Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 1

7E2 – 1

Section 7E2

Automatic Transmission – 5L40-E –

Electrical Diagnosis

ATTENTION

Before performing any Service Operation or other procedure described in this Section, refer to Section 00

Warnings, Cautions and Notes for correct workshop practices with regard to safety and/or property damage.

1 General Information ...............................................................................................................................4

1.1 General Description............................................................................................................................................... 4

Transmission Adaptive Functions ....................................................................................................................... 5

Safety Mode Description....................................................................................................................................... 5

1.2 Transmission Indicators and Messages.............................................................................................................. 6

MFD Displays ......................................................................................................................................................... 6

Shift Mode.......................................................................................................................................................... 6

Active Select Mode............................................................................................................................................. 6

Shift Range Selected.......................................................................................................................................... 7

1.3 Automatic Transmission Electrical Circuits........................................................................................................ 8

1.4 Electronic Component Description.................................................................................................................... 10

Transmission Control Module (TCM)................................................................................................................. 10

Transmission Manual Shift Shaft Switch Assembly......................................................................................... 11

Transmission Output Shaft Speed (OSS) Sensor............................................................................................. 12

Transmission Input Shaft Speed (ISS) Sensor.................................................................................................. 13

Transmission Fluid Temperature (TFT) Sensor ................................................................................................ 13

Shift Solenoid (SS) Valves .................................................................................................................................. 14

Torque Converter Clutch Pulse Width Modulated (TCC PWM) Solenoid Valve.............................................. 15

Pressure Control (PC) Solenoid Valve............................................................................................................... 16

Duty Cycle, Frequency and Current Flow......................................................................................................... 16

Transmission Adapt Function........................................................................................................................... 16

20 Way Wiring Harness Connector .................................................................................................................... 17

1.5 Automatic Transmission Wiring Harness Connectors..................................................................................... 18

In-Line 20-Way Connector End View.................................................................................................................. 18

Transmission Side – X121–X1......................................................................................................................... 18

Wiring Harness Side – X121–X1...................................................................................................................... 19

Internal Connector End Views............................................................................................................................ 20

Transmission Manual Shift Shaft Switch Assembly.......................................................................................... 20

1–2 Shift Solenoid (SS) Valve Connector......................................................................................................... 20

2–3 Shift Solenoid (SS) Valve Connector......................................................................................................... 20

4–5 Shift Solenoid (SS) Valve Connector......................................................................................................... 20

Pressure Control (PC) Solenoid Valve Connector............................................................................................ 21

Torque Converter Clutch (TCC) Pulse-Width M odulated (PWM) Solenoid Valve Connector........................... 21

Output Speed (OSS) Sensor Connector .......................................................................................................... 21

Input Speed (ISS) Sensor Connector............................................................................................................... 21

Automatic Transmission Related Connector End Views ................................................................................. 22

Stop Lamp, Torque Converter Clutch & Cruise Control Release Switch S220–X1 .......................................... 22

Transmission Control Module A112 – T68 Connector X1 ................................................................................ 22

1.6 Automatic Transmission Diagnostic Trouble Codes........................................................................................ 24

Diagnostic Trouble Code (DTC) Definitions ...................................................................................................... 24

Type A.............................................................................................................................................................. 24

Type B.............................................................................................................................................................. 24

Type C .............................................................................................................................................................. 24

Diagnostic Trouble Code (DTC) Listing............................................................................................................. 24

Techline

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 2

7E2 – 2

2 Automatic Transmission Diagnostic Information and Procedures.................................................26

2.1 Introduction.......................................................................................................................................................... 26

2.2 General Diagnostic Procedures.......................................................................................................................... 27

Diagnostic System Check – Vehicle................................................................................................................... 27

Symptoms Diagnostics ....................................................................................................................................... 27

Diagnostic Trouble Code (DTC) Tables ............................................................................................................. 27

Multiple DTCs Fault Condition............................................................................................................................ 27

2.3 Diagnostic System Check – Automatic Transmission (5L40-E) ...................................................................... 28

3 Tech 2 – Automatic Transmission......................................................................................................30

3.1 Introduction.......................................................................................................................................................... 30

3.2 Automatic Transmission Data Lists................................................................................................................... 31

Ignition ON....................................................................................................................................................... 31

Engine Running................................................................................................................................................ 31

F0: Transmission Data......................................................................................................................................... 31

F0: Transmission Data List Definitions ............................................................................................................. 32

F1: TCC Data......................................................................................................................................................... 35

F1: TCC Data List Definitions ........................................................................................................................... 36

F2: 1-2 Shift Data .................................................................................................................................................. 37

F2: 1-2 Shift Data List Definitions ..................................................................................................................... 38

F3: 2-3 Shift Data .................................................................................................................................................. 39

F3: 2-3 Shift Data List Definitions ..................................................................................................................... 39

F4: 3-4 Shift Data .................................................................................................................................................. 41

F4: 3-4 Shift Data List Definitions ..................................................................................................................... 41

F5: 4-5 Shift Data .................................................................................................................................................. 42

F5: 4-5 Shift Data List Definitions ..................................................................................................................... 43

F6: Pressure Control Solenoid Data ................................................................................................................... 44

F6: Pressure Control Solenoid Data List Definitions......................................................................................... 44

F7: Transmission Adapts..................................................................................................................................... 45

F0: 1-2 Adapt Data ........................................................................................................................................... 45

F1: 2-3 Adapt Data ........................................................................................................................................... 47

F2: 3-4 Adapt Data ........................................................................................................................................... 48

F3: 4-5 Adapt Data ........................................................................................................................................... 49

F4: Steady State Adapt Data............................................................................................................................ 50

F8: System Identification..................................................................................................................................... 52

3.3 Tech 2 – Output Controls.................................................................................................................................... 53

4 Automatic Transmission Diagnostic Trouble Code Charts.............................................................56

DTC P0115 – GMLAN Engine Coolant Temperature Fault (No valid GMLAN signal)..................................... 56

DTC P0120 – Throttle Position Signal (No valid GMLAN signal) ..................................................................... 58

DTC P0218 – Transmission Fluid Over-Temperature ....................................................................................... 60

DTC P0562 – System Voltage Low ..................................................................................................................... 64

DTC P0563 – System Voltage High..................................................................................................................... 67

DTC P0572 – Brake Switch ‘Stuck Off’............................................................................................................... 69

DTC P0573 – Brake Switch ‘Stuck On’............................................................................................................... 71

DTC P0601 – TCM ROM Test............................................................................................................................... 74

DTC P0602 – No Start Calibration....................................................................................................................... 76

DTC P0603 – Power-Up Copy of NVM to RAM................................................................................................... 78

DTC P0604 – RAM Test........................................................................................................................................ 80

DTC P0711 – Transmission Fluid Temperature Sensor Circuit – Performance Test ..................................... 82

DTC P0712 – Transmission Fluid Temperature Sensor Circuit – Low Input (High Temperature)................. 86

DTC P0713 – Transmission Fluid Temperature Sensor Circuit – High Input (Low Temperature)................. 88

DTC P0716 – Transmission Input Speed Sensor – Performance Signal Drop................................................ 90

DTC P0717 – Transmission Input Speed Sensor – Low Input, No Activity..................................................... 94

DTC P0722 – Transmission Output Speed Sensor – Low Input....................................................................... 98

DTC P0723 – Transmission Output Speed Sensor – Intermittent.................................................................. 102

DTC P0727 – Engine Speed Sensor Circuit – No Valid GMLAN Signal......................................................... 106

DTC P0741 – TCC System Stuck OFF .............................................................................................................. 108

DTC P0742 – TCC System Stuck ON................................................................................................................ 113

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 3

7E2 – 3

DTC P0748 – Pressure Control Solenoid Circuit Fault................................................................................... 118

DTC P0751 – 1–2 Shift Solenoid Stuck On ...................................................................................................... 122

DTC P0752 – 1–2 Shift Solenoid Stuck Off ...................................................................................................... 127

DTC P0756 – 2–3 Shift Solenoid Stuck Off ...................................................................................................... 132

DTC P0757 – 2–3 Shift Solenoid Stuck On ...................................................................................................... 137

DTC P0761 – 4–5 Shift Solenoid Stuck Off ...................................................................................................... 142

DTC P0762 – 4–5 Shift Solenoid Stuck On ...................................................................................................... 147

DTC P0815 – Transmission Upshift Switch Circuit Stuck On........................................................................ 152

DTC P0816 – Transmission Downshift Switch Circuit Stuck On................................................................... 156

DTC P0826 – Tap Circuit Reads An Invalid Voltage Range............................................................................ 160

DTC P0973 – 1–2 Shift Solenoid Electrical Fault (Open or Short to Ground)............................................... 164

DTC P0974 – 1–2 Shift Solenoid Electrical Fault (Short to Voltage).............................................................. 167

DTC P0976 – 2–3 Shift Solenoid Electrical Fault (Open or Short to Ground)............................................... 170

DTC P0977 – 2–3 Shift Solenoid Electrical Fault (Short to Voltage).............................................................. 173

DTC P0979 – 4–5 Shift Solenoid Electrical Fault (Open or Short to Ground)............................................... 176

DTC P0980 – 4–5 Shift Solenoid Electrical Fault (Short to Voltage).............................................................. 179

DTC P1621 – Power Down Copy Of RAM to NVM ........................................................................................... 182

DTC P1793 – Wheel Speed Sensor Signal – No Valid GMLAN Signal........................................................... 184

DTC P1815 – IMS Start In Wrong Range .......................................................................................................... 186

DTC P1820 – IMS Circuit A Low........................................................................................................................ 191

DTC P1822 – IMS Circuit B High....................................................................................................................... 194

DTC P1823 – IMS Circuit P Low........................................................................................................................ 197

DTC P1825 – IMS Illegal Range......................................................................................................................... 200

DTC P1826 – IMS Circuit C High....................................................................................................................... 204

DTC P1831 – High Side Driver 1 Short To Ground.......................................................................................... 207

DTC P1832 – High Side Driver 1 Short To Voltage.......................................................................................... 210

DTC P1833 – High Side Driver 2 Short To Ground.......................................................................................... 212

DTC P1834 – High Side Driver 2 Short To Voltage.......................................................................................... 214

DTC P2544 – Torque Reduction Signal Circuit – CAN.................................................................................... 216

DTC P2637 – Engine Torque Signal Circuit – No Valid GMLAN Signal......................................................... 218

DTC P2763 – TCC PWM Solenoid Fault – Short to Voltage............................................................................ 220

DTC P2764 – TCC PWM Solenoid Fault – Open or Short to Ground............................................................. 223

DTC U0100 – GMLAN Bus Error Betw een Engine ECU and TCM.................................................................. 227

5 Specifications.....................................................................................................................................230

6 Special Tools ......................................................................................................................................231

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 4

7E2 – 4

1 General Information

1.1 General Description

The Hydra-matic 5L40-E autom atic transmission incorporates electronic c ontrols that utilise a Transmission Control

Module (TCM) to control shift points (through the three shift solenoi d valves), Torque Converter Clutch (TCC) apply and

release (through the TCC Pulse W idth Modulated (PWM) solenoid) and line pressure (through the Pressure Control (PC)

solenoid valve). Electrical signals from various sensors provide the information to the TCM about vehicle speed, throttle

position, engine coolant temperature, transmission fluid temperature, gear range selector position, engine speed,

converter turbine speed, engine load braking and operating mode. The TCM uses this information to determine the

precise moment to upshift or downshift, apply or release the TCC and what fluid pressure is needed to apply the

clutches. This type of control provides consistent and precise shift points and shift quality based on the operating

conditions of the vehicle.

If for any reason the entire electronic control systems of the transmission becomes disabl ed, all three of the shift

solenoids will be de-energised (turned off). This ‘Safety Mode’ operating state of the solenoids forces the transmission to

operate in fifth gear regardless of the other vehicl e operating conditions when the gear selector is in a forward drive

range. Also in ‘Safety Mode’, the PC solenoid is turned off which causes an increase in line pressure to maximum and

the TCC PWM solenoid can not apply the TCC. This allows the vehicle to be operated safely, despite the electronic

controls being disabled, until the condition can be corrected.

The electronic components of the 5L40–E automatic transmission are as shown next:

Figure 7E2 – 1

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 5

7E2 – 5

Legend

42 Output Speed Sensor (OSS) 368 4–5 Shift Solenoid

44 Input Speed Sensor (ISS) 369 2–3 Shift Solenoid

55 Transmission Fluid Temperature (TFT) Sensor 376 1–2 Shift Solenoid

352 Torque Converter Clutch (TCC) Pulse Width Modulated

(PWM) Solenoid Valve 602 Transmission manual shift shaft switch assembly. Tech 2

refers to as an Internal Mode Switch (IMS)

357 Pressure Control (PC) Solenoid

• Internal Wiring Harness Assembly, with 20-way Wiring Harness Connector (located at right-hand rear of

transmission case.

• Transmission Control Module (TCM) – not shown.

Transmission Adaptive Functions

The Hydra-matic 5L40-E uses a line pressure control system which has the ability to adapt the system line pressure to

compensate for normal wear within the transmission, such as the clutch pack fibre plates, seals, springs, etc. The adapt

feature is similar in function to the long term/short term fuel trim feature of the engine management system.

The 5L40-E transmission uses the adapt function for ‘garage shifts’, upshifts and T orque Converter Clutch (TCC)

application. The TCM monitors the input shaft speed to determine if the shift is occurring too fast or too slow and adjusts

the pressure control solenoid to maintain the correct shift feel.

Safety Mode Description

If a major electrical system failure occurs which could affect vehicle safety or damage the transmission during norma l

operation, the TCM enters a safety mode. In this mode, the transmission operates in the following manner:

• The pressure control solenoid is off and the li ne pressure is at maximum to minimise clutch slippage.

• The TCC solenoid is off, therefore the torque converter clutch is disabled.

• All three of the shift solenoids are turned off. The transmission will operate in fifth gear if the vehicle has

successfully completed a 1–2 upshift in the current ignition cycle. If the vehicle has not completed a 1–2 upshift in

the current ignition cycle, the transmission will operate in fourth gear. If the transmission is operating in fifth gear,

fourth gear may be obtained if the engine is stopped briefly and re-started.

In safety mode, the gear selector lever is ineffective at selecting forward gear ranges. In fourth or fifth gear, heat builds

up in the transmission quickly, particularly in stop and go tra ffic. Excessive heat build-up may cause transmission failure

if the vehicle is driven for extended distances in safety mode.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 6

7E2 – 6

1.2 Transmission Indicators and Messages

While there are no telltale displays in the Instrument that relate to the operation of the 5L40-E automatic transmission,

the Multi Function Display (MFD) compo nent of the Instrument may display messages relating to this transmission.

MFD Displays

Shift Mode

By pressing the ‘PWR’ momentary contact switch in the centre console, the MFD displays ‘Power Shift’ (1) and the gear

symbol (2) will rotate for approximately 2 seconds. After this time, the display will revert to the icon ‘PWR’ (3) in the lower

left of the display. Refer to view ‘A’.

When the ‘PWR’ button is pre ssed again (view ‘B’), the MFD display will show the message ‘Normal Mode’ (1) and the

gear symbol will have a line through it (2). After approximately 2 seconds, the display and the ‘PWR’ icon will disappear.

Figure 7E2 – 2

Active Select Mode

When the Active Select mode of transmission shifting is selected by pressing the ‘A/S’ momentary contact switch in the

centre console, the MFD will display an icon of the steering wheel (2) and a message ‘Act ive Select Enabled’, (‘1’ in A),

for approximately 2 seconds. After this perio d, the letters ‘A/S’ (3) are displayed in the right side of the MFD displa y.

When the vehicle is moving, the driver may upshift by tapping the ‘+’ paddle on the right side of the horn bar or downshift

by tapping the ‘–‘ paddle on the left side of th e horn bar. Provided the driver command is wit hin th e TCM calibration, an

upshift/downshift will occur.

With a closed throttle coastdown, the TCM will automatically cause downshifts to occur, within the TCM calibratio n.

When the ‘A/S’ switch button is pressed again, the MFD will display the message ‘Active Select Off’, as shown in ‘B’,

again for approximately 2 seconds, after which time the message (1) and the steering wheel icon (2) are deactivate d.

Figure 7E2 – 3

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 7

7E2 – 7

Shift Range Selected

The automatic transmission range select position, is

displayed as a larg e icon (1) in the MFD for approximately

1 second, after which time the appropriate sector of the

smaller icons (2) will be displayed.

Figure 7E2 – 4

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 8

7E2 – 8

1.3 Automatic Transmission Electrical

Circuits

Figure 7E2 – 5 – Automatic Tran smission Electrical Circuits – 1 of 2

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 9

7E2 – 9

Figure 7E2 – 6 – Automatic Tran smission Electrical Circuits – 2 of 2

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 10

7E2 – 10

1.4 Electronic Component Description

Transmission Control Module (TCM)

The Transmission Control Mo dule (TCM) is located

behind the left side kick panel and connects directly to

the transmission wiring harness. A single 42-way

connector is used to make the connection b etween the

vehicle wiring and the T CM.

Figure 7E2 – 7

The TCM is an electronic control module that receives

input or provides output to control the operation of the

5L40-E automatic transmission.

The TCM receives the following inputs from the Engine

Control Module (ECM):

• Engine speed and torque values

• Engine Intake Air Temperature (IAT),

Accelerator Pedal Position (APP) information

• Engine Coolant Temperature (ECT)

• Kick-down request

• Traction control status

• Driver selected shift mode

• Air conditioning (A/C) status

The ECM provides this data to the TCM through the GM

Local Area Network (GMLAN).

Figure 7E2 – 8

The GMLAN is a 2-wire communic ation connection between the ECM, TCM, ABS/T C/ESP and PIM control modu les,

plus a connection to the Data Link C onnector (DLC).

Other TCM inputs are the following:

• Battery and ignition voltage

• Brake switch status

• Transmission manual shift sh aft switch assembly

• Transmission Fluid Temperature (TFT)

• Transmission Input (Shaft) Speed (ISS) sensor

• Transmission Output (Shaft) Speed (OSS) sensor

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 11

7E2 – 11

The TCM provides the following outputs to control the automatic transmission:

• Shift solenoids to control transmission shifting

• Torque Converter Clutch (T CC) Pulse Width Modulated (PWM) solenoid operation controls the apply and

release of the torque converter clutch assem bl y

• Pressure Control (PC) solenoi d which regulates transmission line pressure.

Other TCM outputs provided to the ECM / PIM are the following:

• Check Powertrain Malfunction Indicator Lamp (MIL) illumination request.

• Vehicle speed.

• Transmission input speed.

• Transmission fluid temperature.

• Commanded gear status.

• TCC status.

• Torque reduction requests.

• Manual shift shaft switch status.

Transmission Manual Shift Shaft Switch Assembly

The transmission manual shift shaft switch assembly (2)

is a sliding contact switch attached to the manual shift

shaft (1) and is located inside the transmissi on case.

For Tech 2 data and diagnostic purpos es, the manual

shift shaft switch assembly is referred to as the IMS

(Internal Mode Switch).

Figure 7E2 – 9

There are four inputs to the TCM from the transmission

manual shift shaft switch assembly which indi cate the

transmission gear selector lever position, with a fifth input

directed to the Engine Control Module (ECM). This

information is used for engine controls as well as

determining the transmission shift patterns.

The state of each input is available for display on the

Tech 2. The four input parameters represented are

Signal A, Signal B, Signal C and Signal P (Parity).

The fifth input (to the ECM) is Signal N (P/N Start).

Figure 7E2 – 10

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 12

7E2 – 12

Manual Shift Shaft Switch Assembly Logic

Gear Selector Position A B C P P/N

Park LOW HIGH HIGH LOW LOW

Park / Reverse LOW HIGH HIGH HIGH –

Reverse LOW LOW HIGH HIGH HIGH

Reverse / Neutral HIGH LOW HIGH HIGH –

Neutral HIGH LOW HIGH LOW LOW

Neutral / Drive 5 HIGH LOW LOW LOW –

Drive 5 HIGH LOW LOW HIGH HIGH

Drive 5 / Drive 4 LOW LOW LOW HIGH –

Drive 4 LOW LOW LOW LOW HIGH

Drive 4 / Drive 3 LOW HIGH LOW LOW –

Drive 3 LOW HIGH LOW HIGH HIGH

Drive 3 / Drive 2 HIGH HIGH LOW HIGH –

Drive 2 HIGH HIGH LOW LOW HIGH

Open HIGH HIGH HIGH HIGH –

Invalid HIGH HIGH HIGH LOW –

HIGH = Ignition Voltage LOW = 0 voltage

Transmission Output Shaft Speed (OSS) Sensor

The transmission Output (Shaft) Speed (OSS) sensor (1) is

a variable reluctance magnetic pickup located in the rear

underside of the transmission case. The sensor is mounted

inside the transmission case opposite the rear internal gear.

The rear internal gear is splined to the transmission output

shaft assembly.

Access to the OSS sensor is by removing the transmission

fluid pan and filter.

Physically, the OSS and the Input (Shaft) Speed (ISS)

sensor are identical.

Figure 7E2 – 11

The sensor consists of a permanent magne t surrounded

by a coil of wire. As the output shaft and rear internal

gear rotate, an alternating current (AC) is induced in the

coil by the 'teeth' on the rear internal gear as they pass

by the magnetic pickup. Therefore, whenever the vehicle

is moving, the OSS sensor produces an AC voltage

signal proportional to vehic le speed.

Figure 7E2 – 12

At the TCM, the AC signal is electronically converted to a 5 volt square wave pattern. The square wave pattern can then

be interpreted as transmission output speed by the TCM through the frequency of square waves in a given time frame.

The square waves can be thought of as a representation of the rear internal gear teeth. Therefore, the more teeth or

waves that pass by the magnetic pickup in a given time frame, the faster the vehicle is moving. The square wave pattern

is compared to a fixed clock signa l internal to the TCM to determine transmission output spee d.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 13

7E2 – 13

Transmission Input Shaft Speed (ISS) Sensor

The transmission Input (Shaft) Speed (ISS) sensor is

located in the front underside of the transmission case.

The ISS operates identically to the OSS sensor except

that is uses the stamped teeth on the reverse clutch input

housing assembl y as the rotor reluctor. The reverse

clutch input housing assembly is driv en at torque

converter turbine speed.

Figure 7E2 – 13

The ISS sensor square wave pattern is als o compared to

a fixed clock signal internal to the TCM to determine

actual converter turbine speed. T he T CM uses

transmission input and output speeds to help determine

line pressure, transmission shift patterns, TCC applied

pressure, gear ratios and T CC slippage for diagnostic

purposes.

Access to the ISS sensor is by removing the

transmission fluid pan and filt er.

Physically, the ISS and the Output (Shaft) Speed (OSS)

sensor are identical.

Figure 7E2 – 14

Transmission Fluid Temperature (TFT) Sensor

The TFT sensor is part of the transmission interna l wiring

harness assembly. The TFT sensor is a type of resistor,

known as a thermistor, which changes value based on

temperature. Refer to the following Transmission Fluid

Temperature (TFT) Sensor Specifications chart. The

sensor has a negative-temperature coeffici ent. This

means that as the temperature increases, the resistance

decreases and as the temperature decreas es the

resistance increases. The TCM supplies a 5-volt

reference signal to the sensor and measures the voltage

drop in the circuit. When the transmission fluid is cold the

sensor resistance is high and the TCM detects high

signal voltage. As the fluid temperature warms to a

normal operating temperature, the resistance becomes

less and the signal voltage decreases. The TCM uses

this information to maintain shift quality and torque

converter clutch application quality over operating

temperature range.

Figure 7E2 – 15

If transmission fluid temperatures become excessively high, above approximately 140°C, the TCM will disable the

Electronic Converter Clutch Control (ECCC) function a nd command lock up mode. Applying the TCC serves to reduce

transmission fluid temperatures created by the fluid coupling in the torque converter with the TCC released.

Above approximately 149°C, the TCM will set a transmission fluid temperature DT C (P0218). This causes the TCM to

use a fixed default val ue of 135°C as the transmission fluid temperature inp ut signal.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 14

7E2 – 14

TRANSMISSION FLUID TEMPERATURE (TFT) SENSOR SPECIFICATIONS

Temperature

(° C)

Minimum

Resistance

(Ohm)

Nominal

Resistance

(Ohm)

Maximum

Resistance

(Ohm)

-40°C 89 500 100 000 110 500

-30°C 46419 51 400 56 381

-20°C 25 120 27 610 30 100

-10°C 14 160 15 450 16 740

0°C 8278 8972 9666

10°C 5005 5391 5777

20°C 3120 3342 3564

30°C 2000 2132 2264

40°C 1317 1397 1477

50°C 888 938 988

60°C 613 645 677

70°C 432 453 474

80°C 310 324 338

90°C 228 237 246

100°C 170 176 182

110°C 128 132 136

120°C 98 101 104

130°C 77 79 81

140°C 60 62 64

150°C 48 49 50

Shift Solenoid (SS) Valves

The Hydra-matic 5L40-E uses three electromagnetic shift

solenoid (SS) valves 1–2, 2–3 and 4–5 to control upshifts

and downshifts in all for ward gear ran ges.

The shift solenoid valves are all id entical, normally

closed, 3-port, ON / OFF type solenoids controlled by the

TCM. These shift solenoid valves work together in a

combination of ON and OFF sequenc es to control the

various shift valves.

The TCM uses numerous inputs to determine which

solenoid state combination the transmission should be in.

Refer to the following Shift Solenoid Valv e State and

Gear Ratio chart for these combinations, noting that the

combination for the 1 – 2 and 3 – 4 shifts are the same.

Figure 7E2 – 16

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 15

7E2 – 15

Shift Solenoid Valve State and Gear Ratio

Gear Range 1–2 / 3-4 Shift Solenoid 2-3 Shift Solenoid 4-5 Shift Solenoid Gear Ratio

Park, Reverse, Neutral OFF ON OFF 3.16:1

First OFF ON OFF 3.45:1

Second ON ON OFF 2.21:1

Third ON OFF OFF 1.59:1

Fourth OFF OFF ON 1.00:1

Fifth OFF OFF OFF 0.76:1

• All shift solenoids are normally closed.

• The 4–5 shift solenoid also enables engine brakin g.

Shift solenoid valve resistance should measure between 15.0 – 17.0 Ohms when measured at 20°C. The resistance

should measure approximately 17.9 – 20.3 ohms at 158°C.

Torque Converter Clutch Pulse Width Modulated (TCC PWM) Solenoid Valve

The TCC PWM solenoid valve is a normally-closed pulse

width modulated (PWM) solenoid used to control the

apply and release of the converter clutch. The TCM

operates the solenoid with a negative duty cycle, at a

fixed frequency of 32 Hz, to control the rate of T CC

apply / release. The solenoid's ability to 'ramp' the TCC

apply and release pressures results in a smoother TCC

operation.

When vehicle operating conditions are appropri ate to

apply the TCC, the TCM increases the duty cycle to

allow the TCC PWM soleno id valve to command TCC

signal fluid pressure at a level sufficient to move the TCC

enable valve and the TCC control valve to the apply

position. Release pressure is directed to exh aust and

regulated apply fluid is directed to the apply side of the

converter pressure plate/damper assembly.

The TCM then increases the duty cycle to control a

slippage of 20 – 80 rpm between the pressure

plate/damper assembly and the converter cover.

Figure 7E2 – 17

This provides for improved absorption of eng ine vibrations and allows the TCC to appl y at low engine speeds in 2nd, 3rd,

4th and 5th gear. At high speed, lock up mode is set by activating the TCC PWM solenoid valve at maximum duty cycle.

Release of the TCC is achieve d b y decreasing the duty cycle to a level low enough to allow spring force to move the

TCC enable valve and the TCC control valve to the release position. Appl y fluid is directed to exhaust and converter feed

fluid is directed into the release circuit to the release side of the pressure plate / damper assembly.

There are also some operating conditions that may prevent or enab le TCC apply under various cond itions, engine

temperature, transmission temperature, or brake switch activation, depending on vehicle application.

TCC PWM solenoid valve resistance should measure between 10.0–11.5 ohms when measured at 20°C. The resistance

should measure approximately 11.8 – 13.6 ohms at 158° C.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 16

7E2 – 16

Pressure Control (PC) Solenoid Valve

The Pressure Control (PC) solenoid valve is a precision

electronic pressure regulator that controls transmission

line pressure based on curren t flow through its coil

windings. As current flow is increased, the magnetic field

produced by the coil moves the solenoi d' s plunger further

away from the exhaust port. Opening the exhaust port

decreases the output fluid pressure regulated by the PC

solenoid valve, which ultimately decreases line pressure.

The TCM controls the PC solenoid valve based on

various inputs including throttle position, tran smission

fluid temperature and gear state.

The pressure control solenoid valve resistance should

measure between 3.5 – 4.6 ohms when measured at

20°C. The resistance should measur e approximately

4.2 – 5.5 ohms at 158°C.

Duty Cycle, Frequency and Current Flo w

A duty cycle may be defined as the percent age of time

current is flowing through a sole noid coil during each

cycle. The number of cycles that occur within a specified

amount of time, usually measured in seconds, is called

'frequency'. Typically, the operation of an electronica lly

controlled pulse width modulated solenoid is explained in

terms of duty cycles and frequency.

Figure 7E2 – 18

The TCM controls the PC solenoid valve on a positive duty cycle at a fixed frequency of 292.5 Hz cycles per second. A

higher duty cycle provides a greater current flow through the solenoid. The high positive side of the PC solenoi d valve

electrical circuit at the TCM controls the PC solenoid valve operation. The TCM provides a ground path for the circuit,

monitors average current and continuously varies the PC solenoid valve duty cycle to maintain the correct average

current flowing through the PC solenoid valve.

The duty cycle and current flow to the PC solenoid valve are mainly affected by throttle position and engine torque. As

the throttle angle engine torque increases, the duty cycle is decreased b y the TCM which decreases current flow to the

PC solenoid valve. Current flow to the PC soleno id valve creates a magnetic field that moves the solenoid armature

against spring force.

Transmission Adapt Function

Programming within the TCM also allows for automatic adjustments in shift pressure that are based on the changing

characteristics of the transmission components. As the apply components within the transmission wear, the shift time

and the time required to apply a clutch, increases. To compensate for this wear, the TCM adjusts trim pressure by

controlling the PC solenoi d valve to maintain the originall y calibrated sh ift timing. The automatic adjusting process is

referred to as adaptive learnin g and it is used to ensure consistent shift feel plus increase transmission d urab ility. The

TCM monitors the Transmission Input Speed Sensor (TISS) and the Transmission Output Speed Sensor (TOSS) during

commanded shifts to determine if a shift is occurring too fast / slow or harsh / soft and adjusts the PC solenoi d valve

signal to maintain a set shift feel.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 17

7E2 – 17

20 Way Wiring Harness Connector

The transmission 20-way wiring harness connector is an

important part of the transmission operating system. Any

interference with the electrical conn ection can cause the

transmission to set Diagnostic Trouble Codes (DTC) or

affect proper operation.

The following items can affect the electrical conn ection:

• Bent terminals in the connector from rough

handling during connectio n and disconnection.

• Wires backing away from the pins or coming

uncrimped, in either the internal or the e xternal

wiring harness.

• Dirt or moisture contamination entering the

connector when disconnected.

• Pins in the internal wiring connector backing out of

the connector during connecti on.

• Transmission fluid leaki ng into the connector,

wicking up into the external wiring harness and

degrading the wire insulation.

Figure 7E2 – 19

• Low terminal tension in the external connector from excessive connection and disconnection of the wiring

connector assembly.

• Terminal corrosion from contamin ation.

• Damaged connector or connector lock assembly.

Remember the following points:

• To disconnect the connector, turn the connector clockwise and pull.

• Do not prise on the connector with a screwdriver or other too l.

• The connector should screw into place with a positive feel and lock when properly installed.

Whenever the vehicle external wiring connector is disconnected from the internal harness and the ignition is ON,

transmission DTCs will set. Clear these DTCs after reconn ecting to the transmission 20-way connector.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 18

7E2 – 18

1.5 Automatic Transmission Wiring Harness

Connectors

NOTE

Apart from the 20-Way wiring harness connector

to the automatic transmission, the remaining

electrical harness connectors are secured by a

latch that must be carefully lifted with either the

fingertips or a small bladed screwdriver before

disconnection.

In-Line 20-Way Connector End View

Transmission Side – X121–X1

Figure 7E2 – 20

Terminal / Pin Wire Colour Circuit No. Function

X1–1 OG 400 Output Speed (OSS) Sensor – High Si gnal

X1–2 BN 1786 Park / Neutral Signal

X1–3 WH 401 Output Speed (OSS) Sensor – Low Signal

X1–4 GN 451 Ground

X1–5 GY 898 4–5 Shift Solenoid Valve Co ntrol

X1–6 WH 2762 Transmission Fluid Temperature (TFT) Sensor Low Reference

X1–7 BK 772 Transmission Range Signal B

X1–8 WH 1229 Pressure Control (PC) Solenoid Valve H igh Control

X1–9 BU 1223 2–3 Shift Solenoid Valve Control

X1–10 RD 1227 Transmission Fluid Temperature (TFT) Sensor Signal

X1–11 GY 776 Transmission Range Signal Parit y

X1–12 — — Not Used

X1–13 GN 1228 Pressure Control (PC) Solenoid Valve High C ontrol

X1–14 BK 1222 1–2 Shift Solenoid Valve Control

X1–15 WH 1231 Input Speed (ISS) Sensor Low Signal

X1–16 RD 771 Transmission Range Signal A

X1–17 WH 1525 Solenoid Power Supply

X1–18 YE 1230 Input Speed (ISS) High Si gnal

X1–19 BU 773 Transmission Range Signal C

X1–20 YE 418 Torque Converter Clutch (TCC) PWM Solenoid Valve Cont rol

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 19

7E2 – 19

Wiring Harness Side – X121–X1

Figure 7E2 – 21

Terminal / Pin Wire Colour Circuit No. Function

X1–1 YE 400 Output Speed (OSS) Sensor – High Signal

X1–2 OG / BK 1786 Park / Neutral Signal

X1–3 PU 401 Output Speed (OSS) Sensor – Low Signal

X1–4 BK / WH 451 Ground

X1–5 PU 898 4–5 Shift Solenoid Valve Control

X1–6 BN / WH 2762 Transmission Fluid Temperature (TFT) Sensor Low Reference

X1–7 YE 772 Transmission Range Signal B

X1–8 L-BU / WH 1229 Pressure Control (PC) Solenoid Valve Low Control

X1–9 YE / BK 1223 2–3 Shift Solenoid Valve Control

X1–10 YE / BK 1227 Transmission Fluid Temperature (TFT ) Sensor Signal

X1–11 WH 776 Transmission Range Signa l Parity

X1–12 — — Not Used

X1–13 OG / BK 1228 Pressure Control (PC) Soleno id Valve High Control

X1–14 L-GN 1222 1–2 Shift Solenoid Valve Control

X1–15 BU / WH 1231 Input Speed (ISS) Sensor Low Signal

X1–16 BN / YE 771 Transmission Range Signal A

X1–17 OG 1525 Solenoid Power Supply

X1–18 OG / BK 1230 Input Speed (ISS) High Signal

X1–19 GY 773 Transmission Range Signal C

X1–20 BN 418 Torque Converter Clutch (TCC) PWM Solenoid Va lve Control

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 20

7E2 – 20

Internal Connector End Views

Transmission Manual Shift Shaft S witch

Assembly

Pin Wire

Colour Circuit

No. Function

A BN 1786 Park / Neutral Signal

B GY 776 TR P (Parity) Signal

C BK 772 TR Signal B

D RD 771 TR Signal A

E BU 773 TR Signal C

F GN 451 TR Ground

Figure 7E2 – 22

1–2 Shift Solenoid (SS) Valve Connec tor

Wire

Colour Circuit

No. Function

A BK 1222 1–2 SS Control

B WH 1525 Solenoid Power Supply

Figure 7E2 – 23

2–3 Shift Solenoid (SS) Valve Connec tor

Wire

Colour Circuit

No. Function

A BU 1223 2–3 SS Control

B WH 1525 Solenoid Power Supply

Figure 7E2 – 24

4–5 Shift Solenoid (SS) Valve Connec tor

Wire

Colour Circuit

No. Function

A GY 898 4–5 SS Control

B WH 1525 Solenoid Power Supply

Figure 7E2 – 25

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 21

7E2 – 21

Pressure Control (PC) Solenoid Valve

Connector

Wire

Colour Circuit

No. Function

A GN 1228 PC Solenoid High

Control

B WH 1229 PC Solenoid Low

Control

Figure 7E2 – 26

Torque Converter Clutch (TCC) Pulse-Width

Modulated (PWM) Solenoid Valve

Connector

Wire

Colour Circuit

No. Function

A YE 418 TCC PWM Control

B WH 1525 Solenoid Power Supply

Figure 7E2 – 27

Output Speed (OSS) Sensor Connector

Wire

Colour Circuit

No. Function

A OG 400 OSS High Signal

B WH 401 OSS Low Signal

Figure 7E2 – 28

Input Speed (ISS) Sensor Connector

Wire

Colour Circuit

No. Function

A YE 1230 ISS High Signal

B WH 1231 ISS Low Signal

Figure 7E2 – 29

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 22

7E2 – 22

Automatic Transmission Related Connector End Views

Stop Lamp, Torque Converter Clutch & Cruise

Control Release Switch S220–X1

Wire

Colour Circuit

No. Function

A OG / BU 640 Power from Stop Lamps

Fuse F5

B BU / RD 20 Switch Signal To TCM

Figure 7E2 – 30

Transmission Control Module A112 – T68

Connector X1

Figure 7E2 – 31

Terminal / Pin Wire Colour Circuit No. Function

X1–1 YE 400 Output Speed (OSS) Sensor – High Signal

X1–2 PU 401 Output Speed (OSS) Sensor – Low Signal

X1–3 OG / BK 1228 Pressure Control (PC) Solenoid Valve High Control (HSD1)

X1–4 BN 418 Torque Converter Clutch (TCC) PWM Solen oid Va lve Control

X1–5 BN / WH 4 Accessory Voltage

X1-6 BK / WH 451 Power Ground

X1–7 — — Not Used

X1–8 OG 1525 Solenoid Power Supply (HSD2)

X1–9 PK / BU 339 Ignition Voltage

X1–10 OG / BK 1230 Input Speed (ISS) Sensor Hi gh Signal

X1–11 BU / WH 1231 Input Speed (ISS) Sensor Low Signal

X1–12 — — Not Used

X1-13 PU 1319 Serial Data

X1–14 PU 5526 Steerin g Wheel Tap Up and Tap Down Switch Signal

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 23

7E2 – 23

Terminal / Pin Wire Colour Circuit No. Function

X1–15 YE / BK 1227 Tr ansmission Fluid Temperature (TFT) Sensor High Signal

X1–16 — — Not Used

X1–17 — — Not Used

X1–18 YE / BK 1223 2–3 Shift Solenoid Valve Control

X1–19 PU 898 4–5 Shift Solenoid Valve Control

X1–20 BN / BK 2500 High Speed GMLAN Serial Data Bus (CAN 2 High)

X1–21 BN 2501 High Speed GMLAN Serial Data Bus – (CAN 2 Low)

X1–22 — — Not Used

X1–23 — — Not Used

X1–24 YE 772 Transmission Ran ge Switch Signal B

X1–25 GY 773 Transmission Ran ge S witch Signal C

X1–26 BN / WH 2762 Transmission Fluid Temperature (TFT) Sensor Low Reference

X1–27 OG / BK 740 Battery Positive Voltage

X1–28 — — Not Used

X1–29 L-BU / WH 1229 Pressure Control (PC) Solenoid Valve Low Control

X1–30 L-GN 1222 1–2 Shift Solenoid Valve Control

X1–31 — — Not Used

X1–32 BN / BK 2500 High Speed GMLAN Serial Data Bus (CAN 1 High)

X1–33 BN 2501 High Speed GMLAN Serial Data Bus - (CAN 1 Lo w)

X1–34 — — Not Used

X1–35 — — Not Used

X1–36 BN / YE 771 Transmission Range Switch Signal A

X1-37 — — Not Used

X1-39 L-BU 20 Stop Lamp Signal – Switch S220 X1

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 24

7E2 – 24

1.6 Automatic Transmission Diagnostic

Trouble Codes

Diagnostic Trouble Code (DTC) Definitions

Diagnostic Trouble Cod es (DTCs) are grouped into several types. Each type has a unique set of characteristics for the

Malfunction Indicator Lamp (MIL) operation, DTC storage and DTC clearing. The following list contains a brief summary

of the DTC types and the associated propert ies of each.

Typ e A

This DTC is emissions related. The MIL illuminates and default actions, if any, are activated immediately after a failure is

detected. The DTC is then stored in histor y and the Freeze Frame data is captured.

Typ e B

This DTC is emissions related. Default actions, if any, are activated and a Failure Record is stored after the first failure is

detected. At the time of the first failure, the DTC will appear in memory as pending. If the next trip reports a pass, the

pending DTC is deleted. If the failure reoccurs on the ne xt consecutive drive cycle, the MIL illuminates, the DTC is stored

in history and the Freeze Fr ame data is captured at the time of failure.

Typ e C

This DTC is non emission related and does not turn on the MIL. When a Type C DTC sets, a message may be displayed

in the instrument cluster multi-function display.

Diagnostic Trouble Code (DTC) Listing

The following chart lists the Diagnostic Trouble Codes for the Hydra-matic 5L40-E transmission.

DTC Description DTC Type Illuminate MIL

P0115 GMLAN Engine Coolant Temperature Fault (No Valid GM LAN Signal) C No

P0120 Throttle Position Sign al (No Valid GM LAN Signal) B Yes

P0218 Tr ansmission Fluid Over Temperature C No

P0562 System Voltage Low C No

P0563 System Voltage High C No

P0572 Brake S witch ‘Stuck Off’ C No

P0573 Brake S witch ‘Stuck On’ C No

P0601 TCM ROM Test A Yes

P0602 No Start Calibration A Yes

P0603 Power–up Copy of NVM to RAM A Yes

P0604 RAM Test B Yes

P0711 Tr ansmission Fluid Temperature Sensor Circuit – Performance Test C No

P0712 Tr ansmission Fluid Temperature Sensor Circuit – Low Input (High Temp) C No

P0713 Tr ansmission Fluid Temperature Sensor Circuit – High Input (Lo w Temp) C No

P0716 Tr ansmission Input Speed Sensor – Performance Signal Drop B Yes

P0717 Transmission Input Speed Sensor – Low Input, No Activity B Yes

P0722 Tr ansmission Output Speed Sensor – Low Input B Yes

P0723 Transmission Output Speed Sensor – Intermittent B Yes

P0727 Engine Speed Sensor Circuit – No Valid GMLAN Signal B Yes

P0741 TCC System Stuck OFF B Yes

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 25

7E2 – 25

DTC Description DTC Type Illuminate MIL

P0742 TCC System Stuck ON B Yes

P0748 Pressure Contr ol Solenoid Circuit Fault C No

P0751 1–2 Shift Solenoid Stuck On B Yes

P0752 1–2 Shift Solenoid Stuck Off B Yes

P0756 2–3 Shift Solenoid Stuck Off B Yes

P0757 2–3 Shift Solenoid Stuck On B Yes

P0761 4–5 Shift Solenoid Stuck Off B Yes

P0762 4–5 Shift Solenoid Stuck On B Yes

P0815 Transmission Upshift Switch Circuit Stuck On C No

P0816 Transmission Downshift Switch Circuit Stuck On C No

P0826 Tap Circuit Reads An Invalid Voltage Range C No

P0973 1–2 Shift Solenoid El ectrical Fault (Open or Short to Ground) B Yes

P0974 1–2 Shift Solenoid Electrical Fault (Short to Voltage) B Yes

P0976 2–3 Shift Solenoid El ectrical Fault (Open or Short to Ground) B Yes

P0977 2–3 Shift Solenoid Electrical Fault (Short to Voltage) B Yes

P0979 4–5 Shift Solenoid El ectrical Fault (Open or Short to Ground) B Yes

P0980 4–5 Shift Solenoid Electrical Fault (Short to Voltage) B Yes

P1621 Power Down Copy of RAM to NVM A Yes

P1793 Wheel Speed Sensor Signal – No Valid GMLAN Signal C No

P1815 IMS Start In Wrong Range B Yes

P1820 IMS Circuit A Low B Yes

P1822 IMS Circuit B High B Yes

P1823 IMS Circuit P Low B Yes

P1825 IMS Illegal Range B Yes

P1826 IMS Circuit C High B Yes

P1831 High Side Driver 1 Short To Ground C No

P1832 High Side Driver 1 Short to Voltage C No

P1833 High Side Driver 2 Short To Ground B Yes

P1834 High Side Driver 2 Short to Voltage B Yes

P2544 Torque Reduction Signal Circuit – CAN B Yes

P2637 Engine Torque Signal Circuit – No Valid GMLAN Signal B Yes

P2763 TCC PWM Solenoid Fault – Short to Voltage B Yes

P2764 TCC PWM Solenoid Fault – Open or Short to Ground B Yes

U0100 GMLAN Bus Error Between Engine ECM and TCM B Yes

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 26

7E2 – 26

2 Automatic Transmission

Diagnostic Information and

Procedures

2.1 Introduction

As with any electronic system in a MY 2005

VZ/WL Series vehicle, the Diagnostic System

Check – Vehicle must be completed before

any other diagnostic procedure is carried out.

During the course of completing the

Diagnostic System Check – Vehicle, a number

of statements are made, reg ard ing preliminar y

checks. These must al so be referr ed to before

undertaking any diagnostic procedure. Refer

to Section 0D Vehicle Diagnostics for

information on;

2.1 Basic Knowledge Required

2.2 Basic Diagnostic Tools Required

2.3 Diagnostic Precautions

2.4 Preliminary Checks

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 27

7E2 – 27

2.2 General Diagnostic Procedures

Diagnostic System Check – Vehicle

All vehicle diagnostic procedures are organised in a log ica l structure that begins with the Diagnostic System Check –

Vehicle, refer to Section 0D Vehicle Diagnostics. The Diagnostic System Check – Vehicle must always be referred to

first, as you will be directed through the logical steps necessary to diagnose any vehicl e electrical fault condition.

Vehicle system diagnostic tables locate a faulty circuit or component through a logic al approach, based on a 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.

An understanding of and the correct use of the diagnostic tables is essential if the diagnostic time is to be minimis ed

and/or to prevent poor diagnosis.

Symptoms Diagnostics

Provided all of the following conditions exist, refer to the Symptoms Tables, in Section 7E3 Automatic Transmission –

5L40-E – Hydraulic/Mecha nical Diagnosis:

• An automatic transmission fault condition exists,

• There is no Current Diagnostic T r ouble Code presently stored in the ECM, and

• All the Tech 2 automatic transmission data parameters are within the normal operating range.

Diagnostic Trouble Code (DTC) Tables

Through the process of completing the Automatic Transmission Diagnostic Circuit Check, you will be directed to the

Diagnostic Trouble Cod e (DTC) Tables if there is a DTC currently stored in the Transmission Control Module (TCM).

Multiple DTCs Fault Condition

In any given electronic system, some fault conditions trigger multiple component DTCs even if the fault condition exists

only in a single component. If there are multiple DTCs stored in the TCM, the Technician must view and record all DTCs

logged.

The relationship between the logged DTCs can then be reviewed to determine the sourc e of the fault condition. Always

begin the diagnostic process by compl eting the Diagnostic Tabl e for the fault condition that may trigger other DTCs to

set.

The following fault conditions ma y trigger multiple DTCs:

• A system voltage that is too low may cause incorrect automatic transmission system management operation or a

component to malfunction.

• A system voltage that is too high may damage the TCM and/or other sensitive automatic transmission components.

• A fault condition in the TCM Read Only Memory (ROM) or Random Access Memory (RAM).

• A fault condition in the TCM internal circuitry or programming.

• An improperly connected sen sor or component wiring harness connector.

• An electrical fault condition in shared TCM electrical circuits may trigger DTCs for components or sensors that are

connected to the same faulty circuit (e.g. open in one of the GMLAN circuits). Test the electrical circuit of the

appropriate sensors or components to isolate the fault condition. Refer to Figure 6C2 – 2 and Figure 6C2 – 3 for

electrical circuit diagrams.

If there are no obvious faults to begin a multiple set DTC fault condition, always start with the lowest number, then work

progressively through each.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 28

7E2 – 28

2.3 Diagnostic System Check – Automatic

Transmission (5L40-E)

NOTE

Do not perform the Diagnostic System Check –

Automatic Transmission unless one of the

concerns noted is present. Failure to follow this

procedure could lead to misdiagnosis of the

system.

Description

The Diagnostic System Check – Automatic Transmission is an organised approach to identifying a condition identified by

the transmission electronic control system.

When an emission related DTC (type B) sets because of an automatic transmission fault, the TCM requests the Engine

Control Module (ECM) to activate the instrument cluster Check Powertrain Malfunction Indicator Lamp (MIL). The ECM

may also independently activate the MIL. Although either module may cause the MIL to activate, Tech 2 can display

DTCs from only one module at a time. However, the ‘Clear DTC Info’ command clears DTC data from both modules. If

the DTC failure records are not recorded from both modules before the DTC data is cleared, important diagnostic

information will be erased.

Your training and experience as a Technician may cause you to focus on either the TCM or the ECM, instead of both

modules at the same time. To ensure that both modul es are properly diagnosed, separate system checks are included.

The process detailed in the Diagnostic System Check – Vehicle identifies whether ECM related DTCs are recorded. If no

ECM DTCs are present, you will then be directed to this, Diagnostic System Check – Automatic T ransmission.

The ECM diagnostics do not require automatic transmission data to run. Correct use of the tables will reduce d iagnostic

time and prevent the replacement of good parts.

Diagnostic Aids

Inspect all of the related wiring and connections including those at the TCM, as these may cause an intermittent

condition. Inspect the terminals for any damage or a ny corrosion. Inspect the connector for any pushed-out terminals.

Test Description

The following number(s) refer to the step number(s) on the diagnostic table.

1 Do not perform the Diagnostic S ystem Check – Automatic Transmission unless the Diagnostic System Check –

Vehicle, refer Section 0D Vehicle Diagnostics is completed first. Failure to follow this procedure could lead to

misdiagnosis of the system.

2 Checks that Tech 2 powers up and that communication can be established with the Transmission Control Module

(TCM).

3 Check for any applicable Service Techlines before proceeding with the di agnosis.

4 If multiple automatic transmission DTCs are stored, diagnose the DTCs in numerical order, starting with the lowest

DTC number. When there is a known exception, a DTC table however, may direct you to diagnose a different DTC

first.

5 Compare the actual control system data with the values in the Transmission Tech 2 Data List in this Section, to

determine if any parameter is not within limits. A base engine condition, such as advanced cam timing, may

substantially alter the sensor values. If the actual data does not correspo nd with the values in the Tech 2

Transmission Data List, but the correspo nding DTC is not set, this indicates that some specific conditions have not

been met before some diagno stics will run. This information is in the supporting text for the DTC table. If you

suspect a system fault, such as Shift Solenoid operation, TCC operation, refer to the DTCs that apply to that

system. The DTC tables are not, by design, for use unless a DTC is set; however, many tables begin with a

functional test of the related component. This information can be a useful aid in diagnosis.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 29

7E2 – 29

Diagnostic System Check – Automatic Transmission

Step Action Yes No

1 Is the fault specifically isolated to this system / module? Go to Step 2 Go to Section 0D

Vehicle Diagnostics

2 1 Connect Tech 2 to the DLC.

2 Ignition ON, engine OFF.

3 Select transmission data on Tech 2.

Does the Tech 2 display trans mission data? Go to Step 4 Go to 0C Tech 2.

3 1 Check for any applicable S ervice Techline that ma y address the

problem.

2 Perform repair procedures as necessary.

Did a Service Techline procedure correct the condition? System OK Go to Step 4

4 Using Tech 2, check for any transmission D TCs stored in the TCM.

Are any DTCs present?

Go to the

appropriate DTC

Table in this

Section. Go to Step 5

5 On Tech 2, compare the transmission data with the values shown in

the Automatic Transmission Data Lists. Refer to 3.2 Automatic

Transmission Data Lists in this Section.

Are the displayed values nor m al or within typical ranges?

Go to Symptoms

Tables, in Section

7E3 Automatic

Transmission –

5L40-E – Hydraulic /

Mechanical

Diagnosis.

Go to 1.4 Electronic

Component

Description in this

Section.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 30

7E2 – 30

3 Tech 2 – Automatic

Transmission

3.1 Introduction

Use the Tech 2 Data List under the following conditions:

• The Diagnostic System Check – Automatic Transmission has been compl eted.

• The On-Board Diagnostics are function ing correctly.

• No DTCs are present.

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 repl acement of parts.

Only the parameters listed as follows are used in this service information for diagnosing.

Techline

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 31

7E2 – 31

3.2 Automatic Transmission Data Lists

The following Tech 2 values were recorded under the following con diti ons:

Ignition ON

• Engine stopped, ignition i n the ON positio n.

• Closed throttle.

• Transmission selector in the Park position.

• 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.

• Engine, transmission at normal operating temperature.

• Accessories are OFF.

• Brake pedal not applied.

A number of data lists are provided, that can save time when diagnosing symptomatic conditions.

F0: Transmission Data

Tech 2 Display Units Displayed Ignition On Engine Running

Engine Torque Nm Varies Varies

Throttle Position % Varies Varies

Engine Speed RPM 0 RPM Varies

AT Input Speed (Automatic

Transmission) RPM 0 RPM Varies

AT Output Speed (Automatic

Transmission) RPM 0 RPM 0 RPM

Vehicle Speed km/h 0 km/h 0 km/h

Commanded Gear 5 1

Shift Solenoid A Off / On Off Off

Shift Solenoid B Off / On Off On

Shift Solenoid C Off / On Off Off

Estimated Gear Ratio :1 0.00:1 3.98:1

Active Select Off / Enabled Off Off

Active Select Request None / Shift Up / Shift

Down / Invalid None None

Engine Coolant Temperature ° C Varies Varies

Transmission Fluid Temperat ure ° C Varies Varies

Transmission Hot Mode Off / On Off Off

PCS Actual Current (Pressure

Control Solenoid) mA 0 mA Varies

PCS Desired Current (Pressure

Control Solenoid) mA 0 mA Varies

PCS Duty Cycle (Pressure

Control Solenoid) % 0% Varies

High Side Driver 1 Disabled / Enabled Enabled Enabled

TCC PWM Solenoid (Torque

Converter Clutch) % 0% 0%

TCC Slip Speed (T orque

Converter Clutch) RPM 0 RPM Varies

TCC Brake Switch (Torque

Converter Clutch) Closed / Open Closed Closed

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 32

7E2 – 32

Tech 2 Display Units Displayed Ignition On Engine Running

High Side Driver 2 Disabled / Enabled Enabled Enabled

Internal Mode Switch Park / Reverse / Neutral /

Drive 5 / Drive 4 / Drive 3

/ Drive 2 / Invalid Park Park

Internal Mode Switch A High 12V / Low 0V High 12V High 12V

Internal Mode Switch B High 12V / Low 0V Low 0V Low 0V

Internal Mode Switch C High 12V / Low 0V Low 0V Low 0V

Internal Mode Switch P High 12V / Low 0V High 12V High 12V

Latest Shift sec 0.00 sec 0.00 sec

1-2 Shift Time sec 0.00 sec 0.00 sec

2-3 Shift Time sec 0.00 sec 0.00 sec

3-4 Shift Time sec 0.00 sec 0.00 sec

4-5 Shift Time sec 0.00 sec 0.00 sec

Cruise Control Active / Inactive /

Not Programmed Inactive Inactive

A/C Clutch (Air Conditioning) Off / On Off Off

Traction Control Inactive / Active Inactive Inactive

Ignition Voltage V 12 – 14.7 V 12 – 14.7 V

Shift Pattern Active Select / Cruise /

Power / Normal / Detent Normal Normal

F0: Transmission Data List Definitions

Engine Torque

This display indicates the amount of torque that is delivere d from the engine.

Throttle Position

The Throttle Position parameter indicates the position of the throttle. A 0 % reading indicates that the throttle is fully

released. A 100% reading ind icates that the throttle is fully depressed.

Engine Speed

This parameter indicates the rotational speed of the engine expressed in revol utions per minute. Engine speed is

computed by the ECM from the crankshaft position sensor input.

AT Input Speed

The Transmission Input (Shaft) Speed (TISS) sensor parameter displays the rotational speed of the transmission input

shaft expressed in revolutions per minute.

AT Output Speed

The Transmission Output (Shaft) Speed (OSS) sensor parameter displays the rotational speed of the transmissio n outp ut

shaft expressed in revolutions per minute.

Vehicle Speed

The vehicle speed sensor signal is converted by the TCM and is displaye d in km/h.

Commanded Gear

This display indicates the commanded gear of the TCM. With the engine off, ignition on and the selector in the Park

position, it is normal to have ‘5’ displayed on Tech 2.

Shift Solenoid A

The Shift Solenoid A parameter ind icates the current commanded state of the shift solenoids. All three of the 5L4 0-E shift

solenoids are normally-c losed, which means that no fluid passes through when the solenoid is commanded OF F. W hen

the TCM commands the solenoid ON, the solenoid opens and allows fluid to flow through.

Refer to 1.4 Electronic Component Description – Shift Solenoid (SS) Valves in this Section.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 33

7E2 – 33

Shift Solenoid B

The Shift Solenoid B parameter ind icates the current commanded state of the shift solenoids. All three of the 5L4 0-E shift

solenoids are normally-c losed, which means that no fluid passes through when the solenoid is commanded OF F. W hen

the TCM commands the solenoid ON, the solenoid opens and allows fluid to flow through.

Refer to 1.4 Electronic Component Description – Shift Solenoid (SS) Valves in this Section.

Shift Solenoid C

The Shift Solenoid C parameter indicates the current commanded state of the shift solenoids. All three of the 5L40-E shift

solenoids are normally-c losed, which means that no fluid passes through when the solenoid is commanded OF F. W hen

the TCM commands the solenoid ON, the solenoid opens and allows fluid to flow through.

Refer to 1.4 Electronic Component Description – Shift Solenoid (SS) Valves in this Section.

Estimated Gear Ratio

This display is the actual transmission gear ratio as the transmission operates through all drive ra nges including

REVERSE and PARK / NEUTRAL. The gear ratio parameter is obtained by dividing the input shaft speed by the output

shaft speed.

Active Select

When activated by the driver pressing the m omentary switch ‘A/S’ in the centre consol e, this parameter indicates that this

is the current transmission shift mode

Active Select Request

When active select is enabled this request displays the requested status from the ‘+’ or ‘–‘ paddle switches.

Engine Coolant Temperature

The Engine Coolant Temperature (ECT) parameter displays the engine coolant temperature data that the TCM receives

from the ECM on the GMLAN bus. The TCM uses the ECT information to modify shift patterns in cold weather and as a

rationality check for the transmission fl uid temperature sensor.

Transmission Fluid Temperature

The Transmission Fluid Temperature parameter displays the temperature conversion of the voltage input signal to the

TCM from the Transmission Fluid Temperature (TFT) sensor. The TFT sensor is a negative temperature coefficient

thermistor. The resistance decreases as the t emperature increases. As the transmission fluid temperature increases, the

decreasing resistance causes the 5 volt reference voltage to be pulled progressively lower.

Transmission Hot Mode

This display indicates transm ission hot mode operation due to high transmission fluid temperatur e. OFF indicates that

the transmission fluid temperature has not exceeded 132° C. ON indicates that the transmission fluid tem perature has

exceeded 132° C and has not cooled below 129° C for more than 5 seconds.

Pressure Control Solenoid (PCS) Actual Current

The Pressure Control Solenoid (PCS) Actual Current p ara meter displays the actual current flow through the pressur e

control solenoid circuit which is monitored by the TCM. High current results in low line pressure. Low current results in

high line pressure.

Pressure Control Solenoid (PCS) Desired Current

The Pressure Control Solenoid Desired Current displays the amount of current which the TCM has commanded through

the pressure control solenoid circuit. High current results in low line pressure. Low current results in high line pressure.

Pressure Control Solenoid (PCS) Duty Cycle

The Pressure Control Solenoid Duty Cycle parameter displays the commanded state of the press ure co ntrol solenoid

expressed as a percentage of ON time. No current flow indicates zero ON time or 0% duty cycle. High current flow is

approximately 60% duty cycle at idle.

High Side Driver 1

The Transmission Control Mo dule (TCM) provides voltage to automatic transmission internal electrical components,

through two solid state devices , called HSD1 and HSD2. The High Side Driver 1 (HSD1) provides electrical power to the

pressure control solenoid. A normal function of the TCM is to run tests on each driver to ensure that it is functioning

correctly. Provided this testing passes, HSD1 will be disp layed on Tech 2 as ‘Enabled’. If the testing fails, then ‘Disabled’

will be displayed.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 34

7E2 – 34

Torque Converter Clutch (TCC) PWM Solenoid

The Torque Converter Clutch (TCC) PWM Solenoid parameter displays the commanded state of the TCC PWM solenoid

expressed as a percent of ON time. 90% represents a fully energ ised commanded state and 0% represents a de-

energised commanded state.

Torque Converter Clutch (TCC) Slip Speed

Torque Converter Clutch (T CC) Slip Speed parameter displays the difference between the engine rpm and the rpm of the

input shaft of the transmission. A negative value indicates that the engine rpm is less than the rpm of the input shaft,

deceleration. A positive value indicates that the engine rpm is greater than the rpm of the input shaft.

Torque Converter Clutch (TCC) Brake Switch

The Torque Converter Clutch (TCC) Brake Switch parameter displays the status of the TCC brake switch circuit input to

the TCM. When the brake pe dal is released, Tech 2 shoul d indicate OPEN. When the brake pedal is ap plied, Tech 2

should indicate CLOSED.

High Side Driver 2

The Transmission Control Mo dule (TCM) provides voltage to automatic transmission internal electrical components,

through two solid state devices , called HSD1 and HSD2. The High Side Driver 2 (HSD2) provides electrical power to the

shift solenoids and the torque converter cl utch solenoid. A normal function of the TCM is to run tests on each driver to

ensure that it is functioning correctly. Provided this testing passes, HSD2 will be displayed on Tech 2 as ‘Enabled’. If the

testing fails, then ‘Disabled’ will be displayed.

Internal Mode Switch (IMS)

For Tech 2 data purposes, the manual shift shaft switch assembly is referred to as the IMS (Internal Mode Switch). The

IMS displays the decoded status of the four A / B / C / P inputs from the automatic transmission. If a valid combination of

inputs is not received by the TCM, ‘Invalid’ will be displayed. An additional signal is directed to the ECM that is used for

engine controls as well as determining the transmission shift patterns.

Internal Mode Switch A / B / C / P

The Internal Mode Switch (IMS) parameter displays th e four inputs from the automatic tra nsmissio n. HI indicates an

ignition voltage signal and LOW indicates a 0 voltage signal.

Last Shift

This display indicates the actual shift time of the most recent upshift.

Torque Converter Clutch (TCC) Duty Cycle

The Torque Converter Clutch (TCC) Duty Cycle status parameter interprets the solenoid driver feedback voltage signa l

and displays the circuit status on T ech 2. If the voltag e is within the calibration parameters, Tech 2 will display ‘Okay’.

However, if the voltage is low when the solenoid is commanded OFF, Tech 2 will display ‘Short to Ground’. If the voltage

is high when the solenoid is commanded ON, Tech 2 will display ‘Open or Shorted’.

1-2 Shift Time

This display is the actual time of the last shift. The actual shift time is obtained by measuring the time required for the

input shaft to decelerate from the previous ratio to the current ratio.

2–3 Shift Time

This display is the actual time of the last shift. The actual shift time is obtained by measuring the time required for the

input shaft to decelerate from the previous ratio to the current ratio.

3–4 Shift Time

This display is the actual time of the last shift. The actual shift time is obtained by measuring the time required for the

input shaft to decelerate from the previous ratio to the current ratio.

4–5 Shift Time

This display is the actual time of the last shift. The actual shift time is obtained by measuring the time required for the

input shaft to decelerate from the previous ratio to the current ratio.

Cruise Control

When the display indicates ‘Active’, the ECM is allowing cruise control operation. When the display indicates ‘Inactive’,

the ECM has disabled cruise control operation. If the Tech 2 display shows ‘Not Programmed’, . The TCM modifies

upshift and downshift patterns when cruise control is enabled.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 35

7E2 – 35

A/C Clutch

The Air Conditioner (A/C) represents the comm anded state of the A/C clutch control relay. The clutch should be engaged

whenever ‘On’ is displayed. The ECM will then compensate for the additional engine lo ad that is accompanied with the

A/C clutch engaged. An ‘Off’ display indicates that the relay is deactivated.

Traction Control

This parameter indicates if the ECM is reducing torque to a level below that which the driver has comma nded due to

drive wheel slippage. Tech 2 will either display ‘Inactive’ or ‘‘Active’, depe nding on the traction control status.

Ignition Voltage

This represents the system voltage measured by the TCM at its ignition input.

Shift Pattern

This parameter indicates which transmission shift pattern the TCM is currently controlling. The display will show ‘Active

Select’, ‘Cruise’, ‘Power’, ‘Normal’, or ‘Detent’.

F1: TCC Data

Tech 2 Display Units Displayed Ignition On Engine Running

TCC PWM Solenoid (Torque

Converter Clutch) % 0% 0%

TCC Slip Speed (T orque

Converter Clutch) RPM 0 RPM Varies

TCC Brake Switch (Torque

Converter Clutch) Closed / Open Closed Closed

TCC Duty Cycle Circuit (Torque

Converter Clutch) Okay / Open or Shorted /

Short to Ground Okay Okay

High Side Driver 2 Disabled / Enabled Enabled Enabled

High Side Driver 2 Circuit Okay / Open / Short to

Battery / Short to Ground Okay Okay

Throttle Position % Varies Varies

Engine Speed RPM 0 RPM Varies

AT Input Speed (Automatic

Transmission) RPM 0 RPM Varies

AT Output Speed (Automatic

Transmission) RPM 0 RPM 0 RPM

Engine Torque Nm Varies Varies

Vehicle Speed km/h 0 km/h 0 km/h

Commanded Gear 5 1

Engine Coolant Temperature ° C Varies Varies

Transmission Fluid Temperat ure ° C Varies Varies

Estimated Gear Ratio :1 0.00:1 3.98:1

Transmission Hot Mode Off / On Off Off

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 36

7E2 – 36

F1: TCC Data List Definitions

Torque Converter Clutch (TCC) PWM Solenoid

The Torque Converter Clutch (TCC) PWM Solenoid parameter displays the commanded state of the TCC PWM solenoid

expressed as a percent of ON time. 90% represents a fully energ ised commanded state and 0% represents a de-

energised commanded state.

Torque Converter Clutch (TCC) Slip Speed

Torque Converter Clutch (T CC) Slip Speed parameter displays the difference between the engine rpm and the rpm of the

input shaft of the transmission. A negative value indicates that the engine rpm is less than the rpm of the input shaft,

deceleration. A positive value indicates that the engine rpm is greater than the rpm of the input shaft.

Torque Converter Clutch (TCC) Brake Switch

The Torque Converter Clutch (TCC) Brake Switch parameter displays the status of the TCC brake switch circuit input to

the TCM. When the brake pe dal is released, Tech 2 shoul d indicate OPEN. When the brake pedal is ap plied, Tech 2

should indicate CLOSED.

Torque Converter Clutch (TCC) Duty Cycle

The Torque Converter Clutch (TCC) Duty Cycle status parameter interprets the solenoid driver feedback voltage signa l

and displays the circuit status on T ech 2. If the voltag e is within the calibration parameters, Tech 2 will display ‘Okay’.

However, if the voltage is low when the solenoid is commanded OFF, Tech 2 will display ‘Short to Ground’. If the voltage

is high when the solenoid is commanded ON, Tech 2 will display ‘Open or Shorted’.

High Side Driver 2

The Transmission Control Mo dule (TCM) provides voltage to automatic transmission internal electrical components,

through two solid state devices , called HSD1 and HSD2. The High Side Driver 2 (HSD2) provides electrical power to the

shift solenoids and the torque converter cl utch solenoid. A normal function of the TCM is to run tests on each driver to

ensure that it is functioning correctly. Provided this testing passes, HSD2 will be displayed on Tech 2 as ‘Enabled’. If the

testing fails, then ‘Disabled’ will be displayed.

High Side Driver 2 Circuit

The Transmission Control Mo dule (TCM) provides voltage to automatic transmission internal electrical components,

through two solid state devices , called HSD1 and HSD2. The High Side Driver 2 (HSD2) provides electrical power to the

shift solenoids and the torque converter cl utch solenoid. A normal function of the TCM is to run tests on each driver and

circuit to ensure that it is functioning correctly. Dependent on the TCM testing outcome, TECH2 will display ‘Okay’,

‘Open’, ‘Short to Battery’ or ‘Short to Ground’.

Throttle Position

The Throttle Position parameter indicates the position of the throttle. A 0 % reading indicates that the throttle is fully

released. A 100% reading ind icates that the throttle is fully depressed.

Engine Speed

This parameter indicates the rotational speed of the engine expressed in revol utions per minute. Engine speed is

computed by the ECM from the crankshaft position sensor input.

AT Input Speed

The Transmission Input (Shaft) Speed (TISS) sensor parameter displays the rotational speed of the transmission input

shaft expressed in revolutions per minute.

AT Output Speed

The Transmission Output (Shaft) Speed (OSS) sensor parameter displays the rotational speed of the transmissio n outp ut

shaft expressed in revolutions per minute.

Engine Torque

This display indicates the amount of torque that is delivere d from the engine.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 37

7E2 – 37

Vehicle Speed

The vehicle speed sensor signal is converted by the TCM and is displaye d in km/h.

Commanded Gear

This display indicates the commanded gear of the TCM. With the engine off, ignition on and the selector in the Park

position, it is normal to have ‘5’ displayed on Tech 2.

Engine Coolant Temperature

The Engine Coolant Temperature (ECT) parameter displays the engine coolant temperature data that the TCM receives

from the ECM on the GMLAN bus. The TCM uses the ECT information to modify shift patterns in cold weather and as a

rationality check for the transmission fl uid temperature sensor.

Transmission Fluid Temperature

The Transmission Fluid Temperature parameter displays the temperature conversion of the voltage input signal to the

TCM from the Transmission Fluid Temperature (TFT) sensor. The TFT sensor is a negative temperature coefficient

thermistor. The resistance decreases as the t emperature increases. As the transmission fluid temperature increases, the

decreasing resistance causes the 5 volt reference voltage to be pulled progressively lower.

Estimated Gear Ratio

This display is the actual transmission gear ratio as the transmission operates through all drive ranges including Reverse

and Park / Neutral. The gear ratio parameter is obtained by dividing the inp ut shaft speed by the output shaft speed.

Transmission Hot Mode

This display indicates transm ission hot mode operation due to high transmission fluid temperatur e. OFF indicates that

the transmission fluid temperature has not exceeded 132° C. ON indicates that the transmission fluid tem perature has

exceeded 132° C and has not cooled below 129° C for more than 5 seconds.

F2: 1-2 Shift Data

Tech 2 Display Units Displayed Ignition On Engine Running

Shift Solenoid A Off / On Off Off

Shift Solenoid B Off / On Off On

Shift Solenoid C Off / On Off Off

Commanded Gear 5 1

1-2 Shift Time sec 0.00 sec 0.00 sec

1-2 Shift Error sec 0.00 sec 0.00 sec

Shift Solenoid A Circuit Okay / Open or Shorted /

Short to Battery Okay Okay

High Side Driver 2 Disabled / Enabled Enabled Enabled

High Side Driver 2 Circuit Okay / Open / Short to

Battery / Short to Ground Okay Okay

Throttle Position % Varies Varies

Engine Speed RPM 0 RPM Varies

AT Input Speed (Automatic

Transmission) RPM 0 RPM Varies

AT Output Speed (Automatic

Transmission) RPM 0 RPM 0 RPM

Vehicle Speed km/h 0 km/h 0 km/h

Estimated Gear Ratio :1 0.00:1 3.98:1

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 38

7E2 – 38

F2: 1-2 Shift Data List Definitions

Shift Solenoid A

The Shift Solenoid A parameter ind icates the current commanded state of the shift solenoids. All three of the 5L4 0-E shift

solenoids are normally-c losed, which means that no fluid passes through when the solenoid is commanded OF F. W hen

the TCM commands the solenoid ON, the solenoid opens and allows fluid to flow through.

Refer to 1.4 Electronic Component Description – Shift Solenoid (SS) Valves in this Section.

Shift Solenoid B

The Shift Solenoid B parameter ind icates the current commanded state of the shift solenoids. All three of the 5L4 0-E shift

solenoids are normally-c losed, which means that no fluid passes through when the solenoid is commanded OF F. W hen

the TCM commands the solenoid ON, the solenoid opens and allows fluid to flow through.

Refer to 1.4 Electronic Component Description – Shift Sole noid (SS) Valves in this Section.

Shift Solenoid C

The Shift Solenoid C parameter indicates the current commanded state of the shift solenoids. All three of the 5L40-E shift

solenoids are normally-c losed, which means that no fluid passes through when the solenoid is commanded OF F. W hen

the TCM commands the solenoid ON, the solenoid opens and allows fluid to flow through.

Refer to 1.4 Electronic Component Description – Shift Solenoid (SS) Valves in this Section.

Commanded Gear

This display indicates the commanded gear of the TCM. With the engine off, ignition on and the selector in the Park

position, it is normal to have ‘5’ displayed on Tech 2.

1-2 Shift Time

This display is the actual time of the last shift. The actual shift time is obtained by measuring the time required for the

input shaft to decelerate from the previous ratio to the current ratio.

1–2 Shift Error

This display is the difference between the desired shift time and the actual shift time for the specific shift indicated on

Tech 2. The desired shift time is calculated by the TCM. The actual shift time is obtained by measuring t he time required

for the input shaft to decelerate from the previous ratio to the current ratio. If the number i s negative, the actual shift took

longer than desired. If the number is positive, the shift occurred more qui ckly than desired.

Shift Solenoid A Circuit

The Shift Solenoid A Circuit status parameter interprets the solenoid driv er feedback voltage signal and displays the

circuit status on the Tech 2. If the voltage is low when the solenoid is comm anded OFF, Tech 2 will display ‘Open or

Shorted’. If the voltage is high when the solenoid is commanded ON, the T ech 2 will display ‘Short to Battery’. If the

voltage signal is considered normal, the display will show ‘Okay’.

High Side Driver 2

The Transmission Control Mo dule (TCM) provides voltage to automatic transmission internal electrical components,

through two solid state devices , called HSD1 and HSD2. The High Side Driver 2 (HSD2) provides electrical power to the

shift solenoids and the torque converter cl utch solenoid. A normal function of the TCM is to run tests on each driver to

ensure that it is functioning correctly. Provided this testing passes, HSD2 will be displayed on Tech 2 as ‘Enabled’. If the

testing fails, then ‘Disabled’ will be displayed.

High Side Driver 2 Circuit

The Transmission Control Mo dule (TCM) provides voltage to automatic transmission internal electrical components,

through two solid state devices , called HSD1 and HSD2. The High Side Driver 2 (HSD2) provides electrical power to the

shift solenoids and the torque converter cl utch solenoid. A normal function of the TCM is to run tests on each driver and

circuit to ensure that it is functioning correctly. Dependent on the TCM testing outcome, TECH2 will display ‘Okay’,

‘Open’, ‘Short to Battery’ or ‘Short to Ground’.

Throttle Position

The Throttle Position parameter indicates the position of the throttle. A 0 % reading indicates that the throttle is fully

released. A 100% reading ind icates that the throttle is fully depressed.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 39

7E2 – 39

Engine Speed

This parameter indicates the rotational speed of the engine expressed in revol utions per minute. Engine speed is

computed by the ECM from the crankshaft position sensor input.

AT Input Speed

The Transmission Input (Shaft) Speed (TISS) sensor parameter displays the rotational speed of the transmission input

shaft expressed in revolutions per minute.

AT Output Speed

The Transmission Output (Shaft) Speed (OSS) sensor parameter displays the rotational speed of the transmissio n outp ut

shaft expressed in revolutions per minute.

Vehicle Speed

The vehicle speed sensor signal is converted by the TCM and is displaye d in km/h.

Estimated Gear Ratio

This display is the actual transmission gear ratio as the transmission operates through all drive ranges including Reverse

and Park / Neutral. The gear ratio parameter is obtained by dividing the inp ut shaft speed by the output shaft speed.

F3: 2-3 Shift Data

Tech 2 Display Units Displayed Ignition On Engine Running

Shift Solenoid A Off / On Off Off

Shift Solenoid B Off / On Off On

Shift Solenoid C Off / On Off Off

Commanded Gear 5 1

2-3 Shift Time sec 0.00 sec 0.00 sec

2-3 Shift Error sec 0.00 sec 0.00 sec

Shift Solenoid B Circuit Okay / Open or Shorted /

Short to Battery Okay Okay

High Side Driver 2 Disabled / Enabled Enabled Enabled

High Side Driver 2 Circuit Okay / Open / Short to

Battery / Short to Ground Okay Okay

Throttle Position % Varies Varies

Engine Speed RPM 0 RPM Varies

AT Input Speed (Automatic

Transmission) RPM 0 RPM Varies

AT Output Speed (Automatic

Transmission) RPM 0 RPM 0 RPM

Vehicle Speed km/h 0 km/h 0 km/h

Estimated Gear Ratio :1 0.00:1 3.98:1

F3: 2-3 Shift Data List Definitions

Shift Solenoid A

The Shift Solenoid A parameter ind icates the current commanded state of the shift solenoids. All three of the 5L4 0-E shift

solenoids are normally-c losed, which means that no fluid passes through when the solenoid is commanded OF F. W hen

the TCM commands the solenoid ON, the solenoid opens and allows fluid to flow through.

Refer to 1.4 Electronic Component Description – Shift Solenoid (SS) Valves in this Section.

Shift Solenoid B

The Shift Solenoid B parameter ind icates the current commanded state of the shift solenoids. All three of the 5L4 0-E shift

solenoids are normally-c losed, which means that no fluid passes through when the solenoid is commanded OF F. W hen

the TCM commands the solenoid ON, the solenoid opens and allows fluid to flow through.

Refer to 1.4 Electronic Component Description – Shift Sole noid (SS) Valves in this Section.

Shift Solenoid C

The Shift Solenoid C parameter indicates the current commanded state of the shift solenoids. All three of the 5L40-E shift

solenoids are normally-c losed, which means that no fluid passes through when the solenoid is commanded OF F. W hen

the TCM commands the solenoid ON, the solenoid opens and allows fluid to flow through.

Refer to 1.4 Electronic Component Description – Shift Solenoid (SS) Valves in this Section.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 40

7E2 – 40

Commanded Gear

This display indicates the commanded gear of the TCM. With the engine off, ignition on and the selector in the Park

position, it is normal to have ‘5’ displayed on Tech 2.

2-3 Shift Time

This display is the actual time of the last shift. The actual shift time is obtained by measuring the time required for the

input shaft to decelerate from the previous ratio to the current ratio.

2-3 Shift Error

This display is the difference between the desired shift time and the actual shift time for the specific shift indicated on

Tech 2. The desired shift time is calculated by the TCM. The actual shift time is obtained by measuring t he time required

for the input shaft to decelerate from the previous ratio to the current ratio. If the number i s negative, the actual shift took

longer than desired. If the number is positive, the shift occurred more qui ckly than desired.

Shift Solenoid B Circuit

The Shift Solenoid B Circuit status parameter interprets the solenoid driv er feedback voltage signal and displays the

circuit status on the Tech 2. If the voltage is low when the solenoid is comm anded OFF, Tech 2 will display ‘Open or

Shorted’. If the voltage is high when the solenoid is commanded ON, the T ech 2 will display ‘Short to Battery’. If the

voltage signal is considered normal, the display will show ‘Okay’.

High Side Driver 2

The Transmission Control Mo dule (TCM) provides voltage to automatic transmission internal electrical components,

through two solid state devices , called HSD1 and HSD2. The High Side Driver 2 (HSD2) provides electrical power to the

shift solenoids and the torque converter cl utch solenoid. A normal function of the TCM is to run tests on each driver to

ensure that it is functioning correctly. Provided this testing passes, HSD2 will be displayed on Tech 2 as ‘Enabled’. If the

testing fails, then ‘Disabled’ will be displayed.

High Side Driver 2 Circuit

The Transmission Control Mo dule (TCM) provides voltage to automatic transmission internal electrical components,

through two solid state devices , called HSD1 and HSD2. The High Side Driver 2 (HSD2) provides electrical power to the

shift solenoids and the torque converter cl utch solenoid. A normal function of the TCM is to run tests on each driver and

circuit to ensure that it is functioning correctly. Dependent on the TCM testing outcome, TECH2 will display ‘Okay’,

‘Open’, ‘Short to Battery’ or ‘Short to Ground’.

Throttle Position

The Throttle Position parameter indicates the position of the throttle. A 0 % reading indicates that the throttle is fully

released. A 100% reading ind icates that the throttle is fully depressed.

Engine Speed

This parameter indicates the rotational speed of the engine expressed in revol utions per minute. Engine speed is

computed by the ECM from the crankshaft position sensor input.

AT Input Speed

The Transmission Input (Shaft) Speed (TISS) sensor parameter displays the rotational speed of the transmission input

shaft expressed in revolutions per minute.

AT Output Speed

The Transmission Output (Shaft) Speed (OSS) sensor parameter displays the rotational speed of the transmissio n outp ut

shaft expressed in revolutions per minute.

Vehicle Speed

The vehicle speed sensor signal is converted by the TCM and is displaye d in km/h.

Estimated Gear Ratio

This display is the actual transmission gear ratio as the transmission operates through all drive ra nges including

REVERSE and PARK / NEUTRAL. The gear ratio parameter is obtained by dividing the input shaft speed by the output

shaft speed.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 41

7E2 – 41

F4: 3-4 Shift Data

Tech 2 Display Units Displayed Ignition On Engine Running

Shift Solenoid A Off / On Off Off

Shift Solenoid B Off / On Off On

Shift Solenoid C Off / On Off Off

Commanded Gear 5 1

3-4 Shift Time sec 0.00 sec 0.00 sec

3-4 Shift Error sec 0.00 sec 0.00 sec

High Side Driver 2 Disabled / Enabled Enabled Enabled

High Side Driver 2 Circuit Okay / Open / Short to

Battery / Short to Ground Okay Okay

Throttle Position % Varies Varies

Engine Speed RPM 0 RPM Varies

AT Input Speed (Automatic

Transmission) RPM 0 RPM Varies

AT Output Speed (Automatic

Transmission) RPM 0 RPM 0 RPM

Vehicle Speed km/h 0 km/h 0 km/h

Estimated Gear Ratio :1 0.00:1 3.98:1

F4: 3-4 Shift Data List Definitions

Shift Solenoid A

The Shift Solenoid A parameter ind icates the current commanded state of the shift solenoids. All three of the 5L4 0-E shift

solenoids are normally-c losed, which means that no fluid passes through when the solenoid is commanded OF F. W hen

the TCM commands the solenoid ON, the solenoid opens and allows fluid to flow through.

Refer to 1.4 Electronic Component Description – Shift Solenoid (SS) Valves in this Section.

Shift Solenoid B

The Shift Solenoid B parameter ind icates the current commanded state of the shift solenoids. All three of the 5L4 0-E shift

solenoids are normally-c losed, which means that no fluid passes through when the solenoid is commanded OF F. W hen

the TCM commands the solenoid ON, the solenoid opens and allows fluid to flow through.

Refer to 1.4 Electronic Component Description – Shift Sole noid (SS) Valves in this Section.

Shift Solenoid C

The Shift Solenoid C parameter indicates the current commanded state of the shift solenoids. All three of the 5L40-E shift

solenoids are normally-c losed, which means that no fluid passes through when the solenoid is commanded OF F. W hen

the TCM commands the solenoid ON, the solenoid opens and allows fluid to flow through.

Refer to 1.4 Electronic Component Description – Shift Solenoid (SS) Valves in this Section.

Commanded Gear

This display indicates the commanded gear of the TCM. With the engine off, ignition on and the selector in the Park

position, it is normal to have ‘5’ displayed on Tech 2.

3-4 Shift Time

This display is the actual time of the last shift. The actual shift time is obtained by measuring the time required for the

input shaft to decelerate from the previous ratio to the current ratio.

3-4 Shift Error

This display is the difference between the desired shift time and the actual shift time for the specific shift indicated on

Tech 2. The desired shift time is calculated by the TCM. The actual shift time is obtained by measuring t he time required

for the input shaft to decelerate from the previous ratio to the current ratio. If the number i s negative, the actual shift took

longer than desired. If the number is positive, the shift occurred more qui ckly than desired.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 42

7E2 – 42

High Side Driver 2

The Transmission Control Mo dule (TCM) provides voltage to automatic transmission internal electrical components,

through two solid state devices , called HSD1 and HSD2. The High Side Driver 2 (HSD2) provides electrical power to the

shift solenoids and the torque converter cl utch solenoid. A normal function of the TCM is to run tests on each driver to

ensure that it is functioning correctly. Provided this testing passes, HSD2 will be displayed on Tech 2 as ‘Enabled’. If the

testing fails, then ‘Disabled’ will be displayed.

High Side Driver 2 Circuit

The Transmission Control Mo dule (TCM) provides voltage to automatic transmission internal electrical components,

through two solid state devices , called HSD1 and HSD2. The High Side Driver 2 (HSD2) provides electrical power to the

shift solenoids and the torque converter cl utch solenoid. A normal function of the TCM is to run tests on each driver and

circuit to ensure that it is functioning correctly. Dependent on the TCM testing outcome, TECH2 will display ‘Okay’,

‘Open’, ‘Short to Battery’ or ‘Short to Ground’.

Throttle Position

The Throttle Position parameter indicates the position of the throttle. A 0 % reading indicates that the throttle is fully

released. A 100% reading ind icates that the throttle is fully depressed.

Engine Speed

This parameter indicates the rotational speed of the engine expressed in revol utions per minute. Engine speed is

computed by the ECM from the crankshaft position sensor input.

AT Input Speed

The Transmission Input (Shaft) Speed (TISS) sensor parameter displays the rotational speed of the transmission input

shaft expressed in revolutions per minute.

AT Output Speed

The Transmission Output (Shaft) Speed (OSS) sensor parameter displays the rotational speed of the transmissio n outp ut

shaft expressed in revolutions per minute.

Vehicle Speed

The vehicle speed sensor signal is converted by the TCM and is displaye d in km/h.

Estimated Gear Ratio

This display is the actual transmission gear ratio as the transmission operates through all drive ra nges including

REVERSE and PARK / NEUTRAL. The gear ratio parameter is obtained by dividing the input shaft speed by the output

shaft speed.

F5: 4-5 Shift Data

Tech 2 Display Units Displayed Ignition On Engine Running

Shift Solenoid A Off / On Off Off

Shift Solenoid B Off / On Off On

Shift Solenoid C Off / On Off Off

Commanded Gear 5 1

4-5 Shift Time sec 0.00 sec 0.00 sec

4-5 Shift Error sec 0.00 sec 0.00 sec

Shift Solenoid C Circuit Okay / Open or Shorted /

Short to Battery Okay Okay

High Side Driver 2 Disabled / Enabled Enabled Enabled

High Side Driver 2 Circuit Okay / Open / Short to

Battery / Short to Ground Okay Okay

Throttle Position % Varies Varies

Engine Speed RPM 0 RPM Varies

AT Input Speed (Automatic

Transmission) RPM 0 RPM Varies

AT Output Speed (Automatic

Transmission) RPM 0 RPM 0 RPM

Vehicle Speed km/h 0 km/h 0 km/h

Estimated Gear Ratio :1 0.00:1 3.98:1

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 43

7E2 – 43

F5: 4-5 Shift Data List Definitions

Shift Solenoid A

The Shift Solenoid A parameter ind icates the current commanded state of the shift solenoids. All three of the 5L4 0-E shift

solenoids are normally-c losed, which means that no fluid passes through when the solenoid is commanded OF F. W hen

the TCM commands the solenoid ON, the solenoid opens and allows fluid to flow through.

Refer to 1.4 Electronic Component Description – Shift Solenoid (SS) Valves in this Section.

Shift Solenoid B

The Shift Solenoid B parameter ind icates the current commanded state of the shift solenoids. All three of the 5L4 0-E shift

solenoids are normally-c losed, which means that no fluid passes through when the solenoid is commanded OF F. W hen

the TCM commands the solenoid ON, the solenoid opens and allows fluid to flow through.

Refer to 1.4 Electronic Component Description – Shift Sole noid (SS) Valves in this Section.

Shift Solenoid C

The Shift Solenoid C parameter indicates the current commanded state of the shift solenoids. All three of the 5L40-E shift

solenoids are normally-c losed, which means that no fluid passes through when the solenoid is commanded OF F. W hen

the TCM commands the solenoid ON, the solenoid opens and allows fluid to flow through.

Refer to 1.4 Electronic Component Description – Shift Solenoid (SS) Valves in this Section.

Commanded Gear

This display indicates the commanded gear of the TCM. With the engine off, ignition on and the selector in the Park

position, it is normal to have ‘5’ displayed on Tech 2.

4-5 Shift Time

This display is the actual time of the last shift. The actual shift time is obtained by measuring the time required for the

input shaft to decelerate from the previous ratio to the current ratio.

4-5 Shift Error

This display is the difference between the desired shift time and the actual shift time for the specific shift indicated on

Tech 2. The desired shift time is calculated by the TCM. The actual shift time is obtained by measuring t he time required

for the input shaft to decelerate from the previous ratio to the current ratio. If the number i s negative, the actual shift took

longer than desired. If the number is positive, the shift occurred more qui ckly than desired.

Shift Solenoid C Circuit

The Shift Solenoid B Circuit status parameter interprets the solenoid driv er feedback voltage signal and displays the

circuit status on the Tech 2. If the voltage is low when the solenoid is commanded OFF, Tech 2 will display ‘Open’, or

‘Short to Ground’. If the voltage is high when the sole noid is commanded ON, the Tech 2 will displa y ‘Short to Battery’. If

the voltage signal is consider ed normal, the display will show ‘Okay’.

High Side Driver 2

The Transmission Control Mo dule (TCM) provides voltage to automatic transmission internal electrical components,

through two solid state devices , called HSD1 and HSD2. The High Side Driver 2 (HSD2) provides electrical power to the

shift solenoids and the torque converter cl utch solenoid. A normal function of the TCM is to run tests on each driver to

ensure that it is functioning correctly. Provided this testing passes, HSD2 will be displayed on Tech 2 as ‘Enabled’. If the

testing fails, then ‘Disabled’ will be displayed.

High Side Driver 2 Circuit

The Transmission Control Mo dule (TCM) provides voltage to automatic transmission internal electrical components,

through two solid state devices , called HSD1 and HSD2. The High Side Driver 2 (HSD2) provides electrical power to the

shift solenoids and the torque converter cl utch solenoid. A normal function of the TCM is to run tests on each driver and

circuit to ensure that it is functioning correctly. Dependent on the TCM testing outcome, TECH2 will display ‘Okay’,

‘Open’, ‘Short to Battery’ or ‘Short to Ground’.

Throttle Position

The Throttle Position parameter indicates the position of the throttle. A 0 % reading indicates that the throttle is fully

released. A 100% reading ind icates that the throttle is fully depressed.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 44

7E2 – 44

Engine Speed

This parameter indicates the rotational speed of the engine expressed in revol utions per minute. Engine speed is

computed by the ECM from the crankshaft position sensor input.

AT Input Speed

The Transmission Input (Shaft) Speed (TISS) sensor parameter displays the rotational speed of the transmission input

shaft expressed in revolutions per minute.

AT Output Speed

The Transmission Output (Shaft) Speed (OSS) sensor parameter displays the rotational speed of the transmissio n outp ut

shaft expressed in revolutions per minute.

Vehicle Speed

The vehicle speed sensor signal is converted by the TCM and is displaye d in km/h.

Estimated Gear Ratio

This display is the actual transmission gear ratio as the transmission operates through all drive ra nges including

REVERSE and PARK / NEUTRAL. The gear ratio parameter is obtained by dividing the input shaft speed by the output

shaft speed.

F6: Pressure Control Solenoid Data

Tech 2 Display Units Displayed Ignition On Engine Running

PCS Actual Current (Pressure

Control Solenoid) mA 0 mA Varies

PCS Desired Current (Pressure

Control Solenoid) mA 0 mA Varies

PCS Duty Cycle (Pressure

Control Solenoid) % 0% Varies

High Side Driver 1 Disabled / Enabled Enabled Enabled

High Side Driver 1 Circuit Okay / Open / Short to

Battey / Short to Ground Okay Okay

Engine Speed RPM 0 RPM Varies

Transmission Fluid Temperat ure ° C Varies Varies

Throttle Position % Varies Varies

Vehicle Speed km/h 0 km/h 0 km/h

Commanded Gear – 5 1

F6: Pressure Control Solenoid Data List Definitions

Pressure Control Solenoid (PCS) Actual Current

The Pressure Control Solenoid (PCS) Actual Current p ara meter displays the actual current flow through the pressur e

control solenoid circuit which is monitored by the TCM. High current results in low line pressure. Low current results in

high line pressure.

Pressure Control Solenoid (PCS) Desired Current

The Pressure Control Solenoid Desired Current displays the amount of current which the TCM has commanded through

the pressure control solenoid circuit. High current results in low line pressure. Low current results in high line pressure.

Pressure Control Solenoid (PCS) Duty Cycle

The Pressure Control Solenoid Duty Cycle parameter displays the commanded state of the press ure co ntrol solenoid

expressed as a percentage of ON time. No current flow indicates zero ON time or 0% duty cycle. High current flow is

approximately 60% duty cycle at idle.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 45

7E2 – 45

High Side Driver 1

The Transmission Control Mo dule (TCM) provides voltage to automatic transmission internal electrical components,

through two solid state devices , called HSD1 and HSD2. The High Side Driver 1 (HSD1) provides electrical power to the

pressure control solenoid. A normal function of the TCM is to run tests on each driver to ensure that it is functioning

correctly. Provided this testing passes, HSD1 will be disp layed on Tech 2 as ‘Enabled’. If the testing fails, then ‘Disabled’

will be displayed.

High Side Driver 1 Circuit

The Transmission Control Mo dule (TCM) provides voltage to automatic transmission internal electrical components,

through two solid state devices , called HSD1 and HSD2. The High Side Driver 1 (HSD1) provides electrical power to the

pressure control solenoid. A normal function of the TCM is to run tests on each driver and circuit to ensure that it is

functioning correctly. Dependent on the TCM testing outcome, TECH2 will displa y ‘Okay’, ‘Open’, ‘Short to Battery’ or

‘Short to Ground’.

Engine Speed

This parameter indicates the rotational speed of the engine expressed in revol utions per minute. Engine speed is

computed by the ECM from the crankshaft position sensor input.

Transmission Fluid Temperature

The Transmission Fluid Temperature parameter displays the temperature conversion of the voltage input signal to the

TCM from the Transmission Fluid Temperature (TFT) sensor. The TFT sensor is a negative temperature coefficient

thermistor. The resistance decreases as the t emperature increases. As the transmission fluid temperature increases, the

decreasing resistance causes the 5 volt reference voltage to be pulled progressively lower.

Throttle Position

The Throttle Position parameter indicates the position of the throttle. A 0 % reading indicates that the throttle is fully

released. A 100% reading ind icates that the throttle is fully depressed.

Vehicle Speed

The vehicle speed sensor signal is converted by the TCM and is displaye d in km/h.

Commanded Gear

This display indicates the commanded gear of the TCM. With the engine off, ignition on and the selector in the Park

position, it is normal to have ‘5’ displayed on Tech 2.

F7: Transmission Adapts

F0: 1-2 Adapt Data

Tech 2 Display Units Displayed Ignition On Engine Running

1-2 Shift Time sec 0.00 sec 0.00 sec

1-2 Shift Error sec 0.00 sec 0.00 sec

Current TAP Cell (Transmission

Adaptive Pressure) 0 0

Throttle Position % Varies Varies

1-2 TAP Cell 1 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

1-2 TAP Cell 2 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

1-2 TAP Cell 3 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

1-2 TAP Cell 4 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 46

7E2 – 46

Tech 2 Display Units Displayed Ignition On Engine Running

1-2 TAP Cell 5 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

1-2 TAP Cell 6 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

1-2 TAP Cell 7 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

1-2 TAP Cell 8 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

1-2 TAP Cell 9 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

1-2 TAP Cell 10 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

1-2 TAP Cell 11 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

1-2 TAP Cell 12 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

1-2 TAP Cell 13 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

1-2 TAP Cell 14 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

1-2 TAP Cell 15 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

1-2 TAP Cell 16 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

1-2 TAP Cell 17 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

F0: 1-2 Adapt Data List Definitions

1-2 Shift Time

This display is the actual time of the last shift. The actual shift time is obtained by measuring the time required for

the input shaft to decelerate from the previous ratio to the current ratio.

1–2 Shift Error

This display is the difference between the desired shift time and the actual shift time for the specific shift indicated

on Tech 2. The desired shift time is calculated by the TCM. The actual shift time is obtained b y measur ing the time

required for the input shaft to decelerate from the previous ratio to the current ratio. If the number is negative, the

actual shift took longer than desired. If the number is positive, the shift occurred more quickly than desired.

Current TAP Cell

The current Transmission Adaptive Press ure cell, is that cell the TCM is currently working in, to trim the fluid

pressure to maintain the calibrated shift timing.

Throttle Position

The Throttle Position parameter indicates the position of the throttle. A 0 % reading indicates that the throttle is fully

released. A 100% reading ind icates that the throttle is fully depressed.

1–2 TAP Cell (1 – 17)

The 1–2 Transmission Adaptive Pressure (TAP) Cell param eter displays the amount of adaptive pressure, based

on 17 N.m of engine torque increment per cell, added or subtracted from shift pressure during an upshift. A positive

number indicates that the TCM has detected long shifts and has increased the PC solenoid duty cycle to decrease

shift time. A negative number indicates that the TCM has detected short shifts decreased the PC solenoid duty ycle

to increase shift time.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 47

7E2 – 47

F1: 2-3 Adapt Data

Tech 2 Display Units Displayed Ignition On Engine Running

2-3 Shift Time sec 0.00 sec 0.00 sec

2-3 Shift Error sec 0.00 sec 0.00 sec

Current TAP Cell (Transmission

Adaptive Pressure) 0 0

Throttle Position % Varies Varies

2-3 TAP Cell 1 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

2-3 TAP Cell 2 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

2-3 TAP Cell 3 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

2-3 TAP Cell 4 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

2-3 TAP Cell 5 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

2-3 TAP Cell 6 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

2-3 TAP Cell 7 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

2-3 TAP Cell 8 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

2-3 TAP Cell 9 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

2-3 TAP Cell 10 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

2-3 TAP Cell 11 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

2-3 TAP Cell 12 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

2-3 TAP Cell 13 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

2-3 TAP Cell 14 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

2-3 TAP Cell 15 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

2-3 TAP Cell 16 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

2-3 TAP Cell 17 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

F1: 2-3 Adapt Data List Definitions

2–3 Shift Time

This display is the actual time of the last shift. The actual shift time is obtained by measuring the time required for

the input shaft to decelerate from the previous ratio to the current ratio.

2–3 Shift Error

This display is the difference between the desired shift time and the actual shift time for the specific shift indicated

on the Tech 2. The desired shift time is calcul ated by the TCM. The actual shift time is obtained by measuring the

time required for the input shaft to deceler ate from the previous ratio to the current ratio. If the number is negative,

the actual shift took longer than desired. If the number is positive, the shift occurred more quickly than desired.

Current TAP Cell

The current Transmission Adaptive Press ure cell, is that cell the TCM is currently working in, to trim the fluid

pressure, to maintain the calibrated shift timing.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 48

7E2 – 48

Throttle Position

The Throttle Position parameter indicates the position of the throttle. A 0 % reading indicates that the throttle is fully

released. A 100% reading ind icates that the throttle is fully depressed.

2–3 TAP Cell (1 – 17)

The 2–3 Transmission Adaptive Pressure (TAP) Cell param eter displays the amount of adaptive pressure, based

on 17 N.m of engine torque increment per cell, added or subtracted from shift pressure during an upshift. A positive

number indicates that the TCM has detected long shifts and has increased the PC solenoid duty cycle to decrease

shift time. A negative number indicates that the TCM has detected short shifts decreased the PC solen oi d duty

cycle to increase shift time.

F2: 3-4 Adapt Data

Tech 2 Display Units Displayed Ignition On Engine Running

3-4 Shift Time sec 0.00 sec 0.00 sec

3-4 Shift Error sec 0.00 sec 0.00 sec

Current TAP Cell (Transmission

Adaptive Pressure) 0 0

Throttle Position % Varies Varies

3-4 TAP Cell 1 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

3-4 TAP Cell 2 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

3-4 TAP Cell 3 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

3-4 TAP Cell 4 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

3-4 TAP Cell 5 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

3-4 TAP Cell 6 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

3-4 TAP Cell 7 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

3-4 TAP Cell 8 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

3-4 TAP Cell 9 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

3-4 TAP Cell 10 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

3-4 TAP Cell 11 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

3-4 TAP Cell 12 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

3-4 TAP Cell 13 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

3-4 TAP Cell 14 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

3-4 TAP Cell 15 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

3-4 TAP Cell 16 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

3-4 TAP Cell 17 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 49

7E2 – 49

F2: 3-4 Adapt Data List Definitions

3–4 Shift Time

This display is the actual time of the last shift. The actual shift time is obtained by measuring the time required for

the input shaft to decelerate from the previous ratio to the current ratio.

3–4 Shift Error

This display is the difference between the desired shift time and the actual shift time for the specific shift indicated

on the Tech 2. The desired shift time is calcul ated by the TCM. The actual shift time is obtained by measuring the

time required for the input shaft to deceler ate from the previous ratio to the current ratio. If the number is negative,

the actual shift took longer than desired. If the number is positive, the shift occurred more quickly than desired.

Current TAP Cell

The current Transmission Adaptive Press ure cell, is that cell the TCM is currently working in, to trim the fluid

pressure, to maintain the calibrated shift timing.

Throttle Position

The Throttle Position parameter indicates the position of the throttle. A 0 % reading indicates that the throttle is fully

released. A 100% reading ind icates that the throttle is fully depressed.

3–4 TAP Cell (1 – 17)

The 3–4 Transmission Adaptive Pressure (TAP) Cell param eter displays the amount of adaptive pressure, based

on 17 N.m of engine torque increment per cell, added or subtracted from shift pressure during an upshift. A positive

number indicates that the TCM has detected long shifts and has increased the PC solenoid duty cycle to decrease

shift time. A negative number indicates that the TCM has detected short shifts decreased the PC solen oi d duty

cycle to increase shift time.

F3: 4-5 Adapt Data

Tech 2 Display Units Displayed Ignition On Engine Running

4-5 Shift Time sec 0.00 sec 0.00 sec

4-5 Shift Error sec 0.00 sec 0.00 sec

Current TAP Cell (Transmission

Adaptive Pressure) 0 0

Throttle Position % Varies Varies

4-5 TAP Cell 1 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

4-5 TAP Cell 2 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

4-5 TAP Cell 3 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

4-5 TAP Cell 4 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

4-5 TAP Cell 5 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

4-5 TAP Cell 6 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

4-5 TAP Cell 7 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

4-5 TAP Cell 8 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

4-5 TAP Cell 9 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 50

7E2 – 50

Tech 2 Display Units Displayed Ignition On Engine Running

4-5 TAP Cell 10 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

4-5 TAP Cell 11 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

4-5 TAP Cell 12 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

4-5 TAP Cell 13 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

4-5 TAP Cell 14 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

4-5 TAP Cell 15 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

4-5 TAP Cell 16 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

4-5 TAP Cell 17 (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

F3: 4-5 Adapt Data List Definitions

4–5 Shift Time

This display is the actual time of the last shift. The actual shift time is obtained by measuring the time required for

the input shaft to decelerate from the previous ratio to the current ratio.

4–5 Shift Error

This display is the difference between the desired shift time and the actual shift time for the specific shift indicated

on the Tech 2. The desired shift time is calcul ated by the TCM. The actual shift time is obtained by measuring the

time required for the input shaft to deceler ate from the previous ratio to the current ratio. If the number is negative,

the actual shift took longer than desired. If the number is positive, the shift occurred more quickly than desired.

Current TAP Cell

The current Transmission Adaptive Press ure cell, is that cell the TCM is currently working in, to trim the fluid

pressure, to maintain the calibrated shift timing.

Throttle Position

The Throttle Position parameter indicates the position of the throttle. A 0 % reading indicates that the throttle is fully

released. A 100% reading ind icates that the throttle is fully depressed.

4–5 TAP Cell (1 – 17)

The 4–5 Transmission Adaptive Pressure (TAP) Cell param eter displays the amount of adaptive pressure, based

on 17 N.m of engine torque increment per cell, added or subtracted from shift pressure during an upshift. A positive

number indicates that the TCM has detected long shifts and has increased the PC solenoid duty cycle to decrease

shift time. A negative number indicates that the TCM has detected short shifts decreased the PC solen oi d duty

cycle to increase shift time.

F4: Steady State Adapt Data

Tech 2 Display Units Displayed Ignition On Engine Running

Current TAP Cell (Transmission

Adaptive Pressure) 0 0

Throttle Position % Varies Varies

Gear 1 TAP Cell (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

TCC 1 TAP Cell (T ransmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

Gear 2 TAP Cell (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

TCC 2 TAP Cell (T ransmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

Gear 3 TAP Cell (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

TCC 3 TAP Cell (T ransmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 51

7E2 – 51

Tech 2 Display Units Displayed Ignition On Engine Running

Gear 4 TAP Cell (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

TCC 4 TAP Cell (T ransmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

Gear 5 TAP Cell (Transmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

TCC 5 TAP Cell (T ransmission

Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

Reverse Gear TAP Cell

(Transmission Adaptive Pressure) kPa 0.00 kPa 0.00 kPa

F4: Steady State Adapt Data List Defini tio ns

Current TAP Cell

The current Transmission Adaptive Press ure cell, is that cell the TCM is currently working in, to trim the fluid

pressure, to maintain the calibrated shift timing.

Throttle Position

The Throttle Position parameter indicates the position of the throttle. A 0 % reading indicates that the throttle is fully

released. A 100% reading ind icates that the throttle is fully depressed.

Gear 1 TAP Cell

The Steady State Transmission Adapt Pressure (TAP) Gear 1 parameter displays the amount of pressure used to

help prevent transmission component slip. By analysing the transmission gear ratio when commanding first gear,

the TCM will command additional line pressure to maintain correct first gear ratio. The amount of additional

pressure is determined by the T CM and is used to increase the base line pressure. T he larger the value, the

greater the increase to line pressure.

TCC 1 TAP Cell

The Steady State Transmission Adapt Pressure (TAP) Gear 1 with Torque Converter Clutch (TCC) apply

parameter, displays the amount of pressure used to help prevent transmission com ponent slip. By analysing the

transmission gear ratio when commanding first gear and the TCC ‘ON’, the TCM will command additional li ne

pressure to maintain correct first gear ratio with the TCC applied. The amount of additional pressure is determined

by the TCM and is used to increase the base line pressure. The larger the value, the greater the increas e to line

pressure.

Gear 2 TAP Cell

The Steady State Transmission Adapt Pressure (TAP) Gear 2 parameter displays the amount of pressure used to

help prevent transmission component slip. By analysing the transmission gear ratio when commanding second

gear, the TCM will command additional line pressure to maintain correct second gear ratio. T he amount of

additional pressure is determined by the TCM and is used to increase the base line pressure. The larger the value,

the greater the increase to line pressure.

TCC 2 TAP Cell

The Steady State Transmission Adapt Pressure (TAP) Gear 2 with Torque Converter Clutch (TCC) apply

parameter displays the amount of pressure used to help prevent transmission component slip. By analysi ng the

transmission gear ratio when commandin g second gear and the TCC on, the T CM will command additional line

pressure to maintain correct second gear ratio with the TCC app lied. The amount of additional pressure is

determined by the TCM and is used to incre ase the base line pressure. The larger the value, the greater the

increase to line pressure.

Gear 3 TAP Cell

The Steady State Transmission Adapt Pressure (TAP) Gear 3 parameter displays the amount of pressure used to

help prevent transmission component slip. By analysing the transmission gear ratio when commanding third gear,

the TCM will command additional line pressure to maintain correct third gear ratio. The amount of additiona l

pressure is determined by the T CM and is used to increase the base line pressure. T he larger the value, the

greater the increase to line pressure.

TCC 3 TAP Cell

The Steady State Transmission Adapt Pressure (TAP) Gear 3 with Torque Converter Clutch (TCC) apply

parameter displays the amount of pressure used to help prevent transmission component slip. By analysi ng the

transmission gear ratio when commanding third gear and the TCC on, the TCM will command a dditional line

pressure to maintain correct third gear ratio with the TCC applied. The amount of additional pressure is determined

by the TCM and is used to increase the base line pressure. The larger the value, the greater the increas e to line

pressure.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 52

7E2 – 52

Gear 4 TAP Cell

The Steady State Transmission Adapt Pressure (TAP) Gear 4 parameter displays the amount of pressure used to

help prevent transmission component slip. By analysing the transmission gear ratio when commanding fourth gear,

the TCM will command additional line pressure to maintain correct fourth gear ratio. The amount of addition al

pressure is determined by the T CM and is used to increase the base line pressure. T he larger the value, the

greater the increase to line pressure.

TCC 4 TAP Cell

The Steady State Transmission Adapt Pressure (TAP) Gear 4 with Torque Converter Clutch (TCC) apply

parameter displays the amount of pressure used to help prevent transmission component slip. By analysi ng the

transmission gear ratio when commanding fourth gear and the TCC on, the TCM will command additio nal line

pressure to maintain correct fourth gear ratio with the TCC applied. The amount of additional pressur e i s

determined by the TCM and is used to incre ase the base line pressure. The larger the value, the greater the

increase to line pressure.

Gear 5 TAP Cell

The Steady State Transmission Adapt Pressure (TAP) Gear 5 parameter displays the amount of pressure used to

help prevent transmission component slip. By analysing the transmission gear ratio when commanding fifth gear,

the TCM will command additional line pressure to maintain correct fifth gear ratio. The amount of additional

pressure is determined by the T CM and is used to increase the base line pressure. T he larger the value, the

greater the increase to line pressure.

TCC 5 TAP Cell

The Steady State Transmission Adapt Pressure (TAP) Gear 5 with Torque Converter Clutch (TCC) apply

parameter displays the amount of pressure used to help prevent transmission component slip. By analysi ng the

transmission gear ratio when commanding fifth gear and the TCC on, the TCM will command additional line

pressure to maintain correct fifth gear ratio with the TCC applied. The amount of additional pressure is determined

by the TCM and is used to increase the base line pressure. The larger the value, the greater the increas e to line

pressure.

Reverse Gear TAP Cell

The Steady State Transmission Adapt Pressure (TAP) Reverse Gear parameter displays the amount of pressure

used to help prevent transmission com ponent slip. By analysing the transmission gear ratio when commanding

reverse gear, the TCM will command additio nal line pressure to maintain correct reverse gear ratio. The amount of

additional pressure is determined by the TCM and is used to increase the base line pressure. The larger the value,

the greater the increase to line pressure.

F8: System Identification

Identifier Number Varies Varies

Partnumber Number Varies Varies

Hardware Number Number Varies Varies

Alpha Code Letters Varies Varies

Software Version Number Number Varies Varies

Software Partnumber Number Varies Varies

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 53

7E2 – 53

3.3 Tech 2 – Output Controls

In this test mode, the Tech 2 performs software overrides of the TCM to assist in problem isolation durin g dia gnostics.

1–2 Solenoid

The TCM commands the 1–2 shift soleno id valve ON and OFF. The Tech 2 1–2 Sol.

parameter should match the commanded state. The Tech 2 Commanded Gear parameter

should correspond with the shift solenoid combination. Refer to 1.4 Electronic Component

Description – Shift Solenoid (SS) Valves in this Section.

When the ignition is ON and the engine is OFF, there are no limits to this control. The

solenoid remains ON until commanded OFF and vice versa. When the output control is

exited, the solenoid state is determined by the TCM.

When the engine is running, the following control limits apply:

• Only sequential gear chan ges are allowed. For example, 1st to 3rd is not allowed. If a

non-sequential gear chang e i s attempted, the message ‘Non-sequential gear

changes not allowed. Gear changes must be’ appears on the Tech 2 display.

• The vehicle speed must be below a calibrated value. If the vehicle speed is too high,

the message ‘Vehicle speed too high’ appears on the Tech 2 display.

• The engine speed must be below a calibrated value. If the engine speed is too high,

the message ‘Engine speed too high’ appea rs on the Tech 2 display.

• Downshifts are allowed only when the vehicle speed is below a calibrated value. If

the vehicle speed is too high, the messa ge ‘Eng. is on and veh. speed too hi for 3-2

or 2–1 downshift’ appears on the Tech 2 display.

• The gear requested may not be greater than the current selected transmission range.

For example, 3rd gear is not allowed if the transmission range is D2. If the gear

requested is greater than the current selected transmissi on range, the message ‘Eng.

running and gear request is greater than the current TR’ appears on the Tech 2

display.

The solenoid remains ON until commande d OF F and vice versa. When the output control

is exited, the solenoid state is determined by the TCM.

2–3 Solenoid

The TCM commands the 2–3 shift soleno id valve ON and OFF. The Tech 2 2–3 Sol.

parameter should match the commanded state. The Tech 2 Commanded Gear parameter

should correspond with the shift solenoid combination. Refer to 1.4 Electronic Component

Description – Shift Solenoid (SS) Valves in this Section.

When the ignition is ON and the engine is OFF, there are no limits to this control. The

solenoid will remain ON until comman ded OFF and vice versa. When the output control is

exited, the solenoid state is determine d by the TCM.

When the engine is running, the following control limits apply:

• Only sequential gear chan ges are allowed. For example, 1st to 3rd is not allowed. If a

non-sequential gear chang e i s attempted, the message ‘Non-sequential gear

changes not allowed. Gear changes must be ’ appears on the Tech 2 displa y.

• The vehicle speed must be below a calibrated value. If the vehicle speed is too high,

the message ‘Vehicle speed too high’ appears on the Tech 2 display.

• The engine speed must be below a calibrated value. If the engine speed is too high,

the message ‘Engine speed too high’ appea rs on the Tech 2 display.

• Downshifts are allowed only when the vehicle speed is below a calibrated value. If

the vehicle speed is too high, the messa ge ‘Eng. is on and veh. speed too hi for 3–2

or 2–1 downshift’ appears on the Tech 2 display.

• The gear requested may not be greater than the current selected transmission range.

For example, 3rd gear is not allowed if the transmission range is D2. If the gear

requested is greater than the current selected transmissi on range, the message ‘Eng.

running and gear request is greater than the current TR’ appears on the Tech 2

display.

The solenoid remains ON until commande d OF F and vice versa. When the output control

is exited, the solenoid state is determined by the TCM.

Automatic Transmission – 5L40-E – Electrical Diagnosis 7E2 – 54

7E2 – 54

4–5 Solenoid

The TCM commands the 4–5 shift soleno id valve ON and OFF. The Tech 2 4–5 Sol.