record for
this DTC.
2 Switch off the ignition for 30 seconds.
3 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
4 Using Tech 2 select:
Engine / Diagnostic Trouble Codes / Read DTC
Information.
Does P0340, P0341fail this ignition cycle? Go to Step 3
Refer to Additional
Information in this
section
3 1 Switch off the ignition.
2 Disconnect the CMP sensor wiring connector.
3 Switch on the ignition with the engine not running.
4 Using a digital multimeter, measure the voltage
between the signal circuit of the CMP sensor and
the ECM housing.
Does the multimeter indicate battery voltage? 11 – 14 V Go to Step 4 Go to Step 7
4 1 Switch off the ignition.
2 Remove ECM Fuse 29 from the engine
compartment fuse and relay panel assembly.
3 Using a digital multimeter, measure the resistance
between the CMP sensor low reference circuit and
the ECM housing.
Is the resistance less than the specified value? 5 Ω Go to Step 5 Go to Step 8
5 Test the signal circuit of the CMP sensor for a high
resistance, open circuit, short to ground or short to
voltage fault condition. Refer to 12P Wiring Diagrams
for information on electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 11 Go to Step 6
6 Perform the following CMP sensor inspection:
• Inspect the sensor wiring harness for conditions
that may induce electromagnetic interference,
refer to 4.2 Intermittent Fault Conditions.
• Inspect the sensor for incorrect sensor installation
or incorrect attaching bolt torque value, refer to
6C4-3 Engine Management – GEN IV V8 –
Service Operations.
• Inspect the CMP sensor reluctor wheel for
damage or conditions causing misalignment.
Was any fault found and rectified? – Go to Step 11 Go to Step 9
7 Test the CMP sensor 5 volts reference circuit for a high
resistance, open circuit, short to voltage or short to
ground fault condition. Refer to 12P Wiring Diagrams for
information on electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 11 Go to Step 10
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–140
Page 6C4-2–140
Step Action Value(s) Yes No
8 Test the CMP sensor low reference circuit for a high
resistance, open circuit, or short to voltage fault
condition. Refer to 12P Wiring Diagrams for information
on electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 11 Go to Step 10
9 Replace the CMP Sensor, refer to 6C4-3 Engine
Management – GEN IV V8 – Service Operations.
Was the repair completed? – Go to Step 11 –
10 Replace the ECM, refer to 6C4-3 Engine Management –
GEN IV V8 – Service Operations.
Was the repair completed? – Go to Step 11 –
11 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
Do any of the CMP Sensor Circuit DTCs fail this ignition
cycle? – Go to Step 2 Go to Step 12
12 Using Tech 2, select the DTC display function.
Are there any DTCs displayed? –
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–141
Page 6C4-2–141
6.18 DTC P0351, P0352, P0353, P0354, P0355,
P0356, P0357, P0358
DTC Description
This diagnostic procedure covers the following DTCs:
• DTC P0351 – Ignition 1 Control Circuit
• DTC P0352 – Ignition 2 Control Circuit
• DTC P0353 – Ignition 3 Control Circuit
• DTC P0354 – Ignition 4 Control Circuit
• DTC P0355 – Ignition 5 Control Circuit
• DTC P0356 – Ignition 6 Control Circuit
• DTC P0357 – Ignition 7 Control Circuit
• DTC P0358 – Ignition 8 Control Circuit
Circuit Description
The EFI Relay applies positive voltage to the ignition voltage circuit of the ignition coil and the ignition coil ground circuits
are directly connected to ground.
The ECM applies control voltage to the control circuit of the ignition coil during the calculated dwell period that allows
current flow to the ignition coil primary winding to generate a magnetic flux field. At the appropriate firing point, the ECM
interrupts the control voltage applied to the ignition coil.
Interruption of voltage applied to the control circuit of the ignition coil primary winding induces the transfer of electrical
energy from the ignition coil primary winding to the ignition coil secondary winding, which triggers the ignition coil to
produce a spark at the spark plug.
An ignition coil control circuit DTC sets if the ECM detects a fault condition in the control circuit of an ignition coil.
Conditions for Running the DTCs
The ignition voltage is between 10.0 and 18.0 volts.
Conditions for Setting the DTCs
The ECM detects the Ignition Control circuit is grounded, open or shorted to voltage.
Conditions for Clearing the DTCs
The ignition control circuit DTCs are Type B DTCs. Refer to 1.5 Diagnostic Trouble Codes for action taken when Type B
DTCs set and conditions for clearing Type B DTCs.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the Ignition Control
(IC) System.
• The ignition coils for each bank of the engine are fused separately. If all DTCs for a single bank are set, there may
be a fault in one of the ignition supply circuits.
• There is a ground connection shared between the four ignition coils on each bank of the engine. If all DTCs for a
single bank are set, there may be a fault in one of the ground circuits.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• Refer to 2 Wiring Diagrams and Connector Charts to aid in the diagnosis procedures.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–142
Page 6C4-2–142
Test Descriptions
The following numbers refer to the step numbers in the diagnostic chart:
3 If DTCs P0351, P0353, P0355, and P0357, or P0352, P0354, P0356, and P0358 are set at the same time, this
indicates that there is a fault with a shared circuit.
Diagnostic Table for the Ignition Control Circuit DTCs
Step Action Value(s) Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Observe the Freeze Frame / Failure Record for
this DTC.
2 Switch off the ignition for 30 seconds.
3 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
4 Using Tech 2 select:
Engine / Diagnostic Trouble Codes / Read DTC
Information.
Does DTC P0351, P0352, P0353, P0354, P0355,
P0356, P0357 or P0358 fail this ignition cycle? – Go to Step 3
Refer to Additional
Information in this
section.
3 Are DTCs P0351, P0353, P0355, and P0357, or P0352,
P0354, P0356, and P0358 set at the same time? – Go to Step 6 Go to Step 4
4 1 Switch off the ignition.
2 Disconnect the appropriate ignition coil electrical
harness connector.
3 Connect a test lamp between the applicable
ignition control circuit and the ECM housing.
4 Crank the engine.
Does the test lamp flash on and off? – Go to Step 6 Go to Step 5
5 Test the IC control circuit for a short to ground, an open
circuit, high resistance or short to voltage fault condition.
Refer to 12P Wiring Diagrams for information on
electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 9 Go to Step 8
6 Test the IC ground circuit for an open circuit or high
resistance fault condition. Refer to 12P Wiring Diagrams
for information on electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 9 Go to Step 7
7 Replace the appropriate ignition coil, refer to 6C4-3
Engine Management – GEN IV V8 – Service
Operations.
Was the repair completed? – Go to Step 9 –
8 Replace the ECM, refer to 6C4-3 Engine Management –
GEN IV V8 – Service Operations.
Was the repair completed? – Go to Step 9 –
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–143
Page 6C4-2–143
Step Action Value(s) Yes No
9 1 Using Tech 2, clear the DTCs.
2 Switch Off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
Do any of the ignition control circuit DTCs fail this
ignition cycle? – Go to Step 2 Go to Step 10
10 Using Tech 2, select the DTC display function.
Are there any DTCs displayed? –
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–144
Page 6C4-2–144
6.19 DTC P0420 or P0430
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0420 Catalyst System Low Efficiency Bank 1
• DTC P0430 Catalyst System Low Efficiency Bank 2
Circuit Description
To maintain a reasonably low emission level of hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx)
a 3-way catalytic converter (TWC) is used. The catalyst within the converter promotes a chemical reaction that oxidizes
the HC and CO present in the exhaust gas. This reaction converts the gases into harmless water vapour and carbon
dioxide. The catalyst also reduces the NOx , converting the NOx into nitrogen. The engine control module (ECM)
monitors this process using the post catalyst heated oxygen sensor (Heated O2 Sensor) signal. The post-catalyst Heated
O2 Sensor located in the exhaust stream after the TWC, produces an output signal that indicates the oxygen storage
capacity of the catalyst. The oxygen storage capacity (OSC) determines the ability of the catalyst to convert the exhaust
emissions effectively. If the catalyst is functioning correctly, the post-catalyst Heated O2 Sensor signal will be far less
active than the signal produced by the pre-catalyst Heated O2 Sensor.
To determine OSC, the ECM commands a rich air/fuel mixture until all oxygen is removed from the catalyst. The ECM
then commands a lean air/fuel mixture and monitors the rear heated oxygen sensors to calculate the oxygen storage
capacity. The catalyst is operated in this mode until one of the following conditions occur:
• The oxygen stored in the catalyst exceeds a calibrated threshold, which is determined from the rear Heated O2
Sensor signal.
• The rear Heated O2 Sensor indicates the catalyst to be completely saturated with oxygen, which is determined from
the rear Heated O2 Sensor signal.
If the ECM detects the average OSC is less than a threshold, this DTC sets. This indicates that the TW C oxygen storage
capacity is below a threshold considered acceptable.
Conditions for Running the DTC
• Before the ECM can report, the following no active codes to be found for VSS, EGR Control, Throttle, Purge
Control, Purge Circuit, Oxygen Sensor, Misfire, IAT, MAP, Injectors, EST Control, Coolant, Crank Sensor, Cam
Sensor, Air Flow IAC or fuel trim
• The engine speed is more than or equal to 900RPM.
• The air flow into the engine is between 7.0 – 16.0 g/s and not changing more than 3.0 g/s.
• The engine intake air temperature (IAT) at engine start-up is more than –30° C.
• The engine is operating for more than 10 minutes.
• The engine is operating in Closed Loop.
• The calculated TWC temperature is between 500 – 750° C and steady.
• The above conditions exist for approximately 17 minutes.
• DTCs P0420 and P0430 run once a drive cycle. The ECM will attempt to run this diagnostic up to 6 times a drive
cycle.
Conditions for Setting the DTC
The ECM determines that the catalyst efficiency has degraded below a calibrated threshold for more than 4 seconds.
Action Taken When the DTC Sets
• The control module activates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the
diagnostic runs and fails.
• The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic
fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the
second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The
control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–145
Page 6C4-2–145
Conditions for Clearing the DTC
The Catalyst Efficiency DTCs are type A DTCs. Refer to 1.5 Diagnostic Trouble Codes for action taken when a Type A
sets and the conditions for clearing Type B DTCs.
P0420 or P0430 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been completed? Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 Are any other DTCs set?
Go to the
appropriate DTC
Table Go to Step 3
3
Inspect for the following conditions:
• The catalytic converter is an original equipment part.
• Inspect the exhaust system for leaks, damage, loose or missing
hardware in the area from the converter to the heated oxygen
sensor 2.
• The Heated O2 Sensors are secure and the wiring is not
damaged or contacting the exhaust.
Did you find and correct the condition? Go to Step 5 Go to Step 4
4
NOTE
Before replacing the 3-way catalytic converter (TWC),
correct any conditions that may have damaged the
converter.
Replace the catalytic converter. Refer to the appropriate procedure in
8B Exhaust System.
Did you complete the replacement? Go to Step 5 —
5 1 Using Tech 2, clear the DTC/s.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Does P0420 or P0430 fail this ignition cycle? Go to Step 2 Go to Step 6
6 Using Tech 2, select the DTC display function.
Are there any DTCs displayed?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, clear all DTCs and verify correct operation
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–146
Page 6C4-2–146
6.20 DTC P0443
DTC Description
This diagnostic procedure supports the following DTC
• DTC P0443 – Evaporative Emission Control System Purge Solenoid Circuit Malfunction
Circuit Description
Battery voltage is supplied to the Evaporative Emission Control System (EVAP) purge solenoid relay coil via the EFI
relay. The Engine Control Module (ECM) controls the EVAP purge solenoid by grounding the control circuit via an
internal switch called a driver. The driver has a fault line, which the ECM monitors. If the fault detection circuit senses a
voltage other than what the ECM expected, the fault line status changes, causing DTC P0443 to set.
Conditions for Running the DTC
• The ignition voltage is between 10.0 and 18.0 volts.
• The engine speed is greater than 400 RPM.
Conditions for Setting the DTC
The ECM detects that the commanded state of the circuit and the actual state of the circuit does not match.
Conditions for Clearing the DTC
The EVAP Canister Purge Solenoid Control Circuit DTC is a Type B DTC. Refer to 1.5 Diagnostic Trouble Codes for
action taken when a Type B DTC sets and conditions for clearing a Type B DTC.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the Evaporative
Emission system.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• Refer to 2 Wiring Diagrams and Connector Charts to aid in the diagnosis procedures.
Diagnostic Table for the Evaporative Emission Control System Purge Control Circuit DTCs
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Using Tech 2, observe the Freeze Frame / Failure Records for
this DTC.
2 Switch off the ignition for 30 seconds.
3 Operate the vehicle within the conditions for running the DTC or
within the conditions in the Freeze Frame / Failure Records.
4 Using Tech 2 select:
Engine / Diagnostic Trouble Codes / Read DTC Information.
Does DTC P0443 fail this ignition cycle? Go to Step 3
Refer to Additional
Information in this
section
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–147
Page 6C4-2–147
Step Action Yes No
3 1 Switch off the ignition.
2 Disconnect the EVAP purge solenoid wiring connector.
3 Switch on the ignition with the engine not running.
4 Using Tech 2, command the EVAP purge solenoid to 0%.
5 Connect a test lamp between the EVAP purge solenoid ignition
voltage circuit and the EVAP purge solenoid control circuit.
Does the test lamp illuminate? Go to Step 6 Go to Step 4
4 Using Tech 2, command the EVAP purge solenoid to 50%.
Does the test lamp illuminate or pulse? Go to Step 8 Go to Step 5
5 Connect a test lamp between the EVAP purge solenoid ignition
voltage circuit and a known ground.
Does the test lamp illuminate? Go to Step 6 Go to Step 7
6 Test the EVAP purge solenoid control circuit for an open circuit, short
to ground, high resistance, or short to voltage fault condition. Refer to
12P Wiring Diagrams for information on electrical fault diagnosis.
Was any fault found and rectified? Go to Step 10 Go to Step 9
7 Repair the open circuit, short to ground, high resistance, or short to
voltage fault condition in the EVAP purge solenoid ignition voltage
circuit. Refer to 12P Wiring Diagrams for information on electrical
wiring repair procedures.
Was the repair completed? Go to Step 10 –
8 Replace the EVAP purge solenoid. Refer to 6C4-3 Engine
Management – GEN IV V8 – Service Operations.
Was the repair completed? Go to Step 10 –
9 Replace the ECM. Refer to 6C4-3 Engine Management GEN IV V8 –
Service Operations.
Was the repair completed? Go to Step 10 –
10 1 Using Tech 2, clear the DTCs.
2 Switch Off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC or
within the conditions in the Freeze Frame / Failure Records.
Does P0443 fail this ignition cycle? Go to Step 2 Go to Step 11
11 Using Tech 2, select the DTC display function.
Are there any DTCs displayed?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–148
Page 6C4-2–148
6.21 DTC P0461, P0462 and P0463
DTC Description
This diagnostic procedure covers the following DTCs:
• DTC P0461 – Fuel Level Sensor Range / Performance
• DTC P0462 – Fuel Level Sensor Low Voltage
• DTC P0463 – Fuel Level Sensor High Voltage
Circuit Description
The fuel level sensor changes resistance based on the fuel level in the fuel tank. The Engine Control Module (ECM)
monitors changes in the resistance of the sensor to determine the fuel level. This information is then sent to the
instrument cluster via the Class 2 serial data circuit.
When the fuel tank is full, the sensor resistance is high, and the ECM senses high signal voltage. When the fuel tank is
empty, the sensor resistance is low, and the ECM senses a low signal voltage.
When the ECM senses a signal voltage outside the normal operating range of the sensor, a Fuel Level Sensor DTC will
set.
Conditions for Running the DTCs
• The ignition is on.
Conditions for Setting the DTCs
DTC P0461
The ECM detects that more than 200 km have been accumulated and the fuel level in the fuel tank has not changed by at
least 3.0 litres.
DTC P0462 and DTC P0463
The ECM detects that the fuel level signal is outside the predetermined range.
Conditions for Clearing the DTCs
The fuel level sensor circuit DTCs are Type C DTCs. Refer to 1.5 Diagnostic Trouble Codes for action taken when Type
C DTCs set and conditions for clearing Type C DTCs.
Additional Information
• Refer to Section 12C Instrumentation for further information on the Fuel Gauge System.
• Depending on the current fuel level, it may be difficult to locate a malfunctioning sending unit. The malfunction may
only occur when the fuel level is full or near empty. The fuel sending unit may need to be removed for further
diagnosis. A fuel level sensor that has an intermittent condition may cause a DTC to set. Remove the fuel level
sensor to test the resistance of the sensor, refer to Section 8A1 Fuel System. The resistance of the sensor should
change from 40 to 250 ohms as the float arm is moved from the empty to full positions. Replace the sensor if the
resistance did not change or is out of range.
• The following may occur with a fuel level sensor DTC set:
• The vehicle fuel gauge displays empty.
• The Instrument Multi-Function Display (MFD) displays a message.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• Refer to 2.1 Wiring Diagrams to aid in the diagnosis procedures.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–149
Page 6C4-2–149
Diagnostic Table for the Fuel Tank Sensor DTCs
Step Action Value(s) Yes No
1 Has the Diagnostic System Check been performed?
– Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Observe the Freeze Frame / Failure Record for
this DTC.
2 Switch Off the ignition for 30 seconds.
3 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
4 Using Tech 2 select:
Engine / Diagnostic Trouble Codes / Read DTC
Information.
Does DTC P0461, P0462, or P0463 fail this ignition
cycle? – Go to Step 3
Refer to Additional
Information in this
section
3 1 Switch off the ignition.
2 Disconnect the fuel level sensor wiring connector.
3 Switch on the ignition with the engine not running.
4 Using a digital multimeter, measure the voltage
between the fuel level sensor signal circuit and the
ECM housing.
Is the voltage within the specified range? 4.8 – 5.2 V Go to Step 4 Go to Step 5
4 1 Switch off the ignition.
2 Remove ECM Fuse 29 from the engine
compartment fuse and relay panel assembly.
3 Using a digital multimeter, measure the resistance
between the fuel level sensor low reference circuit
and the ECM housing.
NOTE
Install the ECM Fuse 29 to the engine
compartment fuse and relay panel assembly
after completing this test.
Is the resistance less than the specified value? 5 Ω Go to Step 7 Go to Step 6
5 Test the fuel level sensor signal circuit for a high
resistance, open circuit, short to ground or short to
voltage fault condition. Refer to 12P Wiring Diagrams
for information on electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 9 Go to Step 8
6 Test the fuel level sensor low reference circuit for a high
resistance, open circuit, short to ground or short to
voltage fault condition. Refer to 12P Wiring Diagrams
for information on electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 9 Go to Step 8
7 Replace the fuel level sensor. Refer to 8A1 Fuel
Systems.
Was the repair completed? – Go to Step 9 –
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–150
Page 6C4-2–150
Step Action Value(s) Yes No
8 Replace the ECM. Refer to 6C4-3 Engine Management
GEN IV V8 – Service Operations.
Was the repair completed? – Go to Step 9 –
9 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
Do any fuel level sensor DTCs fail this ignition cycle? – Go to Step 2 Go to Step 10
10 Using Tech 2, select the DTC display function.
Are there any DTCs displayed? –
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–151
Page 6C4-2–151
6.22 DTC P0480, P0481
DTC Description
This diagnostic procedure covers – DTC P0480 P0481 Cooling Fan Circuit malfunction.
Circuit Description
The EFI Relay applies ignition positive battery voltage to the engine cooling fan relay. Using a device called a driver, the
ECM applies ground to the engine cooling fan relay control signal circuit to provide cooling fans. The ECM monitors the
driver feedback circuit to determine if the control circuit is open, shorted to ground or shorted to a positive voltage. DTC
P0480, P0481 sets if the ECM detects a fault condition in the engine cooling fan relay control circuit.
Conditions for Running the DTCs
• The ignition voltage is between 10–18 volts.
• The engine speed is more than 400 RPM.
Condition for Setting the DTCs
The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match.
Conditions for Clearing DTCs
The cooling fan high speed relay circuit DTCs are Type B DTCs. Refer to 1.5 Diagnostic Tr ouble Codes for action taken
when Type B DTCs set and conditions for clearing Type B DTCs.
Additional Information
• Refer to Section 6B4 Engine Cooling – GEN IV V8 for details of the engine cooling fan operation.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Refer to 2 Wiring Diagrams and Connector Charts to aid in the diagnosis procedures.
Diagnostic Table for the Cooling Fan High Speed Relay Circuit DTCs
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Using Tech 2, observe the Freeze Frame / Failure Records for
this DTC.
2 Switch off the ignition for 30 seconds.
3 Operate the vehicle within the conditions for running the DTC or
within the conditions in the Freeze Frame / Failure Records.
4 Using Tech 2 select:
Engine / Diagnostic Trouble Codes / Read DTC Information.
Does DTC P0480 or P0481 fail this ignition cycle? Go to Step 3
Refer to Additional
Information in this
section
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–152
Page 6C4-2–152
Step Action Yes No
3 1 Switch off the ignition.
2 Remove the engine cooling fan relay from the engine
compartment fuse & relay panel.
3 Connect a test lamp between the cooling fan relay control circuit
and the cooling fan relay ground circuit.
4 Switch on the ignition with the engine not running.
5 Using Tech 2, command the cooling fan relay On and Off.
Does the test lamp turn on and off when commanded? Go to Step 7 Go to Step 4
4 1 Connect a test lamp between the cooling fan relay control circuit
and a known ground.
2 Switch on the ignition with the engine not running.
3 Using Tech 2, command the cooling fan relay On and Off.
Does the test lamp turn on and off when commanded? Go to Step 6 Go to Step 5
5 Test the cooling fan relay 2 control circuit for a high resistance, open
circuit, short to voltage, or short to ground fault condition. Refer to 12P
Wiring Diagrams for information on electrical wiring repair procedures.
Was any fault found and rectified? Go to Step 9 Go to Step 8
6 Repair the high resistance or open circuit fault condition in the cooling
fan relay ground circuit. Refer to 12P Wiring Diagrams for information
on electrical wiring repair procedures.
Was the repair completed? Go to Step 9 –
7 Replace the cooling fan relay.
Was the repair completed? Go to Step 9 –
8 Replace the ECM. Refer to 6C4-3 Engine Management –
GEN IV V8 – Service Operations.
Was the repair completed? Go to Step 9 –
9 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC or
within the conditions in the Freeze Frame / Failure Records.
Does DTC P0480 or P0481 fail this ignition cycle? Go to Step 2 Go to Step 10
10 Using Tech 2, select the DTC display function.
Are there any DTCs displayed?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–153
Page 6C4-2–153
6.23 DTC P0502
DTC Description
This diagnostic procedure covers the following DTC:
• DTC P0502 – Vehicle Speed Sensor Circuit Low Input
Circuit Description
Vehicle speed information is provided to the Engine Control Module (ECM) by the Vehicle Speed Sensor (VSS). The
VSS is an AC voltage generator that is mounted on the transmission and produces an AC voltage of which amplitude and
frequency increases with vehicle speed. The ECM converts the AC voltage into a signal that is a function of vehicle
speed. The ECM supplies the necessary signal to the instrument cluster for speedometer and odometer operation, and to
the Body Control Module (BCM).
Conditions for Running the DTC
DTC P0502
• No MAP sensor, Throttle Position, or TFP manual valve position switch DTCs are set.
• The transmission is not in park or neutral.
• The Throttle Position angle is greater than 15%.
• The engine vacuum is 0 – 105 kPa.
• The engine speed is greater than 3,000 RPM.
• The engine torque is between 40 – 543 Nm.
Conditions for Setting the DTC
DTC P0502
The transmission output speed is less than 150 RPM for at least three seconds.
Conditions for Clearing DTC
The Vehicle Speed Sensor Circuit DTCs are Type B DTCs. refer to 1.5 Diagnostic Trouble Codes for action taken when
a Type B DTC sets and conditions for clearing a Type B DTC.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the vehicle speed
sensor operation.
• Ensure the VSS is correctly torqued to the transmission housing.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• Refer to 2 Wiring Diagrams and Connector Charts to aid in the diagnosis procedures.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–154
Page 6C4-2–154
Diagnostic Table for the Vehicle Speed Sensor Circuit DTCs
Step Action Value(s) Yes No
1 Has the diagnostic system check been performed?
– Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Using Tech 2, observe the Freeze Frame / Failure
Records for this DTC.
2 Switch off the ignition for 30 seconds.
3 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
4 Using Tech 2 select:
Engine / Diagnostic Trouble Codes / Read DTC
Information.
Does DTC P0502 fail this ignition cycle? – Go to Step 3
Refer to Additional
Information in this
section
3 1 Switch off the ignition.
2 Disconnect the wiring connector from the VSS.
3 Using a multimeter, measure the resistance
across the VSS sensor connector pins.
Is the resistance within the specified value? 1,655 –
2,900 Ω Go to Step 4 Go to Step 8
4
To avoid damage to the drive axles,
support the lower control arms in the
normal horizontal position. Do not run
the vehicle in gear with the wheels
hanging down at full travel.
1 Raise the vehicle and support the drive axles with
safety stands. Refer to 0A General Information for
the location of jacking and support points.
2 Connect a multimeter across the VSS pins.
Use the adapters in the connector
adapter kit KM–609 to allow the
multimeter to be viewed from the driver’s
seat. Do not get under the vehicle while it
is running.
3 Start the vehicle.
4 Disable the ABS/TCS system.
5 Select a forward gear.
6 Observe the multimeter reading.
Is the reading greater than the specified value? 0.5 V AC Go to Step 5 Go to Step 6
5 Test both VSS signal circuits for a high resistance, open
circuit, short to ground or short to voltage fault condition.
Refer to 12P Wiring Diagrams for information on
electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 10 Go to Step 9
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–155
Page 6C4-2–155
Step Action Value(s) Yes No
6 Remove the VSS and visually inspect the VSS for the
following conditions:
• Physical damage.
• Loose or improper installation.
• Poor connections / terminal tension at the sensor.
Was any fault found and rectified? – Go to Step 10 Go to Step 7
7 Visually inspect the VSS rotor for damage, refer to the
appropriate transmission section.
Was any fault found and rectified? – Go to Step 10 Go to Step 8
8 Replace the VSS, refer to 6C4-3 Engine Management
GEN IV V8 – Service Operations.
Was the repair completed? – Go to Step 10 –
9 Replace the ECM. Refer to 6C4-3 Engine Management
GEN IV V8 – Service Operations.
Was the repair completed? – Go to Step 10 –
10 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
Do any VSS DTCs fail this ignition cycle? – Go to Step 2 Go to Step 11
11 Using Tech 2, select the DTC display function.
Are there any DTCs displayed? –
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–156
Page 6C4-2–156
6.24 DTC P0506, P0507 P2119
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0506 – Idle Speed Control rpm Too Low
• DTC P0507 – Idle Speed Control rpm Too High
• DTC P2119 – Closed Throttle Position Range / Performance
Circuit Description
The ECM monitors and evaluates the accelerator pedal position (APP) sensors signal voltage along with other sensor
inputs to determine the desired throttle opening. To control the throttle plate movement, the ECM applies a pulse width
modulated (PWM) signal voltage to the throttle actuator motor through the throttle actuator motor control circuits.
• At engine idle speed or when no current is flowing into the throttle actuator motor, a constant force return spring
holds the throttle plate at a constant 7 percent throttle opening position.
• To control the throttle opening, the ECM applies PWM voltage to the throttle actuator motor. The ECM increases
this PWM voltage duty cycle to increase the throttle opening.
• To decrease the throttle opening from the 7 percent rest position, the ECM reverses the polarity of the throttle
actuator motor control circuit then applies a PWM voltage to the throttle actuator motor.
In addition, the ECM monitors the signal voltage applied to the throttle actuator motor control circuit. A TAC motor control
circuit DTC sets if the ECM detects a fault condition in the TAC circuits or motor performance.
Conditions for Running the DTC
The DTCs run continuously once the following conditions are met:
DTC P0506 and P0507
• DTCs P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0220, P0222, P0223 and P0443 are not set.
• The ignition is switched on.
• The vehicle speed is 0 km/h.
• The engine coolant temperature is greater than 60°C.
• The intake air temperature is greater than -10.5°C.
• The volumetric efficiency is less than 35 percent.
• The EVAP purge solenoid is off.
DTC P2119
Runs continuously once the following conditions are met:
• The ignition is switched on.
• The vehicle speed is 0 km/h.
• The engine speed is less than 40 rpm
• The engine coolant temperature is 5 – 60°C.
• The intake air temperature is 5 – 60°C.
• The ignition voltage is greater than 10 V.
The APP is less than 15 percent
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–157
Page 6C4-2–157
Conditions for Setting the DTC
DTC P0506
The actual engine speed is less than the desired idle speed by at least 100 rpm for 10 seconds.
DTC P0507
The actual engine speed is greater than the desired idle speed by at least 200 rpm for 10 seconds or the ECM detects 3
fuel cut-offs due to an engine over speed condition while the engine is idling.
DTC P2119
The ECM determines the throttle plate didn't return to the rest position within 720 milliseconds
Conditions for Clearing the DTC
The TAC motor control circuit DTCs are Type B DTCs refer to 1.5 Diagnostic Trouble Codes for action taken when a
Type B DTC sets and conditions for clearing Type B DTCs.
P2119 is a type C DTC, refer to 1.5 Diagnostic Trouble Codes for action taken when a Type C DTC sets and conditions
for clearing Type C DTCs.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the Throttle Actuator
Control System operation.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• To assist diagnosis, refer to 2 Wiring Diagrams and Connector Charts for the system wiring diagram and connector
charts.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
4 A constant force return spring holds the throttle plate at a constant 7 percent throttle opening position and should
move in either direction under spring pressure and without binding.
8 When the ignition is switched on, the ECM operates the throttle actuator motor to verify the integrity of the TAC
system prior to start up. This can be seen by the momentary flash of the test lamp as the ignition is switched on.
Diagnostic Table for.P0506, P0507 or P2119
Step Action Values Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for
running the DTC.
3 Start the engine.
4 Quickly depress the accelerator pedal to wide-open
throttle then release pedal. Repeat this procedure
several times.
5 Using Tech 2, select the DTC display function.
Does DTC P0506, P0507, P0638, P1551, P2100, P2101,
P2119 or P2176 fail this ignition cycle? Go to Step 3
Refer to Additional
Information in this
Section
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–158
Page 6C4-2–158
Step Action Values Yes No
3 Is DTC P0121, P0122, P0123, P0221, P0222 or P0223
also set?
Refer to the
appropriate DTC
table. Go to Step 4
4 1 Disconnect the throttle actuator wiring connector.
Accidental operation of the TAC motor
while performing throttle plate inspection
may cause severe personal injury. Refer to
6C4-3 Engine Management – GEN IV V8 –
Service Operations, for additional
precautions on throttle body service
procedure.
2 Inspect the throttle plate for the following:
• excessive dirt build-up in the throttle body,
• not in rest position,
• binding open or binding close,
• binding when moving from open to close or
close to open position, and
• free to move open or close without spring
pressure.
Was any fault found and rectified? Go to Step 13 Go to Step 5
5 Inspect the engine for fault conditions that causes
incorrect idle speed. Refer to 4.1 Symptom Diagnosis
Table
Was any fault found and rectified? Go to Step 13 Go to Step 6
6 1 Switch on the ignition with the engine not running.
2 Using a digital multimeter, measure the voltage
between the TAC positive circuit and the ECM
housing.
Does the multimeter display? 2 – 4 V Go to Step 7 Go to Step 9
7 1 Switch on the ignition with the engine not running.
2 Using a digital multimeter, measure the voltage
between the TAC negative control circuit and the
ECM housing.
Does the multimeter display? 2 – 4 V? Go to Step 8 Go to Step 9
8 1 Switch off the ignition.
2 Connect Tool No. J34730-405 injector test lamp
between the positive and negative control circuit of
the TAC.
3 Switch on the ignition for about 5 seconds then
switch off while observing the test lamp.
Does the test lamp illuminate briefly each time the
ignition cycles? Go to Step 11 Go to Step 10
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–159
Page 6C4-2–159
Step Action Values Yes No
9 Test the TAC control circuit that measured outside the
specified value for a high resistance, open circuit, short
to ground or short to voltage fault condition. Refer to
12P Wiring Diagrams for information on electrical fault
diagnosis.
Was any fault found and rectified? Go to Step 13 Go to Step 12
10 Test the positive and negative control circuits of the TAC
for a shorted together fault condition. Refer to 12P Wiring
Diagrams for information on electrical fault diagnosis.
Was any fault found and rectified? Go to Step 13 Go to Step 12
11 Replace the throttle body assembly. Refer to 6C4-3
Engine Management – GEN IV V8 – Service Operations.
Was the repair completed? Go to Step 13 —
12 Replace the ECM. Refer 6C4-3 Engine Management –
GEN IV V8 – Service Operations.
Was the repair completed? Go to Step 13 —
13 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC.
Does any of the TAC motor control circuit DTCs fail this
ignition cycle? Go to Step 2 Go to Step 14
14 Using Tech 2, select the DTC display function
Are there any recorded DTCs?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–160
Page 6C4-2–160
6.25 DTC P0513, P0633, P1629, P1632, P1648,
P1677, P1678, P1679
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0513 – Wrong T r ansponder Key
• DTC P0633 – Immobiliser Function Not Programmed
• DTC P1629 – Immobiliser Fuel Enable Signal Not Received
• DTC P1632 – Immobiliser Fuel Disable Signal Received
• DTC P1648 – Anti-Theft Device – Wr ong Security Code - No Information
• DTC P1677 – Immobiliser Function Not Enabled
• DTC P1678 – Engine Control Module Identification Failed
• DTC P1679 – Immobiliser Environment Identification Failed
Circuit Description
The engine control module (ECM), the Powertrain Interface Module (PIM) and the Body Control Module (BCM) are
integral parts of the vehicle theft deterrent system. The theft deterrent system authenticates the security code
programmed into each of these modules to prevent unauthorised vehicle operation. This authentication process includes
the following steps:
1 At predetermined situations, the BCM sends a security code to the PIM.
2 When the ignition is switched ON, the PIM receives and compares this security code from the BCM against the
security code programmed into the PIM.
3 Once the PIM receives the correct security code from the BCM, it sends a security code to the ECM.
4 The ECM receives and compares this security code from the PIM against the security code programmed into the
ECM.
5 The authentication process is complete once the ECM receives the correct security code from the PIM within the
specified time frame.
6 The ECM allows normal vehicle operation.
NOTE
If any of these authentication processes fail, the
vehicle will not start and DTCs will set. For further
information on the theft deterrent system, refer to
Section 12J Body Control Module.
Conditions for Running the DTC
Conditions for running the DTC are:
• The ignition is switched on.
• The ignition voltage is 10.0 – 16.0 V.
Conditions for Setting the DTC
P0513
The ECM receives an incorrect response from the PIM during the theft deterrent security authentication process.
P0633
An attempt is made to start the engine before the immobiliser function has been programmed into a new PIM.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–161
Page 6C4-2–161
P1629
The ECM has not received a fuel enable password from the body control module (BCM).
P1632
The ECM receives an incorrect response from the PIM during the theft deterrent security authentication process.
P1677
An attempt is made to start the vehicle after the ECM was reset.
P1678
The ECM does not receive a valid response from the PIM when an attempt is made to start the engine.
P1679
The ECM receives a message from the PIM stating that it can't authenticate to the BCM.
Conditions for Clearing the DTC
These DTCs are type B DTCs. Refer to 1.5 Diagnostic Trouble Codes for action taken when a Type B DTC sets and
conditions for clearing Type B DTCs.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the ECM operation.
• Refer to Section 12J Body Control Module for the following information:
• BCM link to PIM, and
• Theft Deterrent System.
• Since a fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions
• To assist diagnosis, refer to 2 Wiring Diagrams and Connector Charts for the system wiring diagram and connector
charts.
Diagnostic Table for DTCs P0513, P0663, P1629, P1632, P1648, P1677, P1678, P1679
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for setting the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P0513, P1629, P1632, P0633, P1677, P1678 or P1679 fail
this ignition cycle? Go to Step 3
Refer to Additional
Information in this
Section
3 Using Tech 2, perform the BCM Link to ECM / PIM procedure. Refer
to 6E4 Powertrain Interface Module – GEN IV V8.
Has the linking procedure been performed correctly? Go to Step 7 Go to Step 4
4 Test the BCM system. Refer to 12J Body Control Module.
Has any fault been found and rectified? Go to Step 7 Go to Step 5
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–162
Page 6C4-2–162
Step Action Yes No
5 1 Test all ground circuits of the PIM for a high resistance or an
open circuit fault condition. Refer to 12P Wiring Diagrams for
information on electrical fault diagnosis.
2 Test the PIM ignition supply voltage circuit for a high resistance,
open circuit or short to ground fault condition. Refer to 12P
Wiring Diagrams for information on electrical fault diagnosis.
Has any fault been found and rectified? Go to Step 7 Go to Step 6
6 Replace the PIM. Refer to 6E4 Powertrain Interface Module – GEN IV
V8.
Has the repair been completed? Go to Step 7 —
7 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Do any of the immobiliser DTCs fail this ignition cycle? Go to Step 2 Go to Step 8
8 Using Tech 2, select the DTC display function.
Are there any DTCs displayed?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, clear all DTCs and check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–163
Page 6C4-2–163
6.26 DTC P0522, P0523
DTC Description
This diagnostic procedure covers the following DTCs:
• DTC P0522 – Engine Oil Pressure Sensor Low Voltage.
• DTC P0523 – Engine Oil Pressure Sensor High Voltage.
Circuit Description
The Engine Oil Pressure (EOP) Sensor is mounted in the top rear of the engine and measures changes in engine oil
pressure. The EOP Sensor has a 5.0 volt reference, a ground, and a signal circuit.
The EOP Sensor changes resistance based on engine oil pressure and is used to determine when the oil pressure is
outside a specified range.
When the oil pressure is below a predetermined value, the Engine Control Module (ECM) will determine this as low oil
pressure. The ECM will then send a serial data message to the instrument cluster to activate the Check Oil warning icon.
When the ECM senses a signal voltage outside the normal operating range of the sensor, DTC P0522 or DTC P0523 will
set.
Conditions for Running the DTCs
Run continuously when the engine is running.
Conditions for Setting the DTCs
Engine is running and system voltage is more than 11 volts.
• P0522 .Oil pressure sensor voltage less than 0.4 volts
• P0523 Oil pressure sensor voltage more than 4.89 volts
Conditions for Clearing the DTCs
The Engine Oil Pressure Sensor Circuit DTCs are Type C DTCs. Refer to 1.5 Diagnostic Trouble Codes for action taken
when Type C DTCs set and conditions for clearing Type C DTCs.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the Engine Oil
Pressure Sensor.
• An engine oil pressure fault could cause DTC P0522 or DTC P0523 to set.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Since a fault condition in a wiring connector may trigger DTCs, always test the sensor connectors related to this
diagnostic procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• Refer to 2 Wiring Diagrams and Connector Charts to aid in the diagnosis procedures.
Test Descriptions
The following numbers refer to the step numbers in the diagnostic chart:
3 An engine oil pressure fault could cause DTC P0522 or DTC P0523 to set. Always verify there are no engine oil
pressure concerns before continuing with this table.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–164
Page 6C4-2–164
Diagnostic Table for the Engine Oil Pressure Sensor Circuit DTCs
Step Action Value(s) Yes No
1 Has the Diagnostic System Check been performed?
– Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Observe the Freeze Frame / Failure Record for
this DTC.
2 Switch Off the ignition for 30 seconds.
3 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
4 Using Tech 2 select:
Engine / Diagnostic Trouble Codes / Read DTC
Information.
Does DTC P0522 or P0523 fail this ignition cycle? – Go to Step 3
Refer to Additional
Information in this
section
3 Perform an engine oil pressure check, refer to
6A4 Engine Mechanical – GEN IV V8.
Was any fault found and rectified? – Go to Step 12 Go to Step 4
4 1 Switch off the ignition.
2 Disconnect the EOP sensor electrical connector.
3 Turn on the ignition, with the engine not running.
4 Using a digital multimeter, measure the voltage
between the EOP sensor 5 volts reference circuit
and the ECM housing.
Is the voltage within the specified range? 4.8 – 5.2 V Go to Step 5 Go to Step 7
5 1 Switch Off the ignition.
2 Connect a 3 amp fused jumper wire between the
EOP sensor 5 volts reference circuit and signal
circuit.
3 Switch On the ignition with the engine not running.
4 Using Tech 2, observe the EOP sensor voltage
parameter.
Is the voltage within the specified value? 4.8 – 5.2 V Go to Step 6 Go to Step 9
6 1 Switch off the ignition.
2 Remove ECM Fuse 29 from the engine
compartment fuse and relay panel assembly.
3 Using a digital multimeter, measure the resistance
between the EOP sensor low reference circuit and
the ECM housing.
NOTE
Install ECM Fuse 29 to the engine
compartment fuse and relay panel assembly
after completing the test.
Is the resistance less than the specified value? 5 Ω Go to Step 10 Go to Step 9
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–165
Page 6C4-2–165
Step Action Value(s) Yes No
7 Test the EOP sensor 5 volts reference circuit for a high
resistance, open circuit, short to ground, or short to
voltage fault condition. Refer to 12P Wiring Diagrams
for information on electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 12 Go to Step 11
8 Test the EOP sensor signal circuit for a short to voltage,
short to ground, high resistance or an open circuit fault
condition. Refer to 12P Wiring Diagrams for information
on electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 12 Go to Step 10
9 Test the EOP sensor low reference circuit for an open
circuit or high resistance fault condition. Refer to 12P
Wiring Diagrams for information on electrical fault
diagnosis.
Was any fault found and rectified? – Go to Step 12 Go to Step 11
10 Replace the EOP sensor. Refer to 6A4 Engine
Mechanical – GEN IV V8.
Was the repair completed? – Go to Step 12 –
11 Replace the ECM. Refer to 6C4-3 Engine Management
GEN IV V8 – Service Operations.
Was the repair completed? – Go to Step 12 –
12 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
Does DTC P0522 or P0523 fail this ignition cycle? – Go to Step 2 Go to Step 13
13 Using Tech 2, select the DTC display function.
Are there any DTCs displayed? –
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–166
Page 6C4-2–166
6.27 DTC P0532, P0533
DTC Description
This diagnostic procedure supports the following DTCs:
• DTC P0532 – A/C Pressure Sensor Voltage Low
• DTC P0533 – A/C Pressure Sensor Voltage High
Circuit Description
The ECM supplies a positive 5 V reference voltage to the air-conditioning (A/C) refrigerant pressure sensor through
reference circuit and the ground through the low reference circuit.
The A/C pressure sensor provides signal voltage to the ECM through the signal circuit that is proportional to the A/C
refrigerant pressure. The ECM monitors the signal voltage of the A/C pressure sensor to determine the refrigerant
pressure.
• The A/C pressure sensor voltage increases as the refrigerant pressure increases.
• When the ECM detects the refrigerant pressure exceeds a predetermined value, the ECM activates the cooling
fans to reduce the refrigerant pressure.
• When the ECM detects the refrigerant pressure is too high or too low, the ECM disables the A/C clutch to protect
the A/C compressor from damage.
• An A/C refrigerant pressure sensor circuit DTC sets if the ECM detects the A/C pressure sensor signal is not within
the specified range for 3 seconds.
• To aid diagnosis, refer to 2 Wiring Diagrams and Connector Charts.
Conditions for Running the DTC
DTC P0532 and P0533 run continuously when the engine is running or when the A/C is switched on.
Conditions for Setting the DTC
DTC P0532
The A/C refrigerant pressure signal voltage is less than 0.2 V for longer than 3 seconds.
DTC P0533
The A/C refrigerant pressure signal voltage is greater than 4.9 V for longer than 3 seconds.
Conditions for Clearing the DTC
The A/C refrigerant pressure sensor circuit DTCs are Type C DTCs. Refer to 1.5 Diagnostic Trouble Codes for action
taken when Type C DTC sets and conditions for clearing Type C DTCs.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the A/C Refrigerant
Pressure Sensor operation.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• The A/C refrigerant pressure sensor circuit diagnostic table is developed with the assumption the A/C refrigerant
system is functioning correctly. Therefore, rectify any A/C refrigerant system fault conditions before proceeding with
this diagnostic procedure.
• An A/C refrigerant low-pressure fault condition may cause DTC P0532 to set.
• An A/C refrigerant high-pressure fault condition may cause DTC P0533 to set.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–167
Page 6C4-2–167
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• To assist diagnosis, refer to 2 Wiring Diagrams and Connector Charts, for the system wiring diagram and
connector charts.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
2 Determines if there is an A/C refrigerant system fault condition.
6 Measures the integrity of the A/C Refrigerant Pressure Sensor low reference circuit. Removal of the ECM Fuse 29
enables the ECM to power down completely prior to the test procedure.
DTC P0532 and P0533 Diagnostic Table
Step Action Value(s) Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 Test the A/C refrigerant system. Refer to 2B HVAC
Climate Control – Servicing and Diagnosis.
Was any fault found and rectified? Go to Step 12 Go to Step 3
3 1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for
running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P0532 or P0533 fail this ignition cycle? Go to Step 4
Refer to Additional
Information in this
section
4 1 Switch off the ignition.
2 Disconnect the A/C pressure sensor connector.
3 Switch on the ignition with the engine not running.
4 Using a digital multimeter, measure the voltage
between the A/C pressure sensor 5 V reference
circuit and the ECM housing.
Does the multimeter display between 4.8 – 5.2 V Go to Step 5 Go to Step 7
5 1 Connect a 3 A fused jumper wire between the A/C
pressure sensor 5 V reference circuit and signal
circuit.
2 Switch on the ignition with the engine not running.
3 Using Tech 2, observe the ECM A/C pressure
voltage parameter.
Does Tech 2 display between 4.8 – 5.2 V Go to Step 6 Go to Step 8
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–168
Page 6C4-2–168
Step Action Value(s) Yes No
6 1 Switch off the ignition.
2 Remove ECM Fuse 29 from the engine
compartment fuse and relay panel assembly.
3 Using a digital multimeter, measure the resistance
between the A/C refrigerant pressure low reference
circuit and the ECM housing.
NOTE
Install the ECM Fuse 29 to the engine
compartment fuse and relay panel assembly
after completing the test.
Does the multimeter display less than 5Ω Go to Step 10 Go to Step 9
7 Test the A/C pressure sensor 5 V reference circuit for a
high resistance, open circuit, short to ground, or short to
voltage fault condition. Refer to 12P Wiring Diagrams for
information on electrical fault diagnosis.
Was any fault found and rectified? Go to Step 12 Go to Step 11
8 Test the A/C pressure sensor signal circuit for a high
resistance, open circuit, short to ground, or short to
voltage fault condition. Refer to 12P Wiring Diagrams for
information on electrical fault diagnosis.
Was any fault found and rectified? Go to Step 12 Go to Step 11
9 Test the A/C pressure sensor low reference circuit for a
high resistance or open circuit condition. Refer to 12P
Wiring Diagrams for information on electrical fault
diagnosis.
Was any fault found and rectified? Go to Step 12 Go to Step 11
10 Replace the A/C pressure sensor. Refer to 6C4-3 Engine
Management –GEN IV V8 – Service Operations.
Was the repair completed? Go to Step 12 —
11 Replace the ECM. Refer to 6C4-3 Engine Management –
GEN IV V8 – Service Operations.
Was the repair completed? Go to Step 12 —
12 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC.
Does any of the A/C refrigerant pressure sensor circuit
DTCs fail this ignition cycle? Go to Step 2 Go to Step 13
13 Using Tech 2, select the DTC display function.
Are there any DTCs recorded? Go to the appropriate
DTC Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–169
Page 6C4-2–169
6.28 DTC P0562, P0563
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0562 – System Voltage Low Voltage
• DTC P0563 – System Voltage High Voltage
Circuit Description
Battery voltage is supplied continuously to the engine control module (ECM) through the continuous battery supply circuit
and the ground through the ground connection of the ECM housing to the engine.
Turning the ignition switch on activates the ignition control relay, which directs ignition positive voltage from the battery to
the ECM switched battery supply circuit which activates the ECM. The ECM then applies control voltage to the control
circuit of the Engine control relay to activate the Engine control relay. The Engine control relay supplies ignition voltage to
the various engine management system components.
The ECM monitors the battery voltage circuits to ensure the voltage available to the engine management system stays
within the specified range. Incorrect system voltage may cause incorrect engine management system operation or
component malfunction.
An ECM system voltage DTC sets if the ECM detects the voltage available to any of the ECM voltage supply circuit is
outside the specified range.
Conditions for Running the DTC
DTCs P0563 and P0563 runs continuously when the engine is running at speeds greater than 1500 rpm
Conditions for Setting the DTC
DTC P0562
The ECM detects the ECM system voltage is less than 11 V for 5 seconds.
DTC P0563
The ECM detects the ECM system voltage is greater than 16 V.
Conditions for Clearing the DTC
The ECM system voltage DTCs are Type C DTCs. Refer to 1.5 Diagnostic Trouble Codes for action taken when a Type
C DTC sets and conditions for clearing Type C DTCs.
Additional Information
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the ECM operation.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• To assist diagnosis, refer to 2 Wiring Diagrams and Connector Charts for the system wiring diagram and connector
charts.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–170
Page 6C4-2–170
DTC P0562 or P0563 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch off the ignition for 30 seconds.
2 Increase the engine speed to 1500 rpm or operate the vehicle
within the conditions for running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P0562 or P0563 fail this ignition cycle? Go to Step 3
Refer to Additional
Information in this
Section
3 Test the battery condition. Refer to 12A Battery.
Was any fault found and rectified? Go to Step 9 Go to Step 4
4 Test the charging system operation. Refer to 6D4-1 Charging System
– GEN IV V8.
Was any fault found and rectified? Go to Step 9 Go to Step 5
5 Test all the ECM fuses. Refer to 12O Relays, Fuses and Wiring
Harnesses.
Was any fault found and rectified? Go to Step 9 Go to Step 6
6 Check the ECM ground connections for corrosion, loose terminal or
incorrect position. Refer to 12P Wiring Diagrams for information on
electrical fault diagnosis.
Was any fault found and rectified? Go to Step 9 Go to Step 7
7 Test the following circuits for a high resistance or open circuit fault
condition.
• Continuous battery supply circuit,
• switched battery supply circuit,
• ignition 1 circuit, and
• ignition 2 circuit.
Refer to 12P Wiring Diagrams for information on electrical fault
diagnosis.
Was any fault found and rectified? Go to Step 9 Go to Step 8
8 Replace the ECM. Refer to 6C4-3 Engine Management – GEN IV V8
– Service Operations.
Was the repair completed? Go to Step 9 —
9 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Does any of the ECM system voltage DTCs fail this ignition cycle? Go to Step 2 Go to Step 10
10 Using Tech 2, select the DTC display function.
Are there any DTCs recorded?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–171
Page 6C4-2–171
6.29 DTC P0575
DTC Descriptor
This diagnostic procedure supports the following DTC
• DTC P0575 Cruise Control Switch Signal Circuit
Circuit Description
When a cruise control function switch is activated, the PIM detects a predetermined voltage signal. The PIM sends a
GMLAN serial data message to the engine control module (ECM) indicating the function that has been requested
Conditions for Running the DTC
This diagnostic runs continuously.
Conditions for Setting the DTC
The ECM receives an invalid cruise control switch status GMLAN serial data message from the PIM.
Conditions for Clearing the DTC
The CKP / CMP sensor correlation DTCs are Type C DTCs. Refer to 1.5 Diagnostic Trouble Codes for action taken
when Type C DTCs set and conditions for clearing Type C DTCs
Additional Information.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Since fault condition in a wiring connector may trigger the DTC, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to Section 12P
Wiring Diagrams for information on electrical fault diagnosis.
• To assist diagnosis 2 Wiring Diagrams and Connector Charts for the system wiring diagram and connector charts.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
This DTC may be stored as a history DTC without affecting the operation of the PIM. If stored only as a history DTC and
not retrieved as a current DTC, do not replace the PIM.
If this DTC is retrieved as both a current and history DTC, replace the PIM.
DTC P0575
Step Action Values Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch off the ignition for 30 seconds.
2 Start the engine.
3 Allow the engine to reach the normal operating
temperature.
4 Increase the engine speed to 2,000 rpm for 10
seconds.
5 Using Tech 2, select the DTC display function.
Does DTC P0575 fail this ignition cycle?
Go to Step 3
Refer to Additional
Information in this
Section
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–172
Page 6C4-2–172
Step Action Values Yes No
3 Replace the PIM, refer 6E4 Powertrain Interface
Module – GEN IV V8.
Was the repair completed?
Go to Step 4 Go to Step 2
4 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–173
Page 6C4-2–173
6.30 DTC P0601, P0602, P0603, P0604, P0606,
P0607, P062F, P1621, P1681, P2610
DTC Description
This diagnostic procedure supports the following DTCs:
• DTC P0601 – ECM Flash EEPROM Checksum Error
• DTC P0602 – ECM Programming Error
• DTC P0603 –ECM NVM Integrity
• DTC P0604 – ECM RAM Failure
• DTC P0606 – ECM Processor Fault
• DTC P0607 – No information available at time of publication
• DTC P062F– No information available at time of publication
Circuit Description
The engine control module (ECM) is the control centre of the engine management system. The programming and
calibration needed by the ECM to control the functionality of the engine management system are stored in the ECM read
only memory (ROM).
An ECM internal circuit, programming or memory fault DTC sets if there is an internal microprocessor integrity fault
condition with the ECM or if the ECM is not programmed.
To aid diagnosis, refer to Section 12P Wiring Diagrams for the system wiring diagram and connector charts.
Conditions for Running the DTC
DTC P0601
Runs once when the checksum calculation at power down is completed in the last ignition cycle.
DTC P0602,P0603 and P0606
Runs continuously when the ignition is switched on with the engine not running.
DTC P0604
Runs once when the read / write test at power-down is completed in the last ignition cycle.
DTC P0607
No information available at time of publication.
DTC P062F
No information available at time of publication.
Conditions for Setting the DTC
DTC P0601
The ECM detects an incorrect ROM checksum.
DTC P0602
The ECM programming is incomplete.
DTC P0603
Indicates the ECM has had a long term memory reset.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–174
Page 6C4-2–174
DTC P0604
The ECM detects an error in the RAM.
DTC P0606
There is an internal ECM circuit fault condition.
DTC P0607
No information available at time of publication.
DTC P062F
No information available at time of publication.
Conditions for Clearing the DTC
The ECM Internal Circuit, Programming or Memory Fault DTCs are Type A DTCs. Refer to 1.5 Diagnostic Trouble Codes
for action taken when a Type A DTC sets and conditions for clearing Type A DTCs.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the ECM operation.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
DTC P0601, P0602, P0603, P0604, P0606, P0607 and P062F Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P0601, P0602.P0603, P0604, P0606, P0607 or P062F fail
this ignition cycle? Go to Step 3
Refer to Additional
Information in this
Section
3 Test all ECM fuses and ground connections. Refer to 12O Relays,
Fuses and Wiring Harnesses.
Was any fault found and rectified? Go to Step 6 Go to Step 4
4 Attempt to program the ECM. Refer to 0C Tech 2.
Was the programming successful? Go to Step 6 Go to Step 5
5 Replace the ECM. Refer to 6C4-3 Engine Management – GEN IV V8
– Service Operations.
Was the repair completed? Go to Step 6 —
6 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Does any of the ECM internal circuit, programming or memory fault
DTCs fail this ignition cycle? Go to Step 2 Go to Step 7
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–175
Page 6C4-2–175
Step Action Yes No
7 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–176
Page 6C4-2–176
6.31 DTC P0608
DTC Description
This diagnostic procedure covers DTC P0608 – Vehicle Speed Output Circuit.
Circuit Description
The Engine Control Module (ECM) creates a Vehicle Speed Output signal by rapidly grounding the circuit via an internal
switch called a driver. The driver operates at the same rate as the VSS signal input. The driver has a fault line which the
ECM monitors. If the fault line senses a voltage other than what is expected, the fault line status changes causing a
Vehicle Speed Output Circuit DTC to set.
Conditions for Running the DTC
• The engine speed is greater than 600 RPM.
• The ignition voltage is between 6.0 and 16.0 volts.
Conditions for Setting the DTC
• The ECM detects that the commanded state of the driver and the actual state of the circuit do not match.
• This condition must be present for at least 10 seconds.
Conditions for Clearing DTCs
The Vehicle Speed Output Circuit DTC is a Type C DTC. Refer to 1.5 Type C, Diagnostic Trouble Codes for action taken
when a Type C DTC sets and conditions for clearing a Type C DTC.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the ECM operation.
• For diagnosis on any further concerns with the instrument system, refer to Section 12C Instrumentation.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• Refer to 2 Wiring Diagrams and Connector Charts to aid in the diagnosis procedures.
Test Descriptions
The following numbers refer to the step numbers in the diagnostic chart:
7 If the instrument cluster does not provide a voltage to the vehicle speed output circuit, there is a fault with the
instrument system.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–177
Page 6C4-2–177
Diagnostic Table for the Vehicle Speed Output Circuit DTC
Step Action Value(s) Yes No
1 Has the diagnostic system check been performed?
– Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Using Tech 2, observe the Freeze Frame / Failure
Records for this DTC.
2 Switch off the ignition for 30 seconds.
3 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
4 Using Tech 2 select:
Engine / Diagnostic Trouble Codes / Read DTC
Information.
Does DTC P0608 fail this ignition cycle? – Go to Step 3
Refer to Additional
Information in this
section
3 1 Switch on the ignition.
2 Connect a digital multimeter between the speed
signal circuit and a known ground.
Does the multimeter indicate the specified value? B+ Go to Step 4 Go to Step 5
4
To avoid damage to the drive axles,
support the lower control arms in the
normal horizontal position. Do not run
the vehicle in gear with the wheels
hanging down at full travel.
1 Switch off the ignition.
2 Raise the vehicle and support the drive axles with
safety stands. Refer to 0A General Information for
the location of jacking and support points.
3 Start the engine.
4 Disable the ABS/TCS system.
5 Select a forward gear.
6 Connect a digital multimeter between the speed
signal circuit and a known ground.
Is the reading greater than the specified value? 0.5 V AC
Refer to Additional
Information in this
section Go to Step 6
5 1 Switch off the ignition.
2 Disconnect the ECM.
3 Switch on the ignition with the engine not running.
4 Connect a digital multimeter between the speed
signal circuit and a known ground.
Does the multimeter indicate the specified value? B+ Go to Step 9 Go to Step 7
6 Test the speed signal output circuit for a short to voltage
fault condition. Refer to 12P Wiring Diagrams for
information on electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 10 Go to Step 8
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–178
Page 6C4-2–178
Step Action Value(s) Yes No
7 Test the speed signal output circuit for a high
resistance, open circuit, or short to ground fault
condition. Refer to 12P Wiring Diagrams for information
on electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 10 Refer to 12C
Instrumentation
8 Test the speed signal output circuit for a high
resistance, open circuit, or short to ground fault
condition. Refer to 12P Wiring Diagrams for information
on electrical fault diagnosis.
Was any fault found and rectified? – Go to Step 10 Go to Step 9
9 Replace the ECM. Refer to 6C3-3 Engine Management
GEN IV V8 – Service Operations.
Was the repair completed? – Go to Step 10 –
10 1 Using Tech 2, clear the DTCs.
2 Switch Off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
Does DTC P0608 fail this ignition cycle? – Go to Step 2 Go to Step 10
11 Using Tech 2, select the DTC display function.
Are there any DTCs displayed? –
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–179
Page 6C4-2–179
6.32 DTC P060D, P1680, P2120, P2122, P2123,
P2125, P2127, P2128, P2138
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P060D - Internal Control Module Accelerator Pedal Position Performance
• DTC P1680 - Accelerator Pedal Position Sensor Circuit Malfunction
• DTC P2120 - Accelerator Pedal Position (APP) Sensor 1 Circuit
• DTC P2122 – Accelerator Pedal Position Sensor 1 Voltage Low
• DTC P2123 – Accelerator Pedal Position Sensor 1 Voltage High
• DTC P2125 - Accelerator Pedal Position (APP) Sensor 2 Circuit
• DTC P2127 – Accelerator Pedal Position Sensor 2 Voltage Low
• DTC P2128 – Accelerator Pedal Position Sensor 2 Voltage High
• DTC P2138 – Accelerator Pedal Position Sensor 1 – 2 Correlation
Circuit Description
The ECM applies a separate 5 V reference circuit and low reference circuit to the accelerator pedal position (APP) sensor
1 and sensor 2. The APP sensors produce a signal voltage that represents the accelerator pedal position.
• The APP sensor 1 signal voltage increases from 1 V at rest position to greater than 4 V when the accelerator pedal
is fully depressed.
• The APP sensor 2 signal voltage increases from 0.5 V at rest position to greater than 2 V when the accelerator
pedal is fully depressed.
The ECM monitors and evaluates the APP sensors signal voltage along with other sensor inputs to determine the desired
throttle opening. An APP sensor circuit DTC sets if the signal voltage of the APP sensor is outside the predetermined
range.
Conditions for Running the DTC
DTC P060D
• Engine running or cranking.
• System voltage more than 5.2volts.
• No ECM processor codes present.
DTC P1680
No information available at time of publication
DTC P2120, P2122, P2123, P2125, P2127, P2128 and P2138
Run continuously once the following conditions are met:
• The ignition is switched on.
• The ignition voltage is greater than 7 V.
• No ECM processor codes present.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–180
Page 6C4-2–180
Conditions for Setting the DTC
DTC P060D
The ECM detects APP sensor 2 is more than 2.05 volts
DTC P1680
No information available at time of publication
DTC P2120
The EMC determines the APP sensor 1 signal voltage is less than 0.36volts or more than 2.6 volts
DTC P2122
The ECM determines the APP sensor 1 signal voltage is less than 0.84 V.
DTC P2123
The ECM determines the APP sensor 1 signal voltage is greater than 4.82 V.
DTC P2125
The EMC determines the APP sensor 2 signal voltage is less than 0.36volts or more than 2.6 volts
DTC P2127
The ECM determines the APP sensor 2 signal voltage is less than 0.66 V.
DTC P2128
The ECM determines the APP sensor 2 signal voltage is greater than 4.82 V.
DTC P2138
The ECM detects the difference between the APP sensor 1 and sensor 2 signal voltage is greater than the
predetermined value.
Conditions for Clearing DTC
The APP sensor circuit DTCs are Type ‘A’ DTCs. Refer to 1.5 Diagnostic Trouble Codes for action taken when a Type
‘A’ DTC sets and conditions for clearing Type ‘A’ DTCs.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the APP sensor
operation.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• To assist diagnosis, refer to 2 Wiring Diagrams and Connector Charts for the system wiring diagram and connector
charts.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
2 Tests the APP sensor internal circuits throughout its range of motion. If the DTC fails while performing this test,
there is an internal fault condition in the APP sensor internal circuitry.
5 Measures the integrity of the TP sensor low reference circuit. Removal of the ECM F use 29 enables the ECM to
power down completely prior to the test procedure.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–181
Page 6C4-2–181
DTC P060D, P2120, P2122, P2123, P2125, P2127, P2128, P2138 Diagnostic Table
Step Action Values Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch off the ignition for 30 seconds.
2 Start the engine.
3 Quickly depress the accelerator pedal to wide-open
throttle then release pedal. Repeat this procedure
several times or operate the vehicle within the
conditions for running the DTC.
4 Using Tech 2, select the DTC display function.
Does DTC P2122, P2123, P2127, P2128 or P2138 fail
this ignition cycle? Go to Step 3
Refer to Additional
Information in this
Section
3 1 Disconnect the APP sensor wiring connector.
2 Switch on the ignition with the engine not running.
3 Using a digital multimeter, measure the voltage
between the 5 V reference circuit of the appropriate
APP sensor and the ECM housing.
Does the multimeter display 4.8 – 5.2 V? Go to Step 4 Go to Step 6
4 1 Connect a 3 A fused jumper wire between the 5 V
reference circuit and the signal circuit of the
appropriate APP sensor.
2 Switch on the ignition with the engine not running.
3 Using Tech 2, observe the voltage parameter
appropriate APP sensor.
Does Tech 2 display 4.8 – 5.2 V? Go to Step 5 Go to Step 7
5 1 Switch off the ignition.
2 Remove ECM Fuse 29 from the engine
compartment fuse and relay panel assembly.
3 Using a DMM, measure the resistance between the
appropriate TP sensor low reference circuit and the
ECM housing.
NOTE
Install the ECM Fuse 29 to the engine
compartment fuse and relay panel assembly
after completing this test.
Does the multimeter display 5 Ω or less? Go to Step 9 Go to Step 8
6 Test the 5 V reference circuit of the appropriate APP
sensor for a high resistance, open circuit, short to ground
or short to voltage fault condition. Refer to 12P Wiring
Diagrams for information on electrical fault diagnosis.
Was any fault found and rectified? Go to Step 11 Go to Step 10
7 Test the signal circuit of the appropriate APP sensor for a
high resistance, open circuit, short to ground or short to
voltage fault condition. Refer to 12P Wiring Diagrams for
information on electrical fault diagnosis.
Was any fault found and rectified? Go to Step 11 Go to Step 10
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–182
Page 6C4-2–182
Step Action Values Yes No
8 Test the low reference circuit of the appropriate APP
sensor for a high resistance or an open circuit fault
condition. Refer to 12P Wiring Diagrams for information
on electrical fault diagnosis.
Was any fault found and rectified? Go to Step 11 Go to Step 10
9 Replace the accelerator pedal assembly. Refer to 6C4-3
Engine Management – GEN IV V8 – Service Operations.
Was the repair completed? Go to Step 11 —
10 Replace the ECM. Refer to 6C4-3 Engine Management –
GEN IV V8 – Service Operations.
Was the repair completed? Go to Step 11 —
11 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC.
Do any of the APP Sensor Circuit DTCs fail this ignition
cycle? Go to Step 2 Go to Step 12
12 Using Tech 2, select the DTC display function.
Are the any DTCs recorded?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–183
Page 6C4-2–183
6.33 DTC P0621, P0622
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0621 Generator L-Terminal Circuit
• DTC P0622 Generator F-Terminal Circuit
Circuit Description
The Engine Control Module (ECM) uses the generator field duty cycle signal circuit to monitor the duty cycle of the
generator. The generator field duty cycle signal circuit connects to the high side of the field winding in the generator. A
pulse width modulated (PWM) high side driver in the voltage regulator turns the field winding ON and OFF. The ECM
uses the PWM signal input to determine the generator load on the engine. This allows the ECM to adjust the idle speed
to compensate for high electrical loads.
The ECM monitors the state of the generator field duty cycle signal circuit. When the key is in the RUN position and the
engine is OFF, the ECM should detect a duty cycle near 0 percent. However, when the engine is running, the duty cycle
should be between 5 percent and 100 percent. The ECM monitors the PWM signal using a key ON test and a RUN test.
During the tests, if the ECM detects an out of range PWM signal, DTC P0622 will set. When the DTC sets, the ECM will
send a class 2 serial data message to the instrument panel cluster (IPC) to illuminate the charge indicator.
Conditions for Running the DTC
DTC P0621
• Key ON Test.
• No generator, crankshaft position (CKP) sensors, or camshaft position (CMP) sensor DTCs are set.
• The key is in the RUN position.
• The engine is not running.
• Run Test.
• No generator, CKP sensors, or CMP sensor DTCs are set.
• The engine is less than 3000 RPM.
DTC P1622
• Key ON Test.
• No generator, crankshaft position (CKP) sensors, or camshaft position (CMP) sensor DTCs are set.
• The key is in the RUN position.
• The engine is not running.
• Run Test.
• No generator, CKP sensors, or CMP sensor DTCs are set.
• The engine is less than 3000 RPM.
Conditions for Setting the DTC
DTC P0621
• During the ignition ON test, the ECM detects a PWM signal is out of range.
• During the RUN test, the ECM detects a PWM signal less then 5 percent for more than 6 seconds.
DTC P1622
• During the ignition ON test, the ECM detects a PWM signal is out of range.
• During the RUN test, the ECM detects a PWM signal less then 5 percent for more than 6 seconds.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–184
Page 6C4-2–184
Conditions for Clearing DTC
The generator terminal circuit DTCs are Type ‘C” DTCs. Refer to 1.5 Diagnostic Trouble Codes for action taken when a
Type ‘C’ DTC sets and conditions for clearing Type ‘C’ DTCs.
Additional Information
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• To assist diagnosis, refer to 2 Wiring Diagrams and Connector Charts for the system wiring diagram and connector
charts.
DTC P0621 AND P0622 Diagnostic Table
Step Action Values Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1. Install a scan tool.
2. Start the engine.
3. With a scan tool, observe the GEN - F Terminal
parameter in the engine data list.
Does the scan tool indicate that the GEN - F Terminal
parameter is within the specified range? 5-95%
Refer to Additional
Information in this
Section Go to Step 3
3 1. Turn ON the ignition, leaving the engine OFF.
2. Connect a test lamp to battery positive voltage and
repeatedly probe the generator field duty cycle
signal circuit or F- Terminal in the harness
connector while monitoring the Generator F-
Terminal Signal on the scan tool.
Is the Generator F-Terminal Signal display affected?
--
Go to Step 5 Go to Step 4
4 Test the generator field duty cycle signal circuit for a
short or open. Refer to 12P Wiring Diagrams for
information on electrical fault diagnosis.
Did you find and correct the condition?
--
Go to Step 8 Go to Step 6
5 Inspect for poor connections at the harness connector of
the generator. Refer to 12P Wiring Diagrams for
information on electrical fault diagnosis.
Did you find and correct the condition?
--
Go to Step 8
Go to 6D4-1
Charging System –
GEN IV V8
6 Inspect for poor connections at the harness connector of
the Engine Control Module ECM. Refer to 12P Wiring
Diagrams for information on electrical fault diagnosis.
Did you find and correct the condition?
--
Go to Step 8 Go to Step 7
7 Replace the ECM. Refer to 6C4-3 Engine Management -
GEN IV V8 – Service Operations.
Was the repair completed? -- Go to Step 8 –
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–185
Page 6C4-2–185
Step Action Values Yes No
8 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC.
Do any of the generator terminal circuit DTCs fail this
ignition cycle?
--
Go to Step 2 Go to Step 9
9 Using Tech 2, select the DTC display function.
Are the any DTCs recorded?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–186
Page 6C4-2–186
6.34 DTC P0641 P0651
DTC Description
This diagnostic procedure supports DTC P0641 – 5 Volt Reference Circuit 1 Malfunction.
This diagnostic procedure supports DTC P0651 – 5 Volt Reference Circuit 2 Malfunction.
Circuit Description
These 5-volt reference circuits are independent of each other outside the ECM, but are bussed together inside the ECM.
Therefore a circuit condition on one sensor 5-volt reference circuit may affect the other sensor 5-volt reference circuits.
The ECM monitors the voltage on the 5-volt reference circuit. If the ECM detects that the voltage is out of tolerance,
DTC P0641 or P0651 sets.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
• The ECM detects a voltage out of tolerance condition of the 5-volt reference circuit.
• The above condition is present for longer than 10 seconds.
Conditions for Clearing the DTC
The 5 Volt Reference Circuit 1 Malfunction DTC is a Type B DTC. Refer to1.5 Diagnostic Trouble Codes for action taken
when Type B DTCs set and conditions for clearing Type B DTCs.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the MAP and EOP
sensor operation.
• Since a fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to Section 12P
Wiring Diagrams for information on electrical fault diagnosis.
• Refer to 2 Wiring Diagrams and Connector Charts to aid in diagnosis.
• For intermittent fault conditions, refer to 4.2 Intermittent Fault Conditions.
DTC P0641 Diagnostic Table
Step Action value Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Using Tech 2, observe the Freeze Frame / Failure
Records for this DTC.
2 Switch off the ignition for 30 seconds.
3 Operate the vehicle within the conditions for
running the DTC or within the conditions in the
Freeze Frame / Failure Records.
4 Using Tech 2 select:
Engine / Diagnostic Trouble Codes / Read DTC
Information.
Does DTC P0641 or P0651 fail this ignition cycle? Go to Step 3
Refer to Additional
Information in this
Section
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–187
Page 6C4-2–187
Step Action value Yes No
3 1 Turn the ignition off.
2 measure the voltage on 5V signal wire
Does the multimeter display between 4.8 – 5.2 V?
Refer to Additional
Information in this
Section Go to Step 4
4 1 Turn the ignition off.
2 Measure the voltage on 5V signal wire
3 Disconnect sensors on 5V reference wire
Does the multimeter display between 4.8 – 5.2 V? Go to Step 8 Go to Step 5
5 Was the voltage displayed in Step 3 greater than 5.2 V? Go to Step 8 Go to Step 6
6 Was the voltage displayed in Step 3 less than
4.8V? Go to Step 7
Refer to Additional
Information in this
Section
7 1 Turn the ignition off.
2 Disconnect the ECM connector.
3 Using a multimeter, test 5V reference wire for a
short to ground or short to other circuits in the
harness.
Was a fault found and rectified? Go to Step 11 Go to Step 10
8 1 Turn the ignition off.
2 Disconnect the ECM connector.
3 Turn the ignition on with the engine not running.
4 Using a multimeter, test 5V reference circuits for a
short to voltage.
Was a fault found and rectified? Go to Step 11 Go to Step 10
9 Replace the faulty sensor. Refer to 6C4-3 Engine
Management – GEN IV V8 – Service Operations.
Was the repair completed? Go to Step 11 —
10 Replace the ECM. Refer to 6C4-3 Engine Management –
GEN IV V8 – Service Operations.
Was the repair completed? Go to Step 11 —
11 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC.
Does any of the Heated O2 Sensor heater control circuit
DTCs fail this ignition cycle? Go to Step 2 Go to Step 12
12 Using Tech 2, select the DTC display function.
Are there any recorded DTCs?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–188
Page 6C4-2–188
6.35 DTC P0645
DTC Description
This diagnostic procedure covers
DTC P0645 – A/C Relay Circuit Malfunction.
Circuit Description
The engine control relay applies battery voltage to the coil circuit of the Air-conditioning (A/C) clutch relay through the
ignition circuit. Using a device called a Driver, the ECM grounds control circuit of the A/C clutch relay to activate the A/C
clutch and operate the A/C compressor. Refer to Section 2A HVAC Climate Control (Manual A/C) – Description and
Operation for details of the A/C compressor operation.
The Driver has a feedback circuit that is pulled-up to a voltage. The ECM monitors the Driver feedback circuit to
determine if the control circuit is open, shorted to ground or shorted to a positive voltage.
An A/C clutch relay control circuit DTC sets if the ECM detects a fault condition in the A/C clutch relay control circuit.
Conditions for Running the DTC
The ignition is on and the A/C is switched on.
Conditions for Setting the DTC
The ECM detects that the commanded state of the driver and the actual state of the circuit do not match.
Conditions for Clearing the DTC
The Vehicle Speed Output Circuit DTC is a Type C DTC. Refer to 1.5 Diagnostic Trouble Codes for action taken when a
Type C DTC sets and conditions for clearing a Type C DTC.
Additional Information
• Refer to Section 2A HVAC Climate Control – Description and Operation for details of the A/C system operation.
• For diagnosis on any further concerns with the A/C system, refer to Section 2A HVAC Climate Control – Description
and Operation.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• Refer to 2 Wiring Diagrams and Connector Charts to aid in the diagnosis procedures.
Diagnostic Table for the A/C Clutch Relay Control Circuit DTC
Step Action Yes No
1 Was the Main Diagnostic System Check performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–189
Page 6C4-2–189
Step Action Yes No
2 1 Using Tech 2, observe the Freeze Frame / Failure Records for
this DTC.
2 Switch off the ignition for 30 seconds.
3 Operate the vehicle within the conditions for running the DTC or
within the conditions in the Freeze Frame / Failure Records.
4 Using Tech 2 select:
Engine / Diagnostic Trouble Codes / Read DTC Information.
Does DTC P0645 fail this ignition cycle? Go to Step 3
Refer to Additional
Information in this
section
3 1 Remove the A/C clutch relay. Refer to 12O Fuses, Relays and
Wiring Harnesses.
2 Connect a test lamp between the ignition circuit of the A/C clutch
relay coil and the ECM housing.
3 Switch on the ignition with the engine not running.
Does the test lamp illuminate? Go to Step 4 Go to Step 5
4 1 Connect a test lamp between the control circuit of the A/C clutch
relay and B+.
2 Switch on the ignition with the engine not running.
3 Using Tech 2, command the A/C clutch relay On and then Off.
Does the test lamp turn on and off when the A/C clutch relay is
commanded On and Off? Go to Step 7 Go to Step 6
5 Repair the high resistance or open circuit fault condition in the ignition
voltage circuit of the A/C clutch relay. Refer to 12P Wiring Diagrams
for information on electrical wiring repair procedures.
Was the repair completed? Go to Step 9 –
6 Test the control circuit of the A/C clutch relay for a high resistance,
open circuit, short to ground or short to voltage fault condition. Refer
to 12P Wiring Diagrams for information on electrical fault diagnosis.
Was any fault found and rectified? Go to Step 9 Go to Step 8
7 Replace the A/C clutch relay. Refer to 12O Fuses, Relays and Wiring
Harnesses.
Was the repair completed? Go to Step 9 –
8 Replace the ECM. Refer to 6C4-3 Engine Management GEN IV V8 –
Service Operations.
Was the repair completed? Go to Step 9 –
9 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Do any of the A/C clutch relay control circuit DTCs fail this ignition
cycle? Go to Step 2 Go to Step 10
10 Using Tech 2, select the DTC display function.
Are there any DTCs displayed?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–190
Page 6C4-2–190
6.36 DTC P0685, P0689, P0690
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0685 – Engine Control Ignition Relay Circuit Malfunction
• DTC P0686 – Engine Control Ignition Relay Circuit Low Voltage
• DTC P0687 – Engine Control Ignition Relay Circuit High Voltage
Circuit Description
The supply voltage circuit of the engine control relay is directly connected to battery voltage. When the ignition switch is
turned on, the ECM grounds the relay control circuit to provide ignition voltage to various sensors and components that
controls the engine operation.
The ECM monitors the control circuit of the engine control relay for conditions that are incorrect for the commanded state.
An engine control relay circuit DTC sets if the ECM detects a fault condition in this circuit.
Conditions for Running the DTC
DTCs P0685, P0686 and P0687 run continuously once the following conditions are met:
• The ignition is switched on.
• The ignition voltage is 10.0 – 16.0 V.
Conditions for Setting the DTC
The ECM detects a condition that is incorrect for the engine control relay commanded state.
Conditions for Clearing the DTC
The engine control relay control circuit DTCs are Type C DTCs. Refer to 1.5 Diagnostic T r ouble Codes for action taken
when Type C DTCs set and conditions for clearing Type C DTCs.
Additional Information
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• To assist diagnosis, refer to Section 12P Wiring Diagrams for the system wiring diagram and connector charts.
Test Description
The following number refers to the step number in the diagnostic table:
4 Removal of the ECM Fuse 29 enables the ECM to power down completely prior to the test procedure.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–191
Page 6C4-2–191
DTC P0685, P0686 or P0690 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch off the ignition for 30 seconds.
2 Turn the ignition switch to the Start position or operate the
vehicle within the conditions for running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P0685, P0686 and P0687 fail this ignition cycle? Go to Step 3
Refer to Additional
Information in this
Section
3 1 Remove the engine control relay. Refer to 12O Fuses, Relays
and Wiring Harnesses.
2 Connect a test lamp between the battery voltage circuit of the
engine control relay and a good ground.
Does the test lamp illuminate? Go to Step 4 Go to Step 5
4 1 Switch off the ignition.
2 Remove and reinstall the ECM fuse 29 from the engine
compartment fuse and relay panel assembly.
3 Connect a test lamp between the control circuit and the battery
voltage circuit of the engine control relay.
4 Switch on the ignition.
Does the test lamp switches from off to on when the ignition switch is
turned form off to on? Go to Step 7 Go to Step 6
5 Repair the high resistance or open circuit fault condition in the battery
voltage circuit of the engine control relay. Refer to 12P Wiring
Diagrams for information on electrical wiring repair procedures.
Was the repair completed? Go to Step 9 —
6 Test the control circuit of the engine control relay for a high resistance,
open circuit, short to ground or a short to voltage fault condition. Refer
to 12P Wiring Diagrams for information on electrical fault diagnosis.
Was any fault found and rectified? Go to Step 9 Go to Step 8
7 Replace the engine control relay. Refer to 12O Fuses, Relays and
Wiring Harnesses.
Was the repair completed? Go to Step 9 —
8 Replace the ECM. Refer to 6C4-3 Engine Management –GEN IV V8 –
Service Operations.
Was the repair completed? Go to Step 9 —
9 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Does the engine control relay control circuit DTCs fail this ignition
cycle? Go to Step 2 Go to Step 10
10 Using Tech 2, select the DTC display function.
Are there any DTCs displayed?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–192
Page 6C4-2–192
6.37 DTC P0700
DTC Descriptor
This diagnostic procedure supports DTC P0700 – Malfunction Indicator Lamp (MIL) Request from T ransmission Control
Module (TCM).
Circuit Description
The Engine Control Module (ECM) communicates directly with the Transmission Control Module (TCM) and other control
modules connected to the GMLAN serial data communication circuit through the GMLAN protocol.
DTC P0700 – Malfunction Indicator Request from the TCM sets if the following condition exists:
• The TCM detects an emission related fault condition and sets a TCM DTC that represent the fault condition.
• The ECM receives a serial data signal from the TCM requesting the illumination of the malfunction indicator.
Conditions for Running the DTC
DTC P0700 runs continuously when the ignition is switched on.
Conditions for Setting the DTC
The ECM receives a serial data signal from the TCM requesting the illumination of the malfunction indicator.
Conditions for Clearing the DTC
DTC P0700 – Malfunction Indicator Request from TCM is a T ype A DTCs. Refer to 1.5 Diagnostic T r ouble Codes for
action taken when a Type A DTC sets and conditions for clearing Type A DTCs.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the ECM operation.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• To assist diagnosis, refer to 2 Wiring Diagrams and Connector Charts for the system wiring diagram and connector
charts.
DTC P0700 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P0700 fail this ignition cycle? Go to Step 3
Refer to Additional
Information in this
Section
3 Are other ECM or TCM DTCs also set?
Refer to appropriate
DTC table
Refer to
7D2 Automatic
Transmission –
4L65E – Electrical
Diagnosis
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–193
Page 6C4-2–193
6.38 DTC P0719, P0724
DTC Descriptor
This diagnostic procedure supports the following DTC
• DTC P0719 Brake Switch Circuit Low Voltage
• DTC P0724 Brake Switch Circuit High Voltage
Circuit Description
The brake switch indicates brake pedal status to the Engine Control Module (ECM). The brake switch is a normally-
closed switch that supplies battery voltage on the torque converter clutch (TCC) brake switch signal circuit to the ECM.
Applying the brake pedal opens the switch, interrupting voltage to the ECM. When the brake pedal is released, the ECM
receives a constant voltage signal. If the ECM receives a zero voltage signal at the brake switch input, and the TCC is
engaged, the ECM de-energizes the TCC solenoid valve. The ECM disregards the brake switch input for TCC scheduling
if there is a brake switch circuit fault.
Conditions for Running the DTC
DTC P0719
• No VSS DTCs P0502 or P0503.
• The ignition is ON.
• DTC P0719 has not passed
DTC P0724
• No VSS DTCs P0502 or P0503.
• The ignition is ON.
• DTC P0719 has not passed
Conditions for Setting the DTCs
• The ECM detects a closed brake switch circuit, 12-volts, without changing for 2 seconds and the following
events occur eight times:
• The vehicle speed is greater than 32 km/h for 6 seconds;
• The vehicle speed is between 8-32 km/h for 4 seconds;
• The vehicle speed is less than 8 km/h
Conditions for Clearing the DTC
The CKP / CMP sensor correlation DTCs are Type C DTCs. Refer to 1.5 Diagnostic Trouble Codes for action taken
when Type C DTCs set and conditions for clearing Type C DTCs
Additional Information
• Inspect the brake switch for proper mounting and operation.
• Inspect for ABS DTCs. A faulty ABS condition may contribute to setting DTC P0719 or P0724.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Since fault condition in a wiring connector may trigger the DTC, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to Section 12P
Wiring Diagrams for information on electrical fault diagnosis.
• To assist diagnosis, 2 Wiring Diagrams and Connector Charts for the system wiring diagram and connector charts.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–194
Page 6C4-2–194
Test Description
The following numbers refer to the step numbers in the diagnostic table:
3 This step isolates the brake switch as a source for setting the DTC.
DTC P0016
Step Action Values Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch off the ignition for 30 seconds.
2 Start the engine.
3 Allow the engine to reach the normal operating
temperature.
4 Using Tech 2, select the DTC display function.
Does DTC P0719 or P0724 fail this ignition cycle?
Go to Step 3
Refer to Additional
information in this
Section
3 1 Install Tech 2
2 Turn on the ignition with the engine off
3 Select the TCC Brake Switch on Tech 2
4 Disconnect the brake switch
5 Connect a test lamp from power wire of the
connector to ground
Does the test lamp illuminate?
Go to Step 4 Go to Step 5
4 Connect a fused jumper wire between the power wire at
connector and the TCC brake switch wire
Did the TCC brake switch status on Tech 2 change from
opened to closed
Go to Step 7 Go to Step 8
5 Check brake switch power wire for high resistance open
circuit short to ground or short to voltage condition .
Refer to 12P Wiring Diagrams for information on
electrical fault diagnosis.
Was any fault found and rectified?
Go to Step 9 Go to Step 6
6 Check brake switch signal wire for high resistance open
circuit short to ground or short to voltage condition. Refer
to 12P Wiring Diagrams for information on electrical fault
diagnosis.
Was any fault found and rectified?
Go to Step 9 Go to Step 8
7 Replace the stop lamp switch, refer to 12B Lighting
Systems.
Did you complete the replacement? -- Go to Step 9 --
8 Replace the ECM. Refer to 6C4-3 Engine Management –
GEN IV V8 – Service Operations.
Was the repair completed? -- Go to Step 9 --
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–195
Page 6C4-2–195
Step Action Values Yes No
9 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC.
Does any of the crankshaft / camshaft position
correlation DTCs fail this ignition cycle?
Go to Step 2 Go to Step 10
10 Using Tech 2, select the DTC display function.
Are there any DTCs displayed?
Go to the appropriate
DTC Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–196
Page 6C4-2–196
6.39 DTC P0801
DTC Description
This diagnostic procedure covers
DTC P0801 – Reverse Inhibit Solenoid Circuit Fault.
Circuit Description
The Engine Control relay supplies an ignition voltage through fuse F32 to the reverse inhibit solenoid. The Engine Control
Module (ECM) controls the solenoid by grounding the control circuit via an internal switch called a driver. The driver has a
fault line which the ECM monitors. When the ECM commands the solenoid on, the voltage of the control circuit should be
low (near 0 volts), and high (near battery voltage) when the ECM commands the solenoid off.
If the internal fault detection circuit senses a voltage other than what is expected, the fault line status changes causing
DTC P0801 to set.
Conditions for Running the DTC
Information not available at time of publication.
Conditions for Setting the DTC
The ECM detects the commanded state of the circuit and the actual state of the circuit do not match.
Conditions for Clearing DTCs
The Reverse Inhibit Solenoid Control Circuit DTC is a Type C DTC. Refer to 1.5 Diagnostic Trouble Codes for action
taken when a Type C DTC sets and conditions for clearing a Type C DTC.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the reverse inhibit
solenoid operation.
• For diagnosis on any further concerns with the manual transmission, refer to Section 7B4 Manual Transmission –
GEN IV V8.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• Refer to 2 Wiring Diagrams and Connector Charts to aid in the diagnosis procedures.
Diagnostic Table for the Reverse Inhibit Solenoid Control Circuit DTC
Step Action Yes No
1 Was the Main Diagnostic Table performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Using Tech 2, observe the Freeze Frame / Failure Records for
this DTC.
2 Switch off the ignition for 30 seconds.
3 Operate the vehicle within the conditions for running the DTC or
within the conditions in the Freeze Frame / Failure Records.
4 Using Tech 2 select:
Engine / Diagnostic Trouble Codes / Read DTC Information.
Does DTC P0801 fail this ignition cycle? Go to Step 3
Refer to Additional
Information in this
section
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–197
Page 6C4-2–197
Step Action Yes No
3 1 Switch off the ignition.
2 Disconnect the reverse inhibit solenoid wiring connector.
3 Switch on the ignition with the engine not running.
4 Using Tech 2, command the reverse inhibit solenoid Off.
5 Connect a test lamp between the reverse inhibit solenoid ignition
voltage circuit and the reverse inhibit solenoid control circuit.
Does the test lamp illuminate? Go to Step 6 Go to Step 4
4 Using Tech 2, command the reverse inhibit solenoid On.
Does the test lamp illuminate? Go to Step 8 Go to Step 5
5 Connect a test lamp between the reverse inhibit solenoid ignition
voltage circuit and a known ground.
Does the test lamp illuminate? Go to Step 6 Go to Step 7
6 Test the reverse inhibit solenoid control circuit for an open circuit,
short to ground, high resistance, or short to voltage fault condition.
Refer to 12P Wiring Diagrams for information on electrical fault
diagnosis.
Was any fault found and rectified? Go to Step 10 Go to Step 9
7 Repair the open circuit, short to ground, high resistance, or short to
voltage fault condition in the reverse inhibit solenoid ignition voltage
circuit. Refer to 12P Wiring Diagrams for information on electrical
wiring repair procedures.
Was the repair completed? Go to Step 10 –
8 Replace the reverse inhibit solenoid. Refer to 7B4 Manual
Transmission – GEN IV V8.
Was the repair completed? Go to Step 10 –
9 Replace the ECM. Refer to 6C4-3 Engine Management – GEN IV V8
– Service Operations.
Was the repair completed? Go to Step 10 –
10 1 Using Tech 2, clear the DTCs.
2 Switch Off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC or
within the conditions in the Freeze Frame / Failure Records.
Does P0801 fail this ignition cycle? Go to Step 2 Go to Step 11
11 Using Tech 2, select the DTC display function.
Are there any DTCs displayed?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the engine management system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–198
Page 6C4-2–198
6.40 DTC P0831 and P0833
DTC Descriptor
This diagnostic procedure supports the following DTC
• DTC P0831 Clutch Pedal Switch A Circuit Low Voltage
• DTC P0833 Clutch Pedal Switch B Circuit
Circuit Description
The clutch switch is a normally closed switch, clutch pedal released. The engine control module (ECM) detects an ignition
voltage on the clutch switch circuit when the clutch switch is closed. The ECM detects 0 volts on the clutch switch circuit
when the clutch switch is open, clutch pedal depressed.
When the ECM detects a large number of gear changes without detecting a clutch switch transition, DTC P0833 sets.
Conditions for Running the DTC
DTC P0831, P0833
• No VSS codes set
• Speed greater than 39 km/h
Conditions for Setting the DTC
The ECM has not detected a clutch switch state change when the vehicle speed has gone from 0 km/h to above 39 km/h
and back to 0 km/h.
Conditions for Clearing the DTC
The CKP/CMP sensor correlation DTCs are Type B DTCs. Refer to 1.5 Diagnostic Trouble Codes (DTCs) for action
taken when Type B DTCs set and conditions for clearing Type B DTCs
Additional Information
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Since fault condition in a wiring connector may trigger the DTC, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to Section 12P
Wiring Diagrams for information on electrical fault diagnosis.
• To assist diagnosis, 2 Wiring Diagrams and Connector Charts for the system wiring diagram and connector charts.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
• This test confirms if the scan tool is receiving a clutch switch position signal.
• This step inspects the clutch pedal connector and adjustment.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–199
Page 6C4-2–199
DTC P0831 and P0833
Step Action Values Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch off the ignition for 30 seconds.
2 Start the engine.
3 Allow the engine to reach the normal operating
temperature.
4 Increase the engine speed to 2,000 rpm for 10
seconds.
5 Using Tech 2, select the DTC display function.
Does DTC P0016 fail this ignition cycle? Go to Step 3
Refer to Additional
information in this
Section
3 1 Install a Tech 2.
2 Turn ON the ignition, with the engine OFF.
3 Use the Tech 2 to monitor the clutch pedal position
switch parameter.
4 Apply and release the clutch pedal several times.
Does the Tech 2 indicate a change in state when the
clutch pedal is either applied or released?
Refer to 4.2
Intermittent Fault
Conditions Go to Step 4
4 Inspect the adjustment of the clutch pedal position switch
and the connector.
Does the clutch switch require adjustment or the
connector require service? Go to Step 12 Go to Step 5
5 Using a DMM check for voltage at clutch switch
Does the DMM indicate the specified voltage 11-13V Go to Step 6 Go to Step 8
6 Using a DMM check for ground at clutch switch
Does the DMM indicate the specified resistance <5 ohms Go to Step 7 Go to Step 9
7 Replaced clutch switch
Was the repair completed? Go to Step10
8 Test the clutch switch circuit for an open circuit or high
resistance fault condition. Refer to 12P Wiring Diagrams
for information on electrical fault diagnosis.
Was any fault found and rectified? Go to Step 10
9 Test the clutch switch ground circuit for a short to
voltage, an open circuit or high resistance fault condition.
Refer to 12P Wiring Diagrams for information on
electrical fault diagnosis.
Was any fault found and rectified? Go to Step 10
10 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC.
Does any of the crankshaft / camshaft position
correlation DTCs fail this ignition cycle? Go to Step 2 Go to Step 11
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–200
Page 6C4-2–200
Step Action Values Yes No
11 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–201
Page 6C4-2–201
6.41 DTC P0851, P0852
DTC Descriptor
This diagnostic procedure supports the following DTC
• DTC P0851 Park/Neutral Position (PNP) Switch Circuit Low Voltage
• DTC P0852 Park/Neutral Position (PNP) Switch Circuit High Voltage
Circuit Description
Conditions for Running the DTC
DTC P0851, P0852
DTC run continuously when engine running
Conditions for Setting the DTC
P0851 and P0852
Engine RPM is more than 1000 RPM
TPS is more than 5.5%
Engine Torque more than 75 Nm
Vehicle Speed is more than 32 km/h
Ignition voltage is between 6 and 18 volts
No vehicle speed codes set
No throttle position codes set
No engine torque codes set
Conditions for Clearing the DTC
The Park/Neutral Position Switch DTCs are Type C DTCs. Refer to 1.5 Diagnostic Trouble Codes (DTCs) for action
taken when Type C DTCs set and conditions for clearing Type C DTCs
Additional Information
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• Since fault condition in a wiring connector may trigger the DTC, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to Section 12P
Wiring Diagrams for information on electrical fault diagnosis.
• To assist diagnosis, 2 Wiring Diagrams and Connector Charts for the system wiring diagram and connector charts.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–202
Page 6C4-2–202
DTC P0851 and P0852
Step Action Values Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch off the ignition for 30 seconds.
2 Start the engine.
3 Drive the vehicle above 32 km/h
4 Using Tech 2, select the DTC display function.
Does DTC P0851 or P0852 fail this ignition cycle? Go to Step 3
Refer to Additional
information in this
Section
3 1 Disconnect Park/Netural Switch
2 Turn on ignition engine off.
3 Connect a test lamp from the power wire to earth.
Dose the test lamp illuminate? Go to step 4 Go to step 6
4 1 Using a digital multi meter measure the resistance
on earth wire to known earth.
Is the resistance within the specified value? <5 ohms Go to step 5 Go to step 7
5 Replace Park Netural switch.
Did you complete the replacement. Go to step 8
6 Check Park/Netural Position switch power wire Refer to
12P Wiring Diagrams for information on electrical fault
diagnosis.
Was any fault found and rectified >8-<16 volts Go to step 8 Go to step 2
7 Check Park/Netural Position switch earth wire for
damage. Refer to 12P Wiring Diagrams for information
on electrical fault diagnosis.
Was any fault found and rectified Go to step 8 Go to step 2
8 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–203
Page 6C4-2–203
6.42 DTC P0856
DTC Description
This diagnostic procedure covers DTC P0856 – Traction Control Torque Request Circuit.
Circuit Description
This code determines the presents of the torque request circuit from the TCS system. It will only set with a serial
communication failure.
Diagnostic Table
Refer to 6.47 DTC U0101, U0121 for diagnosis of this code
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–204
Page 6C4-2–204
6.43 DTC P1575
Circuit Description
The extended brake travel switch is mounted on the brake pedal assembly and is a normally closed switch when the
brake pedal is in the rest position. In the rest position, 12 V is supplied to the ECM through circuit 874 to A84 – X1 pin 62.
When the brake pedal is pressed, the switch becomes open and 0 V is supplied to the PCM thus informing the PCM that
the brake pedal has been pressed. The ECM will then cancel the cruise control if it is activated. The power supply to the
switch assembly is protected by fuse F15.
Additional Information
• Refer to Section 12E Cruise Control for details on the extended brake travel switch.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• Refer to 2 Wiring Diagrams and Connector Charts to aid in diagnosis.
• For intermittent fault conditions, refer to 4.2 Intermittent Fault Conditions.
Conditions for Running the DTC
• The engine speed is greater than 700 r.pm.
• The engine operates for greater than 2 seconds.
• The wheel speed is greater than 48 km/h in order to enable the diagnostic. The diagnostic disables when the wheel
speed is below 16 km/h.
• The vehicle is decelerating at more than 16.7 km/s indicating that the brake pedal has been pressed.
Conditions for Setting the DTC
• When the brake pedal is released, the ECM detects a low voltage signal on the extended brake travel switch circuit.
• The above conditions are present for 2 seconds.
Conditions for Clearing the DTC
The Extended Brake Travel Switch Circuit DTC is a Type C DTC. Refer to 1.5 Diagnostic Trouble Codes for action taken
when Type C DTCs set and conditions for clearing Type C DTCs.
DTC P1575 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Observe the Freeze Frame / Failure Record for this DTC.
2 Switch off the ignition for 30 seconds.
3 Operate the vehicle within the conditions for running the DTC or
within the conditions in the Freeze Frame / Failure Records.
4 Using Tech 2 select:
Engine / Diagnostic Trouble Codes / Read DTC Information.
Does DTC P1574 fail this ignition cycle? Go to Step 3
Refer to Additional
Information in this
Section
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–205
Page 6C4-2–205
Step Action Yes No
3 1 Switch the ignition on with the engine not running.
2 Ensure the brake pedal is at rest.
3 Using a test lamp, backprobe between A84 – X1 pin 62 and a
known ground.
Does the test lamp illuminate? Go to Step 4 Go to Step 5
4 Press the brake pedal.
Does the test lamp extinguish? Go to Step 10 Go to Step 7
5 1 Switch the ignition on with the engine not running.
2 Disconnect the cruise control release switch connector.
3 Using a test lamp, probe between harness connector S220 –
X3 pin C and a known ground.
Does the test lamp illuminate? Go to Step 7 Go to Step 6
6 Check circuits 139 and 3 for an open circuit or short to ground.
Was any fault found and rectified? Go to Step 11 —
7 Test the extended brake travel switch, refer to 12E Cruise Control.
Is the extended brake travel switch serviceable? Go to Step 8 Go to Step 9
8 Check circuit 847 for a short to ground, short to voltage or open circuit.
Was any fault found and rectified? Go to Step 11 —
9 Replace the extended brake travel switch, refer to 12E Cruise Control.
Was the repair completed? Go to last step —
10 Replace the PCM. Refer to 6C4-3 Powertrain Management – GEN IV
V8 – Service Operations.
Was the repair completed? Go to Step 11 —
11 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Operate the vehicle within the conditions for running the DTC or
within the conditions in the Freeze Frame / Failure Records.
Does DTC P1574 fail this ignition cycle? Go to Step 2 Go to Step 12
12 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–206
Page 6C4-2–206
6.44 DTC P1682
DTC Descriptor
This diagnostic procedure supports the following DTC:
• DTC P1682 Ignition 1 Switch Circuit 2
Circuit Description
Ignition 1 voltage is supplied through 2 separate circuits. EFI relay supplies one ignition 1 voltage and Start relay supplies
the other ignition 1 voltage.
Conditions for Running the DTC
• The ignition is on.
• DTC P1682 runs continuously when ignition is on.
Conditions for Setting the DTC
The ignition 1 voltage is less than 10 volts for more than 2 seconds.
Conditions for Clearing the DTC
This Serial Data Communication Circuit DTC is a T ype A DTC. Refer to 1.5 Diagnostic Trouble Codes for action taken
when a Type A DTC sets and the conditions required for clearing Type A DTCs.
Action Taken When the DTC Sets
• The ECM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
• The ECM commands system to operate in the reduced engine power mode.
• The under certain conditions the ECM commands the engine off.
• At the time of the failure, the ECM records the operating conditions when the Conditions for Setting the DTC are
met. The ECM stores this information as a Freeze Frame.
Additional Information
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• To assist diagnosis, refer to 2 Wiring Diagrams and Connector Charts for the system wiring diagram and connector
charts
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–207
Page 6C4-2–207
DTC P1682
Step Action Values Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for
running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P1682 fail this ignition cycle? Go to Step 3
Refer to Additional
information in this
Section
3 Did any other DTCs set?
Go to Diagnostic
Trouble Code
(DTC) List -
Vehicle in Vehicle
DTC Information Go to Step 4
4 1 Disconnect X1 connector and connect test lamp
between terminal X1 47 and ground.
2 Turn on ignition.
Does test light illuminate? Go to Step 7 Go to Step 6
5 1 Connect test lamp between terminal X1 19 and
ground
2 Turn on ignition.
Does test light illuminate? Go to Step 7 Go to Step 6
6 Test the ignition 1 voltage circuit for an open or high
resistance.
Was fault found and rectified? Go to Step 9 -
7 Turn ignition off.
Does test light go out?
refer to 4.2
Intermittent Fault
Conditions Go to Step 8
8 Test the ignition 1 voltage circuit for a short to voltage.
Was fault found and rectified? Go to Step 9 -
9 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC.
Does any DTCs fail this ignition cycle? Go to step 2 Go to step 10
10 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–208
Page 6C4-2–208
6.45 DTC P2544
DTC Descriptor
This diagnostic procedure supports the following DTC:
• DTC P2544 Transmission Torque Request Circuit
Circuit Description
To improve shift feel, the transmission control module (TCM) may request that the engine control module (ECM) reduce
engine torque during shift events. When such a request is received, the ECM responds by retarding the base ignition
timing and notifying the TCM that the request has succeeded. If the ECM is unable to comply with the request, the ECM
sends the TCM a message that the request has failed.
The torque reduction request is sent to the ECM through a communication network called the controller area network
(CAN). Two circuits are used to communicate CAN data between the ECM and TCM. A fault in the CAN will not cause
DTC P2544 to set by itself. If a CAN fault occurs, other DTCs will set before DTC P2544.
When the TCM receives a torque reduction failure message from the ECM, then DTC P2544 will set. DTC P2544 is a
type C DTC.
Conditions for Running the DTC
• The engine run time is greater than 5 seconds.
• No other CAN errors are present.
Condition for Setting the DTC
The ECM notifies the TCM that a torque reduction request has failed for 2 seconds.
Conditions for Clearing the DTC
This Serial Data Communication Circuit DTC is a T ype C DTC. Refer to 1.5 Diagnostic T r ouble Codes for action taken
when a Type C DTC sets and the conditions required for clearing Type C DTCs.
Action Taken When the DTC Sets
• The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in
which the Conditions for Setting the DTC are met.
• The TCM turns power off to the PCS.
• The TCM commands maximum line pressure.
• The TCM freezes transmission adaptive functions.
• At the time of the first failure, the TCM records the operating conditions when the Conditions for Setting the DTC
are met. The TCM stores this information as a Failure Record.
• At the time of the second failure, the ECM records the operating conditions when the Conditions for Setting the
DTC are met. The ECM stores this information as a Freeze Fr ame.
• The TCM stores DT C P2544 in TCM history.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the ECM operation.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• To assist diagnosis, refer to 2 Wiring Diagrams and Connector Charts for the system wiring diagram and connector
charts
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–209
Page 6C4-2–209
DTC P2544
Step Action Values Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for
running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P2544 fail this ignition cycle? Go to Step 3
Refer to Additional
information in this
Section
3 Did any other DTCs set?
Go to Diagnostic
Trouble Code
(DTC) List -
Vehicle in Vehicle
DTC Information Go to Step 4
4 Replace the TCM, refer to 7D4 Automatic Transmission –
4L65E – Electrical Diagnosis for replacement, set-up and
programming.
Is the action complete? Go to Step 5
5 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for
running the DTC.
Does any of the serial data communication circuit – TCM
DTCs fail this ignition cycle? Go to step 2 Go to step 8
6 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–210
Page 6C4-2–210
6.46 DTC U0073
DTC Description
This diagnostic procedure supports the following DTC
• DTC U0073 – No Communication with CAN-Bus (High Speed).
Circuit Description
The engine control module (ECM) communicates directly with the control modules connected to the GMLAN serial data
communication circuit through the GMLAN protocol.
However, the body control module (BCM) along with control modules connected to the universal asynchronous receive
and transmit (UART) serial data communication circuit communicates with each other using the UART protocol. Refer to
Section 12J Body Control Module for information on the UART serial data communication circuit.
Since the GMLAN and UART protocols are not compatible, a powertrain interface module (PIM) is integrated into serial
data communication system to serve as a gateway. This gateway allows communication between the two protocols.
Refer to Section 6E4 Powertrain Interface Module – GEN IV V8 for further information on the GMLAN serial data
communication circuit.
DTC U0073 sets if the ECM detects a fault condition in the serial data communication circuit.
To aid diagnosis, refer to 2 Wiring Diagrams and Connector Charts for the system wiring diagram and connector charts.
Conditions for Running the DTC
DTC U0073
Runs continuously when the following conditions are met:
• The ignition voltage is 10.0 – 16.0 V.
• The vehicle power mode requires serial data communication.
Conditions for Setting the DTC
The ECM detects a specified number of transmitted messages are not valid.
Conditions for Clearing the DTC
The Serial Data Communication Circuit DTCs are Type B DTCs. Refer to 1.5 Diagnostic Trouble Codes for action taken
when a Type B DTC sets and conditions for clearing Type C DTCs.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the ECM operation.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• To assist diagnosis, refer to 2 Wiring Diagrams and Connector Charts for the system wiring diagram and connector
charts.
Test Description
The following number refers to the step numbers in the diagnostic table:
1 The following tests are included in the Diagnostic System Check.
• Tests the integrity of the GMLAN serial data communication circuit.
• Tests for fault conditions on the vehicle theft deterrent system stored in the BCM.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–211
Page 6C4-2–211
DTC U0073 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC U0073 fail this ignition cycle? Go to Step 3
Refer to Additional
Information in this
Section
3 Replace the ECM. Refer to 6C4-3 Engine Management – GEN IV V8
– Service Operations.
Was the repair completed? Go to Step 4 —
4 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Does DTC U0073 fail this ignition cycle? Go to Step 2 Go to Step 5
5 Using Tech 2, select the DTC display function.
Are there any DTCs displayed?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–212
Page 6C4-2–212
6.47 DTC U0101, U0121
DTC Description
This diagnostic procedure supports the following DTC:
• DTC U0101 – CAN-Bus No Communication With TCM (Transmission Control Module)
• DTC U0121 - CAN Bus No Communication with ABS (Anti Lock Brake System)
Circuit Description
The Engine Control Module (ECM) communicates directly with the Transmission Control Module (TCM) and other control
modules connected to the GMLAN serial data communication circuit through the GMLAN protocol.
However, the Body Control Module (BCM) along with control modules connected to the universal asynchronous receive
and transmit (UART) serial data communication circuit communicates with each other through the UART protocol. Refer
to Section 12J Body Control Module for information on the UART serial data communication circuit.
Since the GMLAN and UART protocols are not compatible, a Powertrain Interface Module (PIM) is integrated into serial
data communication system to serve as a gateway. This gateway allows communication between the two protocols.
Refer to Section 6E4 Powertrain Interface Module – GEN IV V8 for further information on the GMLAN serial data
communication circuit.
A serial data communication circuit – TCM DTC sets if the ECM detects an invalid signal from the T CM.
Conditions for Running the DTC
DTC U0101
Runs continuously when the following conditions are met:
• The ignition is on for longer than 3 seconds.
• The ignition voltage is 10.0 – 16.0 V.
DTC U0121
No information available at time of publication.
Conditions for Setting the DTC
The ECM did not receive a valid signal from the TCM within the specified time frame.
Conditions for Clearing the DTC
This Serial Data Communication Circuit DTC is a T ype C DTC. Refer to 1.5 Diagnostic T r ouble Codes for action taken
when a Type C DTC sets and the conditions required for clearing Type C DTCs.
Additional Information
• Refer to Section 6C4-1 Engine Management – GEN IV V8 – General Information for details of the ECM operation.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to
Section 12P Wiring Diagrams for information on electrical fault diagnosis.
• For an intermittent fault condition, refer to 4.2 Intermittent Fault Conditions.
• To assist diagnosis, refer to 2 Wiring Diagrams and Connector Charts for the system wiring diagram and connector
charts.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–213
Page 6C4-2–213
Test Description
The following number refers to the step numbers in the diagnostic table:
1 The following tests are included in the Diagnostic System Check.
• Tests the integrity of the GMLAN serial data communication circuit.
• Tests for fault conditions on the vehicle theft deterrent system stored in the BCM.
DTC P0864 and U0101 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2
Refer to
3.4 Diagnostic
System Check
2 1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC U0101 fail this ignition cycle? Go to Step 3
Refer to Additional
Information in this
Section
3 Using Tech 2, attempt to communicate with the PIM.
Does the PIM failed to communicate?
Refer to 6E4
Powertrain Interface
Module – GEN IV
V8 Go to Step 4
4 Are DTCs also set in the PIM? Refer to 6E4
Powertrain Interface
Module – GEN IV
V8 Go to Step 5
5 Are DTCs that may trigger a fault condition in the serial data
communication circuit also set in the TCM? Refer to 7D2
Automatic
Transmission –
4L65E – Electrical
Diagnosis Go to Step 6
6 Replace the TCM, refer to 7D4 Automatic Transmission – 4L65E –
On-vehicle Servicing.
Was the repair completed? Go to Step 7 —
7 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Does any of the serial data communication circuit – TCM DTCs fail
this ignition cycle? Go to Step 2 Go to Step 8
8 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs?
Go to the
appropriate DTC
Table System OK
When all diagnosis and repairs are completed, check the system for correct operation.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–214
Page 6C4-2–214
7 V8 Engine – Tech 2 Functions
7.1 Introduction
Do not use a Tech 2 that displays faulty data;
have the Tech 2 repaired. The use of a faulty
Tech 2 can result in misdiagnosis and the
unnecessary replacement of parts.
From the Main Menu, having selected Diagnostics / 2006 VZ and WL Series / Engine, the Tech 2 functions for the
GEN VI V8 engine, include:
F0: Diagnostic Trouble Codes
F1: Data Display
F2: OBD Data
F3: Snapshot
F4: Actuator Test
F5: Additional Functions
F6: Programming
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–215
Page 6C4-2–215
7.2 Tech 2 Functions
F0: Diagnostic Trouble Codes
When this test mode is initiated, DTCs stored by the ECM can be displayed or cleared. When entered, there are three
additional modes for selection:
F0: Read DTC Information: All DTCs stored in the ECM will be displayed.
F1: Clear Engine & Transmission DTCs: Clears all current DTCs in the ECM and TCM memories.
F2: DTC Information: Shows information about relevant DTCs.
F3: Freeze Frame: Shows the Freeze Frame information. Freeze Frames are types of snapshots stored in the
ECM memory.
Refer to Section 0C Tech 2 for more specific information relating to this selection.
F1: Data Display
• Use the Tech 2 Data List under the following conditions:
• The Diagnostic System Check – GEN IV Engine has been completed.
• The On-Board Diagnostics are functioning correctly.
• No DTCs are present.
NOTE
• Tech 2 values from an engine that is
operating correctly may be used for
comparison with the engine you are
diagnosing. The Tech 2 engine data lists
represent typical values that would be seen
on a normal operating engine.
• The Tech 2 Data Definitions list that follows
the Data Lists, is arranged in alphabetical
order and contains a brief description of all of
the engine related parameters that are
available.
The following ‘typical’ Tech 2 values were recorded under the following conditions:
Ignition ON:
• Engine stopped, ignition in the ON position.
• Closed throttle.
• Transmission selector in the Park position (Automatic
Transmission) or Neutral (Manual Transmission.
• Engine, transmission at ambient temperature.
• Accessories are OFF.
• Brake pedal is not applied.
Engine Running
• Engine running.
• Closed throttle.
• Transmission selector in the Park position (Automatic
Transmission) or Neutral (Manual Transmission.
• Engine, transmission at normal operating temperature.
• Accessories are OFF.
• Brake pedal not applied.
NOTE
The values quoted in the following data lists are
only intended to provide the Technician with an
indication of the values to be expected.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–216
Page 6C4-2–216
When ‘F1: Data Display’ is selected, there are 13 data lists provided, that can save time when diagnosing symptomatic
conditions.
• Engine Data
• EVAP Data
• Fuel Trim Data
• O2 Sensor Data
• Ignition Data
• Misfire Data
• TAC Data (Throttle Actuator Control)
• Instrument Data
• Cruise/Traction Data
• Cooling/HVAC Data
• Electrical/Theft Data
• ODM Data (Output Driver Module)
• Transmission Data
F2: OBD Data
In this test mode, Tech 2 displays engine management data parameters relating to the OBD (On Board Diagnostic) for
the engine being diagnosed.
F3: Snapshot
In this test mode, Tech 2 captures data before and after a snapshot triggering event that may or may not set a DTC. For
more specific information relating to the use of this Tech 2 feature, refer to Section 0C Tech 2.
F4: Actuator Test
In this test mode, Tech 2 performs software override commands to the ECM, to assist in problem isolation during
diagnostics. When entering this mode, there are 10 actuators that can be tested for operational integrity. The 12 tests
available are:
• Fan Relays
• Fuel Pump Relay Test
• Electronic Throttle Control Test
• A/C Relay Test
• Alternator L Terminal
• EVAP Purge Solenoid
• Engine Speed Control
• Starter Motor Relay Test
• Malfunction Indicator (MI) Test
• Fuel Injector Balance
F5: Additional Functions
When this selection is made from the Tech 2 screen, an additional two choices are provided:
F0: System Identification: In this mode, Tech 2 will display the engine identification screen.
F1: Security Information: When selected, this mode displays various engine management data parameters
relating to the security system.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–217
Page 6C4-2–217
F6: Programming
Within this selection, there are five programming selections available:
F0: Learn Crank Angle Sensing Error
F1: BCM Link to ECM/PIM
F2: Reset ECU
F3: Reset Engine Oil Life
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–218
Page 6C4-2–218
7.3 GEN IV V8 Engine Data Lists
Engine Data
Tech 2 Display Units Displayed Ignition On Engine Running
Engine Speed RPM 0 1088
Desired Engine Idle Speed RPM 680 1090
Coolant Temperature °C 50 39
Intake Air Temperature °C 29 27
Ambient Temperature °C
Cold Start Up Yes_No
Mass Air Flow Sensor Hz
Mass Air Flow g/s 0.00 8.01
Calculated Air Flow g/s
Engine Load % 1.00 25
Calculated Pedal Position % 0 0
Calculated Throttle Position % 5 4
Manifold Absolute Pressure kPa
Barometric Pressure KPa 102 102
Actual Air/Fuel Ratio 0.0:1
Fuel System Status Closed Loop_Open
Loop
B1 Average Injection Time (Bank 1) ms
B2 Average Injection Time (Bank 2) ms
B1S1 Heated O2 Sensor (Bank 1 Sensor 1) mV 438 455
B1S2 Heated O2 Sensor (Bank 1 Sensor 2) mV 438 447
B2S1 Heated O2 Sensor (Bank 2 Sensor 1) mV 438 455
B2S2 Heated O2 Sensor (Bank 2 Sensor 2) mV 438 455
B1 Short Term Fuel Trim (Bank 1) % 0 0
B2 Short Term Fuel Trim (Bank 2) % 0 –1
B1 LTFT Cruise/Acceleration (Bank 1 Long Term Fuel
Trim) % 0 0
B2 LTFT Cruise/Acceleration (Bank 2 Long Term Fuel
Trim) % 0 0
Fuel Trim Learn Disabled_Enabled
Fuel Trim Cell Index
Power Enrichment No_Yes
Dec. Fuel Cut-off (Deceleration) Inactive_Active
EVAP Purge Solenoid (Evaporative Emission) % 0 0
Fuel Level %
Spark Advance °CA 0 8
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–219
Page 6C4-2–219
Tech 2 Display Units Displayed Ignition On Engine Running
Crankshaft Speed RPM
Camshaft Sensor Engine Speed RPM
Ignition Voltage V
Ignition Accessory Signal Off / On On On
Engine Control Ignition Relay Off / On On On
Engine Control Ignition Relay Feedback V 11.8 13.9
Malfunction Indicator Lamp (MIL) Off / On / Flashing On Off
MIL Requested by DTC (Malfunction Indicator) No_Yes
Malfunction Indicator Lamp (MIL) Circuit Status Passed_Failed_Inco
mplete
Fuel Pump Relay Off / On Off On
Fuel Pump Relay Circuit Status Passed_Failed_Inco
mplete
Transmission Gear P-N Gear
Clutch Pedal Switch Inactive_Active
A/C Relay (Air Conditioning) Off_On
Oil Level Normal_Low
Engine Oil Pressure kPa
5V Reference Voltage Circuit 1 Status Valid_Invalid
5V Reference Voltage Circuit 2 Status Valid_Invalid
Vehicle Speed Km/h
Number Of Warm Ups Since DTC Cleared Counts
Warm Ups Without Emission Related DTCs (w/o unit)
Warm Ups Without Non-Emission Related DTCs (w/o unit)
Distance Since DTC Cleared Km
Engine Runtime
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–220
Page 6C4-2–220
EVAP Data
Tech 2 Display Units Displayed Ignition On Engine Running
EVAP Purge Solenoid (Evaporative Emission) % 0 0
EVAP Purge Solenoid Valve Circuit Status (Evaporative
Emissions)
Fuel Level L 16 11
Fuel Level Sensor V 2.37 2.39
Engine Speed RPM 0 598
Desired Engine Idle Speed RPM 680 600
Coolant Temperature °C 41 86
Start Up ECT (Engine Coolant Temperature) °C 41 34
Cold Start Up Yes_No
Intake Air Temperature °C 33 26
Mass Air Flow Sensor V 1.0 1.2
Mass Air Flow g/s
Engine Load % 100 23
Calculated Pedal Position % 0 0
Calculated Throttle Position % 5 1
Manifold Absolute Pressure
Barometric Pressure KPa 102 102
Fuel System Status Open / Closed Open Closed
B1S1 Heated O2 Sensor (Bank 1 Sensor 1) :1 (=Lambda) 0.99 23
B2S1 Heated O2 Sensor (Bank 2 Sensor 1) :1 (=Lambda) 0.99 16
B1 Short Term Fuel Trim (Bank 1) % 0 –1
B2 Short Term Fuel Trim (Bank 2) %
B1S2 Heated O2 Sensor (Bank 1 Sensor2)
B2S2 Heated O2 Sensor (Bank 2 Sensor 2)
B1 LTFT Idle/Deceleration (Bank 1 Long Term Fuel
Trim) % 0 1
B1 LTFT Cruise/Acceleration (Bank 1 Long Term Fuel
Trim) % 0 0
Fuel Trim Learn % 0 4
Fuel Trim Cell % 0 0
Ignition Voltage V
5V Reference Voltage Circuit 1 Status Valid Invalid
5V Reference Voltage Circuit 2 Status Valid Invalid
MIL Requested by DTC (Malfunction Indicator Lamp) No_Yes
Malfunction Indicator Lamp (MIL) Off_On
Vehicle Speed Km/h
Engine Runtime 00:00:00 h:m:s
Calculated Air Flow g/s
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–221
Page 6C4-2–221
Fuel Trim Data
Tech 2 Display Units Displayed Ignition On Engine Running
B1 Short Term Fuel Trim (Bank 1) %
B2 Shot Term Fuel Trim (Bank 2) %
B1 LTFT Cruise/Acceleration (Bank1 Long Term Fuel
Trim) %
B2 LTFT Cruise/Acceleration (Bank2 Long Term Fuel
Trim) Enable _Disable
Fuel Trim Learn Index
Fuel Trim Cell Closed Loop _ Open
Loop
Fuel System Status mV
B1S1 Heated O2 Sensor (Bank 1 Sensor 1) mV
B1S2 Heated O2 Sensor (Bank 1 Sensor 2) mV
B2S1 Heated O2 Sensor (Bank 2 Sensor 1) mV
B2S2 Heated O2 Sensor (Bank 2 Sensor 2) mV
B1 Average Injection Time (Bank 1) Ms
B2 Average Injection Time (Bank 2) Ms
Hot Open Loop Inactive_Active
Catalyst Protection Mode No_Yes
Power Enrichment No_Yes
Dec. Fuel Cut-off (Deceleration) Inactive_Active
EVAP Purge Solenoid (Evaporative Emissions) %
Engine Speed RPM
Coolant Temperature °C
Intake Air Temperature °C
Start Up ECT (Engine Coolant Temperature) °C
Mass Air Flow Sensor Hz
Mass Air Flow g/s
Calculated Air Flow g/s
Engine Load %
Calculated Pedal Position %
Calculated Throttle Position %
Manifold Absolute Pressure kPa
Barometric Pressure kPa
Actual Air/Fuel Ratio 0.0:1
Spark Advance °CA
Ignition Voltage V
MAF Performance Test (Mass Air Flow) Okay_Fail
MIL Requested by DTC (Malfunction Indicator Lamp) No_Yes
B1 Catalyst Temperature (Bank 1) °C
B2 Catalyst Temperature (Bank 2) °C
Vehicle Speed Km/h
Engine Runtime 00:00:00_h:m:s
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–222
Page 6C4-2–222
O2 Sensor Data
Tech 2 Display Units Displayed Ignition On Engine Running
Fuel Trim Status Closed Loop_Open
Loop
B1S1 Heated O2 Sensor (Bank 1 Sensor 1) mV
B1S2 Heated O2 Sensor (Bank 1 Sensor 2) mV
B2S1 Heated O2 Sensor (Bank 2 Sensor 1) mV
B2S2 Heated O2 Sensor (Bank 2 Sensor 2) mV
B1 Short Term Fuel Trim (Bank 1) %
B2 Short Term Fuel Trim (Bank 2) %
B1 LTFT Cruise/Acceleration (Bank 1 Long Term Fuel
Trim) %
B2 LTFT Cruise/Acceleration (Bank 2 Long Term Fuel
Trim) %
B1 Average Injection Time (Bank1) ms
B2 Average Injection Time (Bank1) ms
Commanded B1S1 Heated O2 Sensor Heater (Bank 1
Sensor 1) %
B1S1 Heated O2 Sensor Heater (Bank 1 Sensor 1) Active_Inactive
Commanded B1S2 Heated O2 Sensor Heater (Bank 1
Sensor 2) %
B1S2 Heated O2 Sensor Heater (Bank 1 Sensor 2) Active_Inactive
Commanded B2S1 Heated O2 Sensor Heater (Bank 2
Sensor 1) %
B2S1 Heated O2 Sensor Heater (Bank 2 Sensor 1) Active_Inactive
Commanded B2S2 Heated O2 Sensor Heater (Bank 2
Sensor 2) %
B2S2 Heated O2 Sensor Heater (Bank 2 Sensor 2) Active_Inactive
B1S1 Heated O2 Sensor Heater (Bank 1 Sensor 1) mA
B1S1 Heated O2 Sensor Heater (Bank 1 Sensor 1) mA
B1S1 Heated O2 Sensor Heater (Bank 1 Sensor 1) mA
B1S1 Heated O2 Sensor Heater (Bank 1 Sensor 1) mA
B1S1 Heated O2 Sensor Heater Circuit Status (Bank 1
Sensor 1) Pass_Fail_Incomple
te
B1S2 Heated O2 Sensor Heater Circuit Status (Bank 1
Sensor 2) Pass_Fail_Incomple
te
B2S1 Heated O2 Sensor Heater Circuit Status (Bank 2
Sensor 1) Pass_Fail_Incomple
te
B2S2 Heated O2 Sensor Heater Circuit Status (Bank 2
Sensor 2) Pass_Fail_Incomple
te
Hot Open Loop Inactive_Active
Catalyst Protection Mode No_Yes
Power Enrichment No_Yes
Dec. Fuel Cut Off Inactive_Active
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–223
Page 6C4-2–223
Tech 2 Display Units Displayed Ignition On Engine Running
EVAP Purge Solenoid %
Engine Speed RPM
Coolant Temperature °C
Intake Air Temperature °C
Start Up ECT °C
Start Up IAT °C
Mass Air Flow Sensor Hz
Mass Air Flow g/s
Calculated Air Flow g/s
Engine Load %
Calculated Pedal Position %
Calculated Throttle Position %
Manifold Absolute Pressure kPa
Barometric Pressure kPa
Actual Air Fuel Ratio 0.0:1
Spark Advance °CA
Ignition Voltage V
Vehicle Speed Km/h
Mi Requested by DTC No_Yes
Engine Runtime 00:00:00 h:m:s
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–224
Page 6C4-2–224
TAC Data (Throttle Actuator Control)
Tech 2 Display Units Displayed Ignition On Engine Running
Reduced Engine Power Inactive / Active Inactive Inactive
Calculated Pedal Position % 0 0
Desired Throttle Position % 4 1
Calculated Throttle Position % 5 1
APP Sensor 1-2 Correlation (Accelerator Pedal Position
Sensor) Okay / Fault Okay Okay
APP Sensor 1 (Accelerator Pedal Position) %
APP Sensor 1 (Accelerator Pedal Position) V 1.02 1.02
APP Sensor 2 (Accelerator Pedal Position) %
APP Sensor 2 (Accelerator Pedal Position) V 0.47 0.47
Calculated APP Sensor 1 (Accelerator Pedal Position) %
Calculated APP Sensor 1 (Accelerator Pedal Position) %
TP Sensor 1-2 Correlation (Throttle Position) Okay_Not Okay
TP Sensor 1 (Throttle Position) %
TP Sensor 1 (Throttle Position) V 0.73 0.57
TP Sensor 2 (Throttle Position) %
TP Sensor 2 (Throttle Position) V 4.27 4.43
Calculated TP Sensor 1 (Throttle Position) V
Calculated TP Sensor 2 (Throttle Position) V
TP Sensor 1 Learned Lower Position (Throttle Position) V 0.53 0.53
TP Sensor 2 Learned Lower Position (Throttle Position) V 4.49 4.49
5V Reference Voltage Circuit 1 Status Valid_Invalid
5V Reference Voltage Circuit 2 Status Valid_Invalid
Wide Open Throttle No_Yes
TAC Motor (Throttle Actuator Control) Enabled_Disabled
TAC Forced Engine Shut Down No_Yes
TAC Motor Command %
Cruise Control Active No_Yes
Brake Lamp Switch Inactive_Active
Extended Travel Brake Pedal Switch Inactive_Active
Clutch Pedal Switch Inactive_Active
Engine Speed RPM
Desired Engine Idle Speed RPM
Coolant Temperature
Intake Air Temperature
Calculated Air Flow g/s
Mass Air Flow g/s
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–225
Page 6C4-2–225
Manifold Absolute Pressure kPa
Engine Load %
Ignition Voltage V
Ignition Accessory Signal On_Off
Engine Control Ignition Relay On_Off
Engine Control Ignition Relay Feed Back V
A/C Relay (Air Conditioning) On_Off
Request Torque Nm
Actual Torque Nm
Vehicle Speed Km/h
MIL Requested by DTC (Malfunction Indicator Lamp) No_Yes
Engine Runtime 00:00:00_h:m:s
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–226
Page 6C4-2–226
Cooling/HVAC Data
Tech 2 Display Units Displayed Ignition On Engine Running
Coolant Temperature °C 37 100
Intake Air Temperature °C 32 30
Fan Relay 1 Off / On Off Off
Fan Relay 2 and 3 Off / On Off Off
A/C Request No / Yes No No
A/C Relay (Air Conditioning) Off / On Off Off
A/C Relay Circuit Status (Air Conditioning) Inactive_Active
A/C Pressure Sensor (Air Conditioning) V 1.0 1.5
A/C Pressure Sensor (Air Conditioning) KPa 732.55 1121.25
A/C Cut-off Mode (Air Conditioning) Inactive / Pressure /
Max. Acceleration /
Active Inactive Inactive
Start Up ECT (Engine Coolant Temperature) °C 37 34
Start Up IAT (Intake Air Temperature) °C –48 30
Engine Oil Temperature °C
Transmission Oil Temperature °C
Engine Load % 100 19
Hot Open Loop Inactive_Active
Spark Advance °CA
Total Knock Retard °CA
5V Reference Voltage Circuit 1 Status Valid_Invalid
5V Reference Voltage Circuit 1 Status Valid_Invalid
Ignition Voltage V
A/C Disengagement 1st History Refer List Below High
Pressure Engine Speed
A/C Disengagement 2nd History Refer List Below High
Pressure High Pressure
A/C Disengagement 3rd History Refer List Below High
Pressure High Pressure
A/C Disengagement 4th History Refer List Below High
Pressure High Pressure
A/C Disengagement 5th History Refer List Below High
Pressure High Pressure
A/C Disengagement 6th History Refer List Below High
Pressure High Pressure
A/C Disengagement 7th History Refer List Below High
Pressure High Pressure
A/C Disengagement 8th History Refer List Below High
Pressure High Pressure
Engine Speed RPM 0 601
Vehicle Speed km/h 0 0
Engine Runtime h:m:s 00:00:00 00:19:15
A/C Disengagement History Units
High Pressure / Engine Speed / Low Battery / Stall Prevention / Full Load / Performance / Engine T emp / Not Present
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–227
Page 6C4-2–227
Cruise/Traction Data
Tech 2 Display Units Displayed Ignition On Engine Running
Cruise Control Switch Inactive / Active Inactive Inactive
Cruise Control Active No / Yes No No
Cruise Set / Decel Switch Inactive / Active Inactive Inactive
Cruise Resume/Acceleration Switch Inactive / Active Inactive Inactive
Cruise Control Disengagement Reason Refer List Below Brake Brake
CC Disengagement 1st History (Cruise Control) Refer List Below Brake Brake
CC Disengagement 2nd History (Cruise Control) Refer List Below Brake Brake
CC Disengagement 3rd History (Cruise Control) Refer List Below Brake Brake
CC Disengagement 4th History (Cruise Control) Refer List Below Brake Brake
CC Disengagement 5th History (Cruise Control) Refer List Below Brake Brake
CC Disengagement 6th History (Cruise Control) Refer List Below Brake Brake
CC Disengagement 7th History (Cruise Control) Refer List Below Brake Brake
CC Disengagement 8th History (Cruise Control) Refer List Below Brake Brake
Vehicle Speed km/h 0 0
Brake Lamp Switch Inactive / Active Inactive Inactive
Brake Switch Signal Status Valid / Invalid Valid Valid
Initial Brake Apply Signal Inactive / Active Inactive Inactive
Extended Travel Brake Pedal Switch Inactive / Active Inactive Inactive
Calculated Pedal Position % 0 0
Desired Throttle Position % 4 1
Calculated Throttle Position % 5 1
Engine Speed RPM 0 599
(2) Actual Gear -1- / -2- / -3- / -4- / -
5- / -P/N- / -R- /
-Invalid- -P/N- -P/N-
Spark Advance °CA 0 13
Traction Control Active / Inactive Inactive Inactive
Requested Torque % 99 99
Cruise Control Disengagement Reason Units
Brake / Cancel / Clutch Diseng / Coasting / Throttle Control / Max. Acceleration / High Decel / High Speed / Illegal
Mode / Low Speed / Not Present / Off / OverSpeed / ECM / Command Error / Traction / Ignition Off / Data Error /
System Error / Engine Runtime / Engine Speed / DTCs Set / Injection Stop / First Gear / Accel Pedal Pos / Voltage Low
/ Manual Neutral / Over Limit
(1)Automatic Transmission Only (2) Manual Transmission Only
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–228
Page 6C4-2–228
Electrical/Theft Data
Tech 2 Display Units Displayed Ignition On Engine Running
Ignition On Signal Off / On On On
Ignition Accessory Signal Off / On On On
Engine Control Ignition Relay Off / On On On
Engine Control Ignition Relay Feedback V 11.6 14.2
Crank Request Inactive / Active Inactive Inactive
Starter Relay Off / On Off Off
(2) Transmission Gear P/N / In Gear P-N P-N
(2) Actual Gear -1- / -2- / -3- / -4- / -
5- / -P/N- / -R- /
-Invalid- -P/N- -P/N-
(2) Actual Gear Valid / Invalid Valid Valid
Alternator L Terminal Duty Cycle % 0 99
Engine Speed RPM 0 599
ECM Immobilized No / Yes No No
(1)Automatic Transmission Only (2) Manual Transmission Only
Instrument Data
Tech 2 Display Units Displayed Ignition On Engine Running
Ignition On Signal Off / On On On
Ignition Accessory Signal Off / On On On
Vehicle Speed km/h 0 0
Engine Speed RPM 0 593
(2) Actual Gear -1- / -2- / -3- / -4- / -
5- / -P/N- / -R- /
-Invalid- -P/N- -P/N-
Coolant Temperature °C 36 105
Fuel Level L 17 11
Fuel Level Sensor V 2.37 2.39
Engine Oil Pressure Sensor Low / High High High
Engine Oil Pressure KPa 24 120
Engine Oil Life Remaining % 96 96
Oil Level Normal / Low Normal Normal
Oil Temperature Sensor °C 34 89
Malfunction Indicator (MI) Off / On / Flashing On Off
Cruise Control Active No / Yes No No
Reduced Engine Power Inactive / Active Inactive Inactive
ECM Immobilized No / Yes No No
(1)Automatic Transmission Only (2) Manual Transmission Only
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–229
Page 6C4-2–229
ODM Data (Output Driver Module)
Tech 2 Display Units Displayed Ignition On Engine Running
A/C Relay Status OK / Fault /
Undefined Status Undefined
Status Undefined
Status
Cylinder 1 Injector Circuit Status OK / Fault /
Undefined Status Undefined
Status OK
Cylinder 2 Injector Circuit Status OK / Fault /
Undefined Status Undefined
Status OK
Cylinder 3 Injector Circuit Status OK / Fault /
Undefined Status Undefined
Status OK
Cylinder 4 Injector Circuit Status OK / Fault /
Undefined Status Undefined
Status OK
Cylinder 5 Injector Circuit Status OK / Fault /
Undefined Status Undefined
Status OK
Cylinder 6 Injector Circuit Status OK / Fault /
Undefined Status Undefined
Status OK
EVAP Purge Solenoid Valve Circuit Status (Evaporative
Emission) OK / Fault /
Undefined Status Undefined
Status OK
(1) B1 Exhaust Camshaft Position Solenoid Valve Circuit
Status (Bank 1) OK / Fault /
Undefined Status Undefined
Status OK
B1 Intake Camshaft Position Solenoid Valve Circuit
Status (Bank 1) OK / Fault /
Undefined Status Undefined
Status OK
(1) B2 Exhaust Camshaft Position Solenoid Valve Circuit
Status (Bank 2) OK / Fault /
Undefined Status Undefined
Status OK
B2 Intake Camshaft Position Solenoid Valve Circuit
Status (Bank 2) OK / Fault /
Undefined Status Undefined
Status OK
Fan Relay 1 Circuit Status OK / Fault /
Undefined Status Undefined
Status Undefined
Status
Fan Relay 2 and 3 Circuit Status OK / Fault /
Undefined Status Undefined
Status Undefined
Status
Fuel Pump Relay Circuit Status OK / Fault /
Undefined Status Undefined
Status Undefined
Status
B1S1 Heated O2 Sensor Heater Circuit Status (Bank 1
Sensor 1) OK / Fault /
Undefined Status Undefined
Status Undefined
Status
B1S2 Heated O2 Sensor Heater Circuit Status (Bank 1
Sensor 2) OK / Fault /
Undefined Status Undefined
Status Undefined
Status
B2S1 Heated O2 Sensor Heater Circuit Status (Bank 2
Sensor 1) OK / Fault /
Undefined Status Undefined
Status Undefined
Status
B2S2 Heated O2 Sensor Heater Circuit Status (Bank 2
Sensor 2) OK / Fault /
Undefined Status Undefined
Status Undefined
Status
IMRC Solenoid Circuit Status (Intake Manifold Runner
Control) (1) OK / Fault /
Undefined Status Undefined
Status Undefined
Status
Malfunction Indicator Lamp (MIL) Circuit Status OK / Fault /
Undefined Status Undefined
Status Undefined
Status
Starter Relay Circuit Status OK / Fault /
Undefined Status Undefined
Status Undefined
Status
Engine Runtime h:m:s 00:00:00 00:23:02
(1)Automatic Transmission Only (2) Manual Transmission Only
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–230
Page 6C4-2–230
Misfire Data
Tech 2 Display Units Displayed Ignition On Engine Running
Cycles of Misfire Counts 0 0 – 3000
(Increments)
Total Misfire Counts 0 0
Misfire Current Cyl. #1 Counts 0 0
Misfire Current Cyl. #2 Counts 0 0
Misfire Current Cyl. #3 Counts 0 0
Misfire Current Cyl. #4 Counts 0 0
Misfire Current Cyl. #5 Counts 0 0
Misfire Current Cyl. #6 Counts 0 0
Misfire History Cyl. #1 Counts 0 0
Misfire History Cyl. #2 Counts 0 0
Misfire History Cyl. #3 Counts 0 0
Misfire History Cyl. #4 Counts 0 0
Misfire History Cyl. #5 Counts 0 0
Misfire History Cyl. #6 Counts 0 0
Misfire History Cyl. #7 Counts 0 0
Misfire History Cyl. #8 Counts 0 0
A/C Relay (Air Conditioning) Off / On Off Off
Barometric Pressure KPa 102 102
B1 Catalyst Temperature (Bank 1) °C 300 300
B2 Catalyst Temperature (Bank 2) °C 300 300
Catalyst Protection Mode Inactive / Active Inactive Inactive
(2) Transmission Gear P-N / In Gear P-N P-N
Coolant Temperature °C 36 101
Engine Load % 100 19
Engine Oil Pressure KPa 24 120
Engine Runtime h:m:s 00:00:00 00:37:48
Ignition On Signal Off / On On On
Injection Time Cylinder 1 Ms 0.0 1.9
Injection Time Cylinder 2 Ms 0.0 1.9
Injection Time Cylinder 3 Ms 0.0 1.9
Injection Time Cylinder 4 Ms 0.0 1.9
Injection Time Cylinder 5 Ms 0.0 1.9
Injection Time Cylinder 6 Ms 0.0 1.9
B1 Average Injection Time (Bank 1) Ms 0.0 1.9
B2 Average Injection Time (Bank 2) Ms 0.0 1.9
Mass Air Flow Sensor V 1.0 1.1
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–231
Page 6C4-2–231
Tech 2 Display Units Displayed Ignition On Engine Running
Mass Air Flow g/s 0.00 2.92
Power Enrichment No / Yes No No
Spark Advance °CA 0 13
Calculated Throttle Position % 5 1
Vehicle Speed km/h 0 0
Volumetric Efficiency % 99 13
(1)Automatic Transmission Only (2) Manual Transmission Only
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–232
Page 6C4-2–232
7.4 Tech 2 Data Definitions
NOTE
This listing is arranged in alphabetical order and
defines each parameter shown in the Data Lists.
A/C Cut-off Mode (Air Conditioning): This parameter displays whether the control module is commanding the A/C
compressor clutch relay OFF for a number of reasons, among which is; operating pressure outside given parameters or
throttle position at wide open throttle (WOT).
A/C Disengagement 1 – 8 History: The parameter displays the last 8 air conditioning (A/C) compressor disengages in
order from 1 to 8 with 8 being the most recent. There are 8 possible causes listed for the A/C compressor to disengage;
High Pressure, Engine Speed, Battery Voltage, Stall Prevention, Full Load, Performance, Engine Temperature or Signal
not Present. Any of these causes need to be outside calibrated values, to cause the A/C to disengage.
A/C Pressure Sensor (Air Conditioning): This parameter displays the voltage from the A/C high side pressure sensor
signal circuit to the control module.
A/C Pressure Sensor (Air Conditioning): This parameter displays the pressure in kPa from the A/C high side pressure
sensor signal circuit to the control module.
A/C Relay (Air Conditioning): This parameter displays the state of the A/C clutch relay control circuit, either as ‘ON’ or
‘OFF’.
A/C Relay Status: This parameter displays the state of the A/C request input to the control module from the heating,
ventilation, and air conditioning (HVAC) controls.
A/C Request: Represents the commanded state of the A/C clutch control relay. Clutch should be engaged when ON is
displayed.
Actual Gear: This parameter displays the transmission range input to the control module, determined directly from the
decoding of the PRNDL – A, B, C, and P inputs from the transmission internal mode switch (IMS).
Actual Gear: Based on the evaluation of the PRNDL – A, B, C, and P inputs, the ECM determines whether the
parameter is valid or invalid.
Alternator L Terminal Duty Cycle: This parameter displays the ECMs commanded state of the voltage regulator on the
alternator, expressed as a percentage from 0 to 100.
APP Sensor 1 (Accelerator Pedal Position): This parameter displays the actual voltage on the APP sensor 1 signal
circuit as measured by the ECM, that can range from 0.9 – 4.5 volts.
APP Sensor 2 (Accelerator Pedal Position): This parameter displays the actual voltage on the APP sensor 1 signal
circuit as measured by the ECM, that can range from 0.45 – 2.25 volts.
APP Sensor 1 and 2 Correlation (Accelerator Pedal Position): This parameter displays ‘Okay’ under normal operating
conditions or ‘Fault’ if the control module detects the signal voltage from APP sensor 1 that is not in the correct
relationship to APP sensor 2.
Average Injection Time (Bank 1 or Bank 2): This parameter displays the average pulse width of the fuel injectors for
each bank of the engine as determined by the ECM.
B1/B2 S1 Heated O2 Sensor 1 (Bank 1 or Bank 2 Sensor 1): This parameter displays the lambda output from the
HEATED O2 SENSORS to the ECM. A lambda below 1.0 indicates a rich exhaust, while a lambda above 1.0 indicates a
lean exhaust.
B1/B2 S2 Heated O2 Sensor 2 (Bank 1 or Bank 2 Sensor 2): This parameter displays the mV output from the
HEATED O2 SENSORS to the ECM. A lower voltage indicates a lean exhaust, while a higher voltage indicates a rich
exhaust.
B1/B2 S1 Heated O2 Sensor Heater (Bank 1 or Bank 2 Sensor 1): This parameter displays the resistance of the
sensing element within the ECM. The front sensors are normally regulated to 80 ohms.
B1/B2 S1/S2 O2 Sensor Heater Circuit Status (Bank 1 or Bank 2 Sensor 1 or Sensor 2): The parameter displays
‘Fault’ if the oxygen sensor heater control circuit is open, shorted to ground, or shorted to voltage. The parameter
displays ‘Undefined’ until the circuit has been commanded ON.
Barometric Pressure: This parameter displays the barometric pressure in kPa. The ECM uses the barometric pressure
for fuel control to compensate for altitude differences.
Barometric Pressure: This parameter displays the barometric pressure voltage. The control module uses the barometric
pressure for fuel control to compensate for altitude differences.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–233
Page 6C4-2–233
Brake Lamp Switch: This parameter displays the serial data message of the brake signal from the antilock braking
system, control module (ABS). Regardless of the braking variant (ABS / ABS-TCS or ABS-TCS/ESP) fitted to a V8
engined vehicle, the brake lamp switch signal is sent by the ABS control module.
Brake Sw itch Signal Status: This parameter displays the position of the torque converter clutch (TCC) brake pedal
switch input to the ECM.
Calculated ECT – Closed Loop Fuel Control (Engine Coolant Temperature): This parameter displays the modelled
temperature that the control module calculates from air entering the engine, coolant temperature, and ambient air
temperature. If the actual engine coolant temperature does not reach this calculated temperature within a predetermined
amount of time, a DTC will set.
Calculated ECT – Thermostat Diagnosis (Engine Coolant Temperature): This parameter displays the modelled
temperature that the control module calculates from air entering the engine, coolant temperature, and ambient air
temperature. If the actual engine coolant temperature does not reach this calculated temperature within a predetermined
amount of time, a DTC will set.
Calculated Pedal Position: This parameter displays the angle of the accelerator pedal position (APP) as calculated by
the ECM, using the signals from the APP sensors, as a percentage of throttle opening.
Calculated Throttle Position: This parameter displays the percentage of throttle opening, based on the two TP sensor
inputs to the ECM.
Catalyst Protection Mode: This parameter displays if the control module is commanding catalytic converter protection
or not.
Catalyst Temperature (Bank 1 or Bank 2): This parameter displays the catalytic converter temperature as calculated by
the control module.
Clutch Pedal Sw itch: This parameter displays the state of the clutch pedal as determined by the ECM from the clutch
start switch position.
Clutch Pedal Sw itch: This parameter displays the state of the clutch pedal as determined by the ECM from the clutch
pedal switch.
Commanded B1/B2 S1 Heated O2 Sensor Heater (Bank 1 or Bank 2 Sensor 1): This parameter displays the state of
the oxygen sensor heater control circuit, as a percentage.
Commanded B1/B2 S1 O2 Sensor Value (Bank 1 or Bank 2 Sensor 1): T his parameter displays the lambda output
from the Heated O2 Sensors to the ECM. A lambda below 1.0 indicates a rich exhaust, while a lambda above 1.0
indicates a lean exhaust.
Coolant Temperature: This parameter displays the temperature of the engine coolant based on input to the control
module from the engine coolant temperature (ECT) sensor.
Crank Request: T his parameter displays whether the ignition switch has been cycled to the crank position, requesting
the ECM to activate the starter relay.
Cruise Control Active: This parameter displays the status of the cruise control system as determined by the ECM.
Cruise Control Switch: This parameter displays the state of the cruise control on/off switch input to the control module.
Cruise Control Disengagement Reason: The parameter displays which of a possible 28 causes for the cruise control to
disengage.
CC Disengagement 1 – 8 History (Cruise Contro l): The parameter displays the last 8 cruise control disengages in
order from 1 to 8, with 8 being the most recent. There are about 28 possible causes for the cruise control to disengage.
Cruise Resume/Acceleration Switch: This parameter displays the state of the cruise control resume/accel switch
position input to the ECM.
Cruise Set / Decel Switch: This parameter displays the state of the cruise controls set/decel. switch position input to the
ECM.
Cycles of Misfire: This parameter displays the number of misfire tests during 200 engine revolutions.
Cylinder 1 – 8 Injector Circuit Status: This parameter displays the state of the fuel injector control circuit. The
parameter displays ‘Fault’ if the fuel injector control circuit is open, shorted to ground, or shorted to voltage. This
parameter displays ‘Undefined Status’ until the control circuit has been commanded ‘On’.
Dec. Fuel Cut-off (Deceleration): This parameter displays the status of the ECM operating mode, used to turn off the
fuel injectors and the evaporative emission (EVAP) canister purge valve during certain deceleration conditions.
Desired Engine Idle Speed: This parameter displays the desired engine idle speed as commanded by the ECM.
Desired Throttle Position: This parameter displays the desired throttle position (TP) angle commanded by the ECM.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–234
Page 6C4-2–234
Distance Since DTC Cleared: This parameter displays the distance (km) travelled since any diagnostic trouble code
(DTC) has been cleared from the ECMs memory.
DTC Set This Ignition: This parameter displays Yes if a DTC set on the current ignition cycle.
ECM Immobilized: This parameter displays ‘Yes’ when an internal control module reset occurs. Tech 2 will display ‘No’
under normal operating conditions.
Engine Control Ignition Relay: This parameter displays the state of the control circuit for control module power relay as
commanded by the ECM.
Engine Control Igni tio n Relay Feedback: This parameter displays the voltage available at the engine control ignition
relay pin of the control module.
Engine Load: This parameter displays the calculated engine load in percent based on inputs to the control module from
various engine sensors.
Engine Oil Life Remaining: This parameter displays the percentage of engine oil life remaining. The controller
calculates the engine oil life by monitoring engine load, coolant temperature, and engine speed.
Engine Oil Pressure: This parameter displays the oil pressure in kPa from the ECM, developed from the engine oil
pressure (EOP) sensor input.
Engine Oil Pressure Sensor: This parameter displays ‘High’ if the engine oil pressure is within the correct range. If the
ECM detects that the engine oil pressure is not within the correct range, Tech 2 will display ‘Low’.
Engine Runtime: This parameter displays the time elapsed since the engine was started.
Engine Speed: This parameter displays the speed of the engine crankshaft rotation from information received from the
CKP sensor. If there is a CKP sensor DTC, the ECM calculates the engine speed from one of the camshaft position
(CMP) sensors.
EVAP Purge Solenoid (Evaporative Emission): This parameter displays the on-time or duty cycle of the EVAP canister
purge solenoid commanded by the ECM. Zero percent indicates no purge. One hundred percent indicates full purge.
EVAP Purge Solenoid Valve Circuit Status (Evaporative Emission): This parameter displays the state of the EVAP
purge solenoid control circuit. The parameter displays ‘Fault’ if the EVAP purge solenoid control circuit is open, shorted to
ground, or shorted to voltage. The parameter displays ‘Undefined Status’ until the circuit has been established as ‘OK’.
Extended Travel Brake Pedal Switch: This parameter displays the state of the brake pedal as determined by the ECM
from the extended travel brake pedal switch position.
Fan Relay 1: This parameter displays the control module commanded state of the fan relay control circuit.
Fan Relay 2 and 3: This parameter displays the control module commanded state of the fan relay control circuit.
Fan Relay 1 Circuit Status: This parameter displays the state of the fan relay control circuit. The parameter displays
‘Fault’ if the fan relay control circuit is open, shorted to ground, or shorted to voltage. The parameter displays ‘Undefined’
until the relay control circuit has been determined as being ‘OK’.
Fan Relay 2 and 3 Circuit Status: This parameter displays the state of the fan relay control circuit. The parameter
displays ‘Fault’ if the fan relay control circuit is open, shorted to ground, or shorted to voltage. The parameter displays
‘Undefined’ until the relay control circuit has been determined as being ‘OK’.
Fuel Level: This parameter displays the amount of fuel in the fuel tank in litres, as calculated by the ECM from data
received from the fuel level sensor.
Fuel Level Sensor: This parameter displays the voltage received from the fuel level sensor in the fuel tank, by the ECM.
Fuel Pump Relay Circuit Status: This parameter displays the state of the fuel pump relay control circuit. The parameter
displays ‘Fault’ if the fuel pump relay control circuit is open, shorted to ground, or shorted to voltage. The parameter
displays ‘Undefined’ until the relay control circuit has been determined as being ‘OK’.
Fuel Pump Relay: This parameter displays the ECMs commanded state of the fuel pump relay control circuit.
Fuel Trim Learn: This parameter displays ‘Enabled’ when conditions are appropriate for enabling long term fuel trim
corrections. This indicates that the long term fuel trim is adapting continuing amounts of short term fuel trim. If Tech 2
displays ‘Disabled’, then long term fuel trim will not respond to changes in short term fuel trim.
Ignition Accessory Signal: This parameter displays ‘On’ when the control module detects a voltage at the ignition ‘ACC’
terminal, X1-4 of the ignition switch.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–235
Page 6C4-2–235
Ignition On Signal: This parameter displays ‘On’ when the control module detects a voltage at the ignition ‘IGN’ terminal
X1-3 of the ignition switch.
Initial Brake Apply Signal: This parameter displays the serial data message of the brake signal from the antilock
braking system, control module (ABS). Regardless of the braking variant (ABS / ABS-TCS or ABS-TCS/ESP) fitted to a
V8 engined vehicle, the brake lamp switch signal is sent by the ABS control module.
Injection Time Cylinder 1 – 8: T his parameter displays the amount of fuel injector On-time or pulse width as
commanded by the ECM.
Intake Air Temperature: This parameter displays the temperature of the air entering the air induction system based on
input to the ECM from the intake air temperature (IAT) sensor.
Knock Sensor Signal (Bank 1 or Bank 2): These parameters display the voltage input to the control module from the
knock sensor (KS).
Knock Retard: T his parameter indicates the amount of spark advance in crankshaft degrees, that the ECM removes
from the ignition control (IC) spark advance in response to the signal from the knock sensors.
Knock Retard Cylinder 1 – 6: T his parameter displays the knock retard as commanded by the ECM for cylinders 1-8.
Each cylinder is controlled individually based on both knock sensor signal inputs.
Loop Status B1S1 / B2S1 (Bank 1 or Bank 2 Sensor 1): This parameter displays the state of the fuel control system as
commanded by the ECM. ‘Closed’ Loop operation indicates that the ECM is controlling the fuel delivery based on the
oxygen sensors input signal. In ‘Open’ Loop operation the ECM ignores the oxygen sensor input signal and bases the
amount of fuel to be delivered on other sensor inputs.
LTFT Idle/Deceleration (Bank 1 or Bank 2) (Long Term Fuel Trim): This parameter displays the commanded Long
Term Fuel Trim correction by the ECM for bank 1 or bank 2 for idle and deceleration conditions.
LTFT Cruise/Acceleration (Bank 1 or Bank 2) (Long Term Fuel Trim): This parameter displays the commanded Long
Term Fuel Trim correction by the ECM for bank 1 or bank 2 for cruise and acceleration conditions.
Malfunction Indicator Lamp (MIL): This parameter displays the commanded (‘On, ‘Off’ or ‘Flashing’) state of the
malfunction indicator lamp (MIL) control circuit by the ECM.
Malfunction Indicator Lamp (MIL) Circuit Status: This parameter displays the state of the MIL control circuit. The
parameter displays ‘Fault’ if the MIL control circuit is open, shorted to ground, or shorted to voltage. This parameter
displays ‘Undefined Status’ until the circuit has been determined as being ‘OK’.
Mass Air Flow: This parameter displays the measured quantity (g/s) of air flowing into the engine during all operating
conditions.
Mass Air Flow Sensor: This parameter displays the signal voltage from the mass air flow (MAF) sensor to the ECM.
Misfire Current Cyl. #1 – #8: Tech 2 displays a range of 0 – 200 counts. This parameter displays the number of misfires
that have been detected during the last 200 cylinder firing events. The counters may normally display some activity, but
the activity should be nearly equal for all of the cylinders, and in low numbers.
Misfire History Cyl. #1 – #8: Tech 2 displays a range of 0 – 65,535 counts. The misfire history counters display the total
level of misfire that has been detected on each cylinder. The misfire history counters will not update or show any activity
until a misfire DTC P0300 has become active. The misfire history counters will update every 200 cylinder firing events.
Oil Level: When the ECM receives information from the engine oil level switch, where the engine oil level is within preset
parameters, Tech 2 will display ‘Normal’. If not within preset parameters, the display will show ‘Low’.
Oil Temperature Sensor: This parameter displays the engine oil temperature in degrees C.
Pow er Enrichment: This parameter displays the status of the operating mode of the ECM used to increase fuel delivery
during certain acceleration conditions.
Reduced Engine Power: This parameter displays when the ECM is commanding reduced engine power due to a throttle
actuator control (TAC) system condition.
Requested Torque: This parameter displays the calculated amount torque requested of the ECM by the Transmission
Control Module (TCM).
Short Term Fuel Trim (Bank 1 or Bank 2): This parameter displays the short-term correction to the fuel delivery by the
ECM in response to oxygen sensor 1 or 2. If the oxygen sensor indicates a lean air/fuel mixture, the control module will
add fuel, increasing the short term fuel trim above 0. If the oxygen sensor indicates a rich air/fuel mixture, the control
module will reduce fuel decreasing the short term fuel trim below 0.
Spark Advance: This parameter displays the amount of spark advance the ECM is commanding on the ignition control
circuits. The ECM determines the desired advance.
Starter Relay: This parameter displays the ECMs commanded state of the starter motor relay control circuit.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–236
Page 6C4-2–236
Starter Relay Circuit Status: This parameter displays the state of the starter relay control circuit. The parameter
displays ‘Fault’ if the starter relay control circuit is open, shorted to ground, or shorted to voltage. The parameter displays
Undefined Status’ until the circuit has been determined as being ‘OK’. This parameter may not change if Tech 2 is used
to command the relay control circuit ON.
Start Up ECT (Engine Coolant Temperature): This parameter displays the temperature of the engine coolant on start
up based on input to the ECM from the ECT sensor.
Start Up IAT (Intake Air Temperature): This parameter displays the temperature of the intake air at start in the air
induction system based on input to the ECM from the IAT sensor.
Time Since Engine Off: This parameter displays the amount of time (hours:minutes:seconds) that has elapsed since the
engine was last cycled OF F.
Total Fuel Trim (Bank 1 or Bank 2): This parameter displays the overall fuel trim from the idle/decel cell and the
cruise/accel cell.
Total Misfire: This parameter displays the total number of cylinder firing events that the control module detected as
misfires for the last 200 crankshaft revolution sample period.
TP Sensor 1 (Throttle Position): This parameter displays the actual voltage on the TP sensor 1 signal circuit as
measured by the ECM.
TP Sensor 1 Learned Low er Position (Throttle Position): This parameter displays the learned minimum value of TP
sensor 1 as recorded by the ECM during the last learn procedure.
TP Sensor 2 (Throttle Position): This parameter displays the actual voltage on the TP sensor 2 signal circuit as
measured by the ECM.
TP Sensor 2 Learned Low er Position (Throttle Position): This parameter displays the learned minimum value of TP
sensor 2 as recorded by the ECM during the last learn procedure.
TP Sensor 1-2 Correlation (Throttle Position): This parameter displays ‘Fault’ when the ECM detects that T P sensor 1
voltage signal is not within the correct relationship to TP sensor 2. Tech 2 displays ‘Okay’ under normal operating
conditions.
Traction Control: This parameter displays ‘Active’ if the ABS / TCS module is commanding traction control.
Transmission Gear: T his parameter displays the position of the transmission gear selector that is transmitted over the
serial data circuit from the TCM.
Transmission Gear Selector Signal: This parameter displays the position of the transmission gear selector that is
transmitted over the serial data circuit from the TCM.
Vehicle Speed: T his parameter displays the speed of the vehicle as calculated by the TCM from information received
from the vehicle speed sensor (VSS).
Volumetric Efficiency: This parameter displays the volumetric efficiency of the engine as calculated by the control
module.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–237
Page 6C4-2–237
7.5 OBD Data
Typical Values
Tech 2 Display Units Displayed Ignition On Engine Running
B1S1 Heated O2 Sensor (Bank 1 Sensor 1) MA 0.008 0
B1S1 Short Term Fuel Trim (Bank 1 Sensor 1) % 99.2 99.2
B1S2 Heated O2 Sensor (Bank 1 Sensor 2) MV 440 445
B1S2 Short Term Fuel Trim (Bank 1 Sensor 2) % 99.2% 99.2%
B2S1 Heated O2 Sensor (Bank 2 Sensor 1) MA 0.000 0.024
B2S1 Short Term Fuel Trim (Bank 2 Sensor 1) % 99.2 99.2
B2S2 Heated O2 Sensor (Bank 2 Sensor 2) MV 440 475
B2S2 Short Term Fuel Trim (Bank 2 Sensor 2) % 99.2 99.2
Fuel System 1 Automatic Control Loop — — —
Fuel System 2 Automatic Control Loop — — —
Calculated Load % 100.0 18.8
Engine Coolant Temperature °C 56 90
B1 Short Term Fuel Trim (Bank 1) % 0.0 –0.8
B1 Long Term Fuel Trim (Bank 1) % 0.0 0.0
B2 Short Term Fuel Trim (Bank 2) % 0.0 0.8
B2 Long Term Fuel Trim (Bank 2) % 0.0 0.0
Engine Speed RPM 0 588
Vehicle Speed km/h 0 0
Ignition Timing Advance for Cylinder 1 °CA 0 13
Intake Air Temperature °C 47 32
Mass Air Flow g/s 0.00 2.75
Absolute TP (Throttle Position) % 14.5
OBD Requirements to which Vehicle is Designed EOBD — —
Distance While MIL is Activated Km 0 0
Commanded EVAP Purge (Evaporative Emissions) %
Fuel level %
Number of warm ups since DTC cleared
Distance Since DTC cleared Km
Barometric Pressure Kpa
B1S1 Catalyst Temperature °C
B2S1 Catalyst Temperature °C
Battery Voltage V
Absolute Load %
Commanded Lambda Value
Relative Throttle Position %
Ambient Temperature °C
Absolute TP B (Throttle Position) %
APP D (Accelerator Pedal Position) %
APP E (Accelerator Pedal Position) %
Commanded Throttle Actuator Control %
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–238
Page 6C4-2–238
7.6 Actuator Test
Fan Relays
Take care that no-one can access the engine
compartment during these tests!
F0: Fan Relay 1: This test allows the Technician to turn fan relay 1, on and off.
F1: Fan Relays 2 and 3: This test allows the Technician to turn fan relays 2 and 3, on and off.
F2 Fan Relays 1, 2 and 3: This test allows the Technician to turn fan relays 1, 2 and 3, on and off.
Preconditions (All Tests): Air conditioning is ‘Off’.
NOTE
Three relays are only fitted to those vehicles with
the 430 Watt cooling fan package.
Fuel Pump Relay Test
This test allows the Technician to turn the fuel pump on and off.
NOTE
To avoid the possibility of engine flooding and
subsequent catalytic converter damage, Tech 2
will deactivate the fuel pump relay after 2
seconds.
Precondition: Ignition ‘On’, engine ‘Off’.
Electronic Throttle Control Test
This selection from the Tech 2 Actuator T est menu, provides two parameters; the Calculated Throttle Position and the
Desired Throttle Position. As the Technician increases or decreases the throttle opening in 10% increments, each of the
two parameters should be the same.
Preconditions: Ignition ‘On’, engine ‘Off’, vehicle speed is 0 km/h, there are no vehicle speed DTCs set and the ECM is
not performing a throttle learn procedure.
A/C Relay Test
Allows the Technician to turn the air conditioning relay ‘On’ and ‘Off’.
Precondition: Ignition ‘On’.
Alternator L Terminal
This test allows the Technician to turn ‘On’ and ‘Off’, the commanded state of the voltage regulator in the alternator. ‘On’
displays a commanded state of 99%, while ‘Off’ displays a commanded state of 0%.
Precondition: Engine running.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–239
Page 6C4-2–239
EVAP Purge Solenoid
This test allows the Technician to control the EVAP purge solenoid valve. The normal commanded state is ‘0%’. The
system will increase or decrease the amount of purge by changing the duty cycle of the purge valve in 10% increments
within a range of 0 – 100%. The system will remain in the commanded state until cancelled by Tech 2.
NOTE
The EVAP Purge Solenoid Command parameter
may not change states when using this output
control.
Precondition: Ignition ‘On’, engine ‘Off’.
Engine Speed Control
Other DTCs may set when the Engine Speed
Control function is used. Disregard those
DTCs that set under this condition.
Allows the increase / decrease of the engine speed in 20 – 30 rpm increments from the base idle speed, up to 1,600 rpm.
NOTE
If the engine coolant temperature is below the
prescribed minimum, a message to that effect is
displayed and access to engine speed control is
blocked.
Preconditions: Engine running, engine temperature above 80°C, transmission in Park or Neutral.
Starter Motor Relay Test
The engine will crank and start during the
starter relay test.
Allows the Technician to turn the starter relay ‘On’, thereby activating the starter motor and cranking the engine.
Preconditions: Apply park brake, firmly apply foot brake, ignition ‘On’, engine ‘Off’, transmission in Park or Neutral.
Malfunction Indicator Lamp (MIL) Test
Selecting this parameter from the Tech 2 Actuator Test menu, allows the Malfunction Indicator (MI) icon in the
Instrument, to be activated, deactivated or commanded to flash. The object is to check the circuitry integrity from the
ALDL to the Instrument
Preconditions: Ignition ‘On’, engine ‘Off’, vehicle speed 0 km/h.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–240
Page 6C4-2–240
Fuel Injector Balance
This test allows the Technician to check the fuel flow through each injector when the engine is not running. The sequence
of events are:
1 Install a fuel pressure gauge to the fuel rail.
2 Select ‘Fuel Injector Balance Test’, from the ‘Actuator Test’ menu on Tech 2.
3 Activate the fuel injector balance test with Tech 2. This action activates the fuel pump and stabilises the fuel
delivery system fuel pressure. The fuel pump is then turned off.
4 Note the stabilised fuel rail pressure.
5 When the pump is turned ‘Off’, the injector is activated for a pre-determined time.
6 The fuel pressure drop is then noted from the fuel pressure gauge.
NOTE
For a detailed procedure and analysis of fuel
injector condition, refer to 5.3 Fuel Injector
Balance Test.
Engine Management GEN IV V8 – Diagnostics Page 6C4-2–241
Page 6C4-2–241
7.7 Programming
F0: BCM Link to ECM/PIM: Should the ECM, PIM or BCM be replaced, the modules must be security linked to
each other. If this linking procedure is not performed, the vehicle will not crank nor run. For additional
information relating to Tech 2 and the linking procedure, refer to Section 12J Body Control Module.
NOTE
After an ECU reset, the ignition switch must be
turned Off for at least 10 seconds and then turned
On for at least one minute, before attempting
communication between Tech 2 and the ECU.
Preconditions: TIS approval (TIS 2000 Security Access) must be obtained, the four digit security number
entered into Tech 2 and the theft deterrent system disarmed. Then the ignition must be turned ‘On’, using a
programmed remote coded key.
F1: Reset ECM: This function erases the security link between the Engine Control Module (ECM) and the
Powertrain Interface Modules (PIM). If this procedure is performed, the engine will not crank nor run. A BCM
Link to ECM/PIM procedure will need to be performed. For additional information relating to the BCM Link to
ECM/PIM procedure, refer to Section 12J Body Control Module.
NOTE
After an ECM reset, the ignition switch must be
turned Off for at least 10 seconds and then turned
On for at least one minute, before attempting
communication between Tech 2 and the ECM.
Preconditions: The four digit security code must be entered into Tech 2 and the theft deterrent system must
be disarmed and the ignition switched ‘On’ with a programmed remote coded key.
F2: Fuel Trim Reset: This function resets the fuel trim data values learned by the ECM.
F3: Reset Engine Oil Life: This function resets the engine oil life parameters into the ECM, following an engine
oil change.
F4: Throttle Body Relearn: In this mode, Tech 2 commands the throttle plate from its rest position to fully closed
then to about 10% open. This procedure takes approximately 6 – 8 seconds. At the start of this procedure, the
Tech 2, ‘Electronic Throttle Control Learn Counter’ parameter should display ‘0’ then count up to 11, after the
procedure is completed. If the counter does not start at ‘0’, nor display a count of ‘11’ at the conclusion of the
procedure, a fault has occurred and a DTC will set.