SECTION 3 - DIAGNOSIS
CAUTION:
This vehicle will be equipped with a Supplemental Restraint System (SRS). A SRS will
consist of either seat belt pre-tensioners and a driver's side air bag, or seat belt pre-
tensioners and a driver's and front passenger's side air bags. Refer to CAUTIONS,
Section 12M, before performing any service operation on, or around any SRS
components, the steering mechanism or wiring. Failure to follow the CAUTIONS
could result in SRS deployment, resu lting in possible perso nal in jury or u nnecessary
SRS system repairs.
3.1 PREREQUISITES TO DIAGNOSIS AND TROUBLESHOOTING
PRELIMINARY SYSTEM REQUIREMENTS
The prerequisites before proceeding with system checks are:
• Ensure that sound earth connections are available for all functioning components, particularly at the body earth
connection (fender panel inner stud, adjacent to the battery).
• Ensure the battery is in good condition and adequately charged (above 12.5 volts) before carrying out any
electrical checks.
SAFETY REQUIREMENTS
Disconnect the battery when carrying out work which
involves the risk of an electrical short circuit.
Do not touch mechanical components during
function checks, to avoid the risk of a hand being
caught in the mechanism.
CHECKING EQUIPMENT
• TECH 2 scan tool.
• A digital multimeter, with a minimum 10 Megohm impedance MUST be used when undertaking any electrical
checks on these systems.
Exercise care when taking readings from wiring harness connectors. It is preferred that the back probing method
with individual connectors is employed wherever possible, to avoid terminal damage and subsequent connection
failure.
When carrying out wiring checks as directed to by the diagnostic charts, rather than probe terminals and connectors
with incorrect sized multimeter connections, use the adaptors contained in connector test adaptor kit KM-609. This
will prevent any possibility of spreading or damaging wiring harness terminals.
IMPORTANT:
ENSURE THAT THE IGNITION IS TURNED OFF AND THE BATTERY EARTH LEAD IS DISCONNECTED
BEFORE ANY TEST THAT REQUIRES DISCONNECTION OR RECONNECTION OF ANY OF THE BCM
CONNECTORS.
When checking the complete system, the exact order of the test steps should be observed.
If the required nominal value is not achieved in any stage, then the problem must be rectified before proceeding
further.
Unless the multimeter being used has an auto ranging function, check that the correct range, as specified, is
selected before the test is carried out.
Testing of the system will involve gaining access to specific wiring harness connectors. For the location of these
connectors, refer to Section 4 WIRING DIAGRA MS or Section 12N FUSES AND WIRING HARNESSES.
Techline
3.2 GENERAL INFORMATION
The procedures outlined in the LPG VEHICLE PRELIMINARY DIAGNOSTIC CHART MUST be carried out first
whenever diagnosing a problem in a LPG vehicle.
The LPG system is designed to operate in LPG mode when LPG has been selected via the fuel mode switch. When
diagnosing the LPG system, unless otherwise directed. Ensure that the LPG mode has been selected, there is LPG
in the LPG cylinder and the manual service valve is turned 'ON'.
When LPG has been selected via the fuel mode switch the PCM will operate in the LPG mode if the operating
parameters sensed by the PCM permit the switching to the LPG mode.
Before any diagnostic procedures are carried out on the LPG system you must first confirm that the vehicle
operates on petrol without any problems and there are NO DIAGNOSTIC TROUBLE CODES stored in the PCM
memory. This can be achieved by following the LPG VEHICLE PRELIMINARY DIAGNOSTIC CHART in this
Section.
After the LPG vehicle preliminary diagnostic procedure has been carried out, an
ON-BOARD DIAGNOSTIC SYSTEM CHECK as described in Section 6C1 must be performed and any diagnostic
trouble code that has been logged in the PCM memory must be rectified and all diagnostic trouble codes cleared
before you confirm any problem with the LPG system.
When carrying out the diagnostic procedures refer to Section 4 WIRING DIAGRAMS.
3.3 LPG VEHICLE PRELIMINARY DIAGNOSIS
TEST DESCRIPTION
The numbers below refer to step numbers in the following diagnostic chart.
1. If the Check Powertrain Lamp illuminates the PCM is being powered up. If the Check Powertrain Lamp does
not illuminate you should refer to the ON-BOARD DIAGNOSTIC SYSTEM CHECK, in Section 6C1.
2. Ensures TECH 2 is functioning correctly.
3. Checks if TECH 2 can communicate with the PCM. If Tech 2 cannot communicate with the PCM you should
refer to PCM diagnostics.
4. Checks if the PCM can operate in the LPG mode.
5. Checks if the LPG switch is operating correctly.
6. Checks the operation of the LPG lamp.
7. Checks if the engine will operate on petrol.
8. Checks if the engine will crank when LPG has been selected.
9. Checks if the engine will run when LPG has been selected.
10. If the engine backfires when operating on LPG, go to the ENGINE BACK FIRES ON LPG diagnostic chart in
this Section.
11. If the engine lacks power is sluggish or has poor performance, refer Diagnostic Chart
3.10 POOR PERFORMANCE, SLUGGISH OR POOR FUEL CONSUMPTION WHEN OPERATING ON LPG
in this Section.
12. If the fuel gauge does not operate correctly on when petrol or LPG has been selected via the fuel mode switch,
refer Diagnostic Chart 3.12 FUEL GAUGE DOES NOT OPERATE in this Section.
STEP ACTION YES NO
1. 1. Turn ignition on.
2. Does the Check Powertrain
Lamp illuminate?
Go to Step 2. Refer Section 6C1,ON-
BOARD DIAGNOSTIC
SYSTEM CHECK.
2. 1. Turn ignition off.
2. Install TECH 2 to DLC.
3. Turn ignition ON.
4. Push power button on TECH 2.
5. Does TECH 2 power up (screen
will illuminate display TECH 2)?
Go to Step 3. Refer TECH 2
DIAGNOSIS, Section 0C
TECH 2.
3. 1. With TECH 2 still connected and
ignition on, press the ENTER
key then select Diagnostics / (V)
1997 / VT Commodore / Engine /
V6 LPG, follow the instructions
on the Tech 2 screen.
2. Does TECH 2 display PCM
system identification information
(PROM ID)?
Go to Step 4. Refer Section 6C1, ON-
BOARD DIAGNOSTIC
SYSTEM CHECK.
4. 1. With TECH 2 still connected and
ignition on, select / F2: Data
Display / F0: All Data / Scroll to
LPG Fuel Enabled.
2. Does TECH 2 display LPG Fuel
Enabled YES?
Go to Step 5. Refer 3.4 DOES NOT
OPERATE ON LPG, in
this Section.
STEP ACTION YES NO
5. 1. With TECH 2 still connected,
scroll to Fuel.
2. Select LPG via the fuel mode
switch.
3. Does TECH 2 display Fuel
change from Petrol to LPG?
Go to Step 6. Refer 3.5 FUEL MODE
SWITCH DOES NOT
OPERATE, in this
Section.
6. 1. Ignition on, select LPG via the
fuel mode switch.
2. Does the LPG lamp illuminate?
Go to Step 7. Refer 3.6 LPG LAMP
DOES NOT OPERATE in
this Section.
7. 1. Select Petrol via the fuel mode
switch.
2. Will the engine crank and start
immediately the key is turned
from off to start (no delay)?
Go to Step 8. Refer ON-BOARD
DIAGNOSTIC SYSTEM
CHECK, Section 6C1.
8. 1. Select LPG via the fuel mode
switch.
2. Will the engine crank
immediately the key is turned
from off to start (no delay)?
Go to Step 9. Refer 3.7 ENGINE DOES
NOT CRANK in this
Section.
9. 1. Does engine crank and run on
LPG? Go to Step 10. Refer 3.8 ENGINE
CRANKS DOES NOT
START ON LPG in this
Section.
10. 1. Does engine backfire when
operated on LPG? Refer Diagnostic
Chart 3.6
ENGINE
BACKFIRES ON
LPG in this
Section.
Go to Step 11.
11. 1. Does engine lack power,
sluggish or have poor
performance when operating on
LPG?
Refer Diagnostic
Chart 3.7 POOR
PERFORMANCE
, SLUGGI SH OR
POOR FUEL
CONSUMPTION
WHEN
OPERATING ON
LPG in this
Section.
Go to step 12
12. 1. Does fuel gauge operate
correctly? Refer Diagnostic
Chart 3.12 FUEL
GAUGE DOES
NOT OPERATE
in this Section.
3.4 DOES NOT OPERATE ON LPG
TEST DESCRIPTION
The numbers below refer to step numbers in the following diagnostic chart.
1. The LPG VEHICLE PRELIMINARY DIAGNOSIS CHECK must be the first step when diagnosing any LPG
system problem.
2. The PCM will not operate in the LPG mode if it is fitted with the incorrect PROM. Refer to the latest technical
publications for the correct PROM application.
3. When the ignition is turned on battery voltage is applied to terminal E11 of the PCM. This enables the PCM to
operate in either the Petrol or LPG mode. If battery voltage is not applied to PCM terminal E11 the PCM will
only operate in the Petrol mode.
4. This test confirms that the PCM connector terminal retention is not causing the problem. The terminal retention
should always be checked before a PCM is replaced.
STEP ACTION YES NO
1. 1. Has an LPG VEHICLE
PRELIMINARY DIAGNOSIS
CHECK been performed.
Go to step 2 Perform an LPG
VEHICLE PRELIMINARY
DIAGNOSIS CHECK.
2. 1. Is the PCM fitted with the correct
LPG PROM? (refer 2.19 PROM
in Section 2).
Go to step 3. Install the correct LPG
PROM.
Verify repair.
3. 1. Ignition on.
2. Check for voltage at PCM
terminal E11 connector YB194
circuit 39 pink wire.
3. Is battery voltage present?
Go to step 4. Repair open in circuit 39
between fuse F14 and
PCM terminal E11.
Verify repair.
4. 1. Check PCM connector terminal
retention.
If retention OK replace PCM.
2. Is terminal retention OK?
Replace PCM.
Verify repair. Repair terminals.
Verify repair.
3.5 FUEL MODE SWITCH DOES NOT OPERATE
TEST DESCRIPTION
The numbers below refer to step numbers in the following diagnostic chart.
1. The LPG VEHICLE PRELIMINARY DIAGNOSIS CHECK must be the first step when diagnosing any LPG
system problem.
2. Tests operation of fuel mode switch.
3. Checks for voltage at the fuel mode switch. If voltage is not present, circuit 39 is open between the fuel mode
switch and fuse F14. If voltage is present there is an open circuit between the fuel mode switch and PCM
terminal A9.
4. This test check for an open in the fuel mode switch circuit 936.
5. This test confirms that the PCM connector terminal retention is not causing the problem. The terminal retention
should always be checked before a PCM is replaced.
STEP ACTION YES NO
1. 1. Has an LPG VEHICLE
PRELIMINARY DIAGNOSIS
CHECK been performed.
Go to step 2 Perform an LPG
VEHICLE PRELIMINARY
DIAGNOSIS CHECK.
2. 1. Test fuel mode switch.
Refer 2.22 FUEL MODE
SWITCH - TEST is Section 2.
2. Is the fuel mode switch OK.
Go to step 3. Replace fuel mode
switch.
3. 1. Ignition on.
2. Check for voltage at the fuel
mode switch connector YB67
circuit 39 (Pink/Black wire).
3. Is battery voltage present?
Go to step 4. Repair open in circuit 39
between fuse F14 and
fuel mode switch.
4. 1. Check for open in circuit 936
(Blue/Orange wire) between fuel
mode switch and PCM terminal
A9.
2. Is circuit open?
Repair open in
circuit 936
between fuel
mode switch and
PCM terminal A9.
Go to step 5.
5. 1. Check PCM connector terminal
retention.
2. Is terminal retention OK.
Replace PCM.
Verify repair. Repair terminals.
Verify repair.
3.6 LPG LAMP DOES NOT OPERATE
TEST DESCRIPTION
The numbers below refer to step numbers in the following diagnostic chart.
1. The LPG VEHICLE PRELIMINARY DIAGNOSIS CHECK must be the first step when diagnosing any LPG
system problem.
2. Tests the operation of the LPG lamp using TECH 2 to command the lamp on and off.
3. This step determines if the lamp bulb or socket is defective.
4. This step checks if the PCM is commanding the instrument to turn on the LPG lamp. If the PCM is
commanding the instrument to turn on the LPG lamp and it does not the instrument is defective. If the PCM is
not commanding the instrument to turn on the LPG lamp then the PCM if defective.
STEP ACTION YES NO
1. 1. Has an LPG VEHICLE
PRELIMINARY DIAGNOSIS
CHECK been performed.
Go to step 2 Perform an LPG
VEHICLE PRELIMINARY
DIAGNOSIS CHECK.
2. 1. Install TECH 2 to DLC.
2. Select Body / Instruments /
Miscellaneous Tests / Lamps /
LPG In Use Lamp
3. Command LPG In Use Lamp on
and off.
4. Does the LPG Lamp turn on and
off when commanded?
Go to Step 4. Go to step 3.
3. 1. Remove Instrument Cluster,
refer Section 12C
INSTRUMENTS, WIPERS /
WASHERS AND HORNS.
2. Remove LPG lamp bulb and
socket from instrument cluster
and check bulb and socket
condition.
3. Is bulb and socket OK?
Replace
instrument
cluster, refer to
Section 12C
INSTRUMENTS,
WIPERS /
WASHERS AND
HORNS.
Replace bulb and/or
socket.
Verify Repair.
4. 1. With TECH 2 still connected
select Engine / V6 LPG / F0:
Normal Mode.
2. Scroll to Fuel Type.
3. Does the TECH 2 display LPG,
when LPG is selected via the
fuel mode switch.
Replace
instrument
cluster, refer to
Section 12C
INSTRUMENTS,
WIPERS /
WASHERS AND
HORNS.
Replace PCM refer to
Section 6C1-3
SERVICE OPERATIONS
- V6 ENGINE.
3.7 ENGINE DOE S NOT CRANK
TEST DESCRIPTION
The numbers below refer to step numbers in the following diagnostic chart.
1. The LPG VEHICLE PRELIMINARY DIAGNOSIS CHECK must be the first step when diagnosing any LPG
system problem.
2. The Theft Deterrent System must be disarmed before the engine will crank. If the Theft Deterrent System
cannot be disarmed, refer to Section 12J1, THEFT DETERRENT DIAGNOSTICS for vehicles fitted with Low
Series BCM’s or Section 12J2, THEFT DETERRENT DIAGNOSTICS for vehicles fitted with High Series
BCM’s.
3. When PETROL is selected the engine should crank immediately the ignition switch is turned from off to start. If
the engine does not crank immediately, then refer to Section 6C1, ON-BOARD DIAGNOSTIC SYSTEM
CHECK.
4. When LPG is selected The engine should crank immediately the ignition Switch is turned from off to start. If the
engine cranks immediately system is operating correctly.
5. When LPG is selected the PCM will prevent the engine from cranking if the PCM determines the throttle is
open more than 7%. This tests uses TECH 2 to monitor the Throttle Position Sensor operation.
STEP ACTION YES NO
1. 1. Has an LPG VEHICLE
PRELIMINARY DIAGNOSIS
CHECK been performed.
Go to step 2 Perform an LPG
VEHICLE PRELIMINARY
DIAGNOSIS CHECK.
2. 1. Disarm theft deterrent system
(LED not flashing).
2. Ignition “OFF”.
3. Is theft deterrent system
disarmed?
Go to Step 3. Refer Section
12J1 Low Series BCM or
12J2 High Series BCM.
3. 1. Ignition on, Select Petrol via the
fuel mode switch.
2. Turn ignition switch to “START”
for a maximum of five seconds
or until engine starts to crank.
3. Does engine crank immediately
(less than one second)?
Go to Step 4. Refer Section 6C1, ON-
BOARD DIAGNOSTIC
SYSTEM CHECK.
4. 1. Ignition on select LPG via the
fuel mode switch.
2. Turn ignition switch to “START”
for a maximum of five seconds
or until engine starts to crank.
3. Does engine crank immediately
(less than one second)?
System operating
correctly.
Check for
intermittent
connections.
Go to Step 5.
5. 1. Turn ignition off.
2. Install TECH 2 to DLC.
3. Turn ignition ON.
4. Push power button on TECH 2.
5. Select ENGINE / ENGINE TYPE
V6 LPG / Data List / All Data.
6. Scroll to Throttle Position
Sensor.
7. Is Throttle Position Sensor
displaying 0%?
Refer
Section 6C1,
ON-BOARD
DIAGNOSTIC
SYSTEM
CHECK.
Refer Chart A-6.2 TP
SENSOR OUTPUT
CHECK, Section 6C1-2A.
3.8 ENGINE CRANKS BUT WILL NOT START ON LPG (1)
TEST DESCRIPTION
The numbers below refer to step numbers in the following diagnostic chart.
1. The LPG VEHICLE PRELIMINARY DIAGNOSIS CHECK must be the first step when diagnosing any LPG
system problem.
2. These initial checks are designed to verify that the engine is capable of operating on LPG.
3. Voltage is supplied to the LPG lockoff from the smart unit when the ignition is first turned on and when the
engine is cranking or running. If voltage is not present at these times the lockoff will not be energised and LPG
will not flow to the converter.
4. This test confirms correct converter operation. Incorrect converter pressures can cause the engine not to start.
5. This test determines if the ADP is causing the no start condition.
6. Vacuum leaks or blockages can cause a variety of system operating problems all hoses and vacuum lines
should be checked.
7. This tests confirms correct mixer operation.
8. This tests confirms correct ADP set up.
STEP ACTION YES NO
1. 1. Has an LPG VEHICLE
PRELIMINARY DIAGNOSIS
CHECK been performed.
Go to step 2. Perform an LPG
VEHICLE PRELIMINARY
DIAGNOSIS CHECK.
2. INITIAL CHECKS:
1. Has LPG been selected via the
fuel mode switch?
2. Is correct LPG PROM installed in
the PCM?
3. Is the manual service valve
open?
4. Is there any LPG present in the
LPG cylinder, check contents
gauge?
If yes to all, go to
Step 3. Repair any faults.
Recheck starting on LPG.
3. 1. Check for voltage at LPG lockoff
connector YE2 circuit 965
(Blue/Yellow wire).
2. Is voltage above 9 volts for 3
seconds when the ignition is first
turned on or while the engine is
cranking?
Go to Step 4. Go to Diagnostic Chart
ENGINE CRANKS BUT
WILL NOT START ON
LPG (PART 2) in this
Section.
4. 1. Test for presents of LPG in
system by checking converter
pressures. (Refer 2.15
CONVERTER in Section 2).
2. Are converter pressures OK?
Go to Step 5. Go to Diagnostic Chart
ENGINE CRANKS BUT
WILL NOT START ON
LPG (PART 3) in this
Section.
Techline
STEP ACTION YES NO
5. 1. Ignition on, select Petrol via the
fuel mode switch.
2. Start engine and bring to 2000
RPM.
3. Select the LPG mode via the fuel
mode switch.
4. Does the engine continue to
run?
Set up ADP and
adjust LPG
mixture. Refer
2.23 ADP
SET-UP
PROCEDURE in
Section 2.
Recheck starting
on LPG.
Go to Step 6.
6. 1. Check for vacuum leaks in
vacuum or vapour feed lines
between mixer and converter, or
a blocked balance line, FCV or
Regulator Check Valve.
2. Are there any leaks or
blockages?
Repair vacuum
leaks or
blockages.
Recheck starting
on LPG.
Go to Step 7.
7. 1. Test mixer operation (refer 2.18
MIXER in Section 2).
2. Is mixer operating correctly ?
Go to Step 8. Check and repair any air
leaks between mixer and
throttle body, if no leaks
overhaul mixer.
Refer 2.18 MIXER
in Section 2.
Recheck starting on LPG.
8. 1. Set up ADP and adjust LPG
mixture (refer 2.23 ADP SET-UP
PROCEDURE in Section 2) and
recheck starting on LPG.
2. Does engine start on LPG?
System OK. Go to Diagnostic Chart
ENGINE CRANKS BUT
WILL NOT START ON
LPG (PART 2).
ENGINE CRANKS BUT WILL NOT START ON LPG (2)
TEST DESCRIPTION
1. The smart unit and the ADP receive voltage from the LPG relay via fuse F9, if fuse F9 is blown the smart unit
will not operate.
2. This test checks the continuity of the smart unit earth circuit if the smart unit does not have a good earth then it
will not operate.
3. This test checks to see if the smart unit is supplying voltage to the LPG lockoff. If voltage is present at the
smart unit then the circuit between the smart unit and the LPG lockoff is open or shorted to earth.
NOTE:
The smart unit has a current protection device on this circuit, if circuit 965 is shorted to earth the smart unit will
shutdown. The ignition must be cy cled from on to off to reset the smart unit.
4. With the ignition on and LPG selected battery voltage should be supplied to circuit 1035 (Pink/Green wire)
when the LPG relay is energised by the PCM.
5. This test checks if the LPG relay is operating correctly .
6. With Petrol selected via the fuel mode switch, battery voltage should be present at PCM terminal E1 circuit 935
(Red/Yellow wire).
7. When LPG is selected via the fuel mode switch the PCM earths terminal E1 causing circuit E1 circuit 935
(Red/Yellow wire) to be pulled low, less than 0.2 volts.
8. When operating in the LPG mode, the PCM pulses the 5 volt pull up in the smart unit to earth via circuit 937 at
a 50% duty cycle. Therefore the voltage at PCM terminal E5 should be 2 to 3 volts when the ignition is first
turned on or when the engine is cranking.
9. This test checks the continuity of circuit 937(White/Green wire).
10. This test checks if circuit 937(White/Green wire) is shorted to earth.
STEP ACTION YES NO
1. 1. Is fuse F9 OK? Go to Step 2. Replace fuse. Check for
short in LPG lockoff
circuit 965. Recheck
starting on LPG
2. 1. Check continuity of smart unit
earth circuit 750 (Black/Red
wire) between smart unit
connector YR50 and a known
good earth.
2. Is there continuity?
Go to step 3. Repair open in circuit 750
(Black/Red wire).
Recheck starting on LPG.
3. 1. Ignition ON, LPG selected.
2. Check voltage at smart unit
connector YR50 circuit 965
(Blue/Yellow wire).
3. Is voltage above 9 volts for three
seconds when the ignition is first
turned on or while the engine is
being cranked?
Repair open or
short to earth in
LPG lockoff
circuit 965
between smart
unit and lockoff.
Recheck starting
on LPG.
Go to Step 4.
4. 1. Ignition ON, LPG selected.
2. Check for voltage at smart unit
connector YR50 circuit 1035
(Pink/Green wire).
3. Is battery voltage present for
three seconds when ignition first
switched on or while the engine
is being cranked?
Go to Step 8. Got to Step 5.
5. 1. Is LPG relay OK.
Refer 2.21 in Section 2 for LPG
relay location.
Go to step 6. Replace LPG Relay.
Recheck starting on LPG.
6. 1. Ignition ON, Petrol Mode
selected via the fuel mode
switch.
2. Check voltage at PCM terminal
E1 circuit 935 (Red/Yellow wire).
3. Is battery voltage present?
Go to step 7. Repair open in circuit 935
(Red/Yellow wire)
between the LPG relay
and PCM.
Recheck starting on LPG.
STEP ACTION YES NO
7. 1. Ignition ON, Petrol Mode
selected via the fuel mode
switch.
2. Check voltage at PCM terminal
E1 circuit 935 (Red/Yellow wire).
3. Does voltage drop from battery
voltage to less than 0.2 volts for
3 seconds when LPG is selected
via the fuel mode switch?
Go to step 8. Check PCM connector
terminal retention, if OK,
Replace PCM.
Recheck starting on LPG.
8. 1. With LPG selected via the fuel
mode switch.
2. Check voltage at PCM terminal
E5 circuit 937 (White/Green
wire).
3. Turn the ignition on, is voltage
approximately 5 volts for three
seconds when the ignition is first
turned on or when the engine is
cranking?
Check smart unit
connector
terminal retention
if OK, replace
Smart Unit.
Verify repair.
Go to step 9.
9. 1. Check continuity of circuit 937
(White/Green wire) between
smart unit connector YR50 and
PCM connector YB194 terminal
E5.
2. Is there continuity?
Go to step 10. Repair open in circuit 937
(White/Green wire).
Verify repair.
10. 1. Check for a short to earth in
circuit 937 (White/Green wire)
between smart unit connector
YR50 and PCM connector
YB194 terminal E5.
2. Is there a short to earth?
Repair short to
earth in
circuit 937
(White/Green
wire).
Verify repair.
Check PCM connector
terminal retention, if OK,
Replace PCM.
Recheck starting on LPG.
ENGINE CRANKS BUT WILL NOT START ON LPG (3)
TEST DESCRIPTION
1. Low primary converter pressure can be cause by low supply pressure or a faulty converter.
2. If the primary converter pressure is too high the converter will have to be overhauled.
3. If the primary converter pressure is within specification but the secondary converter is out of specification the
converter will have to be overhauled.
4. This test checks if the solenoid valve is restricting the flow of LPG.
5. This tests check the flow of LPG from the LPG cylinder to the LPG lockoff.
6. This tests determines if the LPG lockoff or the converter is causing the problem.
7. This tests check if the service line is blocked. If the service line is not blocked then the manual service valve or
the LPG cylinder pick up must be blocked.
STEP ACTION YES NO
1. 1. Is primary converter pressure
below specification? Go to Step 4. Got to Step 2.
2. 1. Is primary converter pressure
above specification? Repair converter,
refer 2.15
CONVERTER in
Section 2.
Recheck starting
on LPG.
Go to Step 3.
3. 1. If primary converter pressure is
within specification, is the
secondary converter pressure
out of specification?
Repair converter,
refer 2.15
CONVERTER in
Section 2.
Recheck starting
on LPG.
Go to step 4.
4. 1. Ignition off.
2. Close manual service valve.
3. Remove the solenoid valve from
the manual service valve
assembly and reinstall solenoid
sleeve, refer 2.8 SMART UNIT
AND SOLENOID VALVE in
Section 2.
4. Does engine start and run on
LPG?
Replace Smart
unit and solenoid
valve.
Recheck starting
on LPG.
Go to Step 5.
5. 1. Ignition off.
2. Close manual service valve.
3. With the solenoid valve still
removed from the manual
service valve assembly.
4. Disconnect the front service line
at the LPG lockoff.
5. In accordance with AS-1425,
have a second technician open
the manual service valve (slowly
so that the excess flow valve
doesn’t shut LPG flow off, if a
click is herd at the manual
service valve, the excess flow
valve has closed).
6. Does LPG flow from the front
service line?
Go to Step 6. Go to Step 7.
6. 1. Test LPG lockoff (refer 2.14 LPG
LOCKOFF in Section 2).
2. Is LPG lockoff OK?
Repair converter,
refer 2.14
CONVERTER in
Section 2.
Recheck starting
on LPG.
Repair LPG lockoff, refer
2.14 LPG LOCKOFF
in Section 2.
Recheck starting on LPG.
7. 1. Disconnect rear service line at
manual service valve.
2. With front service line still
disconnected, blow air through
service line to check for
blockages
3. Does air flow through service
line?
Check for manual
service valve or
LPG cylinder fuel
pick-up blockage
or fault. Repair or
replace blocked
or damaged
components.
Recheck starting
on LPG.
Check for damaged or
blocked service lines.
Repair or replace blocked
or damaged components.
Recheck starting on LPG.
3.9 ENGINE BACKFIRES ON LPG
TEST DESCRIPTION
The numbers below refer to step numbers in the following diagnostic chart.
NOTE:
Whenever a engine backfire has occurred the complete intake system including the mixer should be checked for
damage.
1. The LPG VEHICLE PRELIMINARY DIAGNOSIS CHECK must be the first step when diagnosing any LPG
system problem.
2. An ON BOARD DIAGNOSTIC SYSTEM CHECK should be performed to confirm that a problem with the
Powertrain Management system is not causing the engine to backfire when operating on LPG?
3-7 An ignition system that is not operating at it’s full potential can cause an engine to backfire when operating on
LPG. Ignition leads that operate quite well when operating on petrol, can cause problems when operating on
LPG. Therefore, all ignition system components must be at here optimum when operating on LPG.
8. Vacuum leaks or blocked vacuum lines can cause incorrect system operation, causing engine backfire.
9. Incorrect mixer operation can cause incorrect air/fuel ratios. Incorrect air/fuel ratios can cause engine backfire.
10. Incorrect ADP set-up can cause incorrect system operation, causing engine backfire.
11. Incorrect converter operation can cause incorrect air/fuel ratios. Incorrect air/fuel ratios can cause engine
backfire.
12. This test will confirm correct Regulator Check Valve (RCV) operation, incorrect RCV operation can cause slow
converter response causing engine backfire.
13. Engine mechanical condition can cause engine operating problems that do not effect the engine when
operating on petrol. The engine must be in optimum operating condition to prevent the engine backfiring when
operating on LPG.
STEP ACTION YES NO
1. 1. Has an LPG VEHICLE
PRELIMINARY DIAGNOSIS
CHECK been performed.
Go to step 2 Perform an LPG
VEHICLE PRELIMINARY
DIAGNOSIS CHECK.
2. 1. Has an ON BOARD
DIAGNOSTIC SYSTEM CHECK
been performed?
Refer ON-BOARD DIAGNOSTIC
SYSTEM CHECK, Section 6C1.
Go to Step 3. Perform ON-BOARD
DIAGNOSTIC SYSTEM
CHECK., Refer Section
6C1.
Recheck for engine
backfire.
3. 1. Check spark plug leads for
tracking or cracks in insulation
and resistance (refer Section
6D1).
2. Are the spark plugs leads OK?
Go to Step 4. Replace spark plug leads.
Recheck for engine
backfire.
4. 1. Remove and inspect spark plugs
for fowling.
2. Are the spark plugs OK?
Go to Step 5. Replace spark plugs.
Recheck for engine
backfire.
5. 1. Re-gap spark plugs to minimum
specification.
2. Have spark plugs been re-gaped
to minimum specification?
Go to Step 6. Re-gap spark plugs to
minimum specification
Recheck for engine
backfire.
6. 1. Check coil resistance (refer
Section 6D1).
2. Is the ignition coil resistance
within specification?
Go to Step 7. Replace faulty ignition
coil.
Recheck for engine
backfire.
STEP ACTION YES NO
7. 1. Check PCM, DIS and Crank
Angle Sensor terminal retention.
2. Is terminal retention OK?
Go to Step 8. Resize terminals.
Recheck for engine
backfire.
8. 1. Check for vacuum leaks in
vacuum or vapour feed lines
between mixer and converter, or
a blocked balance line, FCV or
Regulator Check Valve.
2. Are there any leaks or
blockages?
Repair vacuum
leaks or
blockages.
Recheck for
engine backfire.
Go to Step 9.
9. 1. Test mixer operation (refer 2.18
MIXER in Section 2).
2. Is mixer operating correctly ?
Go to Step 10. Overhaul mixer. Refer
2.18 MIXER in Section 2.
Recheck for engine
backfire.
10. 1. Is the ADP set-up correct?
(refer 2.23 ADP SET-UP
PROCEDURE in Section 2).
Go to Step 11. Carry out ADP set-up
procedure.
Recheck for engine
backfire.
11 1. Test converter pressures. (Refer
2.15 CONVERTER in Section 2).
2. Are converter pressures OK?
Go to Step 12. Overhaul converter.
(Refer 2.15
CONVERTER in Section
2).
12. 1. Test Regulator Check Valve
operation (refer 2.16
REGULATOR CHECK VALVE in
Section 2).
2. Is Regulator Check Valve
operating correctly?
Go to Step 13. Replace Regulator Check
Valve. (refer 2.16
REGULATOR CHECK
VALVE in Section 2)
Recheck for engine
backfire.
13. 1. Check engine mechanical
condition by checking
compression, valve timing,
intake and exhaust valves and
manifolds for casting flash.
2. Is the engine mechanical
condition OK?
Check for
incorrectly routed
harnesses,
ignition leads or
non genuine
accessories.
Repair any faults.
Recheck for engine
backfire.
3.10 POOR PERFORMANCE, FLAT SPOTTING, SLUGGISH OR POOR FUEL
CONSUMPTION WHEN OPERATING ON LPG
NOTE:
Because of the nature of LPG, a minimal loss of power may be experienced under heavy acceleration, this
is expected and quite normal.
TEST DESCRIPTION
The numbers below refer to step numbers in the following diagnostic chart.
1. The LPG VEHICLE PRELIMINARY DIAGNOSIS CHECK must be the first step when diagnosing any LPG
system problem.
2. An ON BOARD DIAGNOSTIC SYSTEM CHECK should be performed to confirm that a problem with the
Powertrain Management system is not causing the engine to backfire when operating on LPG?
3. These symptoms checks this the most common causes of engine drivability problems.
4. Incorrect ADP operation can cause incorrect air/fuel ratios.
5. Incorrectly tensioned air valve to diaphragm attaching screws can cause incorrect mixer operation.
6. Correct mixer operation is required so that the correct air/fuel ratio is achieved.
7. A regulator check valve that is blocked or opening at the wrong vacuum can cause incorrect converter
operation.
8. The converter is one of the key components in the control of the delivery of LPG. Incorrect converter operation
can cause rich or lean mixtures.
STEP ACTION YES NO
1. 1. Has an LPG VEHICLE
PRELIMINARY DIAGNOSIS
CHECK been performed.
Go to step 2 Perform an LPG
VEHICLE PRELIMINARY
DIAGNOSIS CHECK.
2. 1. Has an ON BOARD
DIAGNOSTIC SYSTEM CHECK
been performed?
Refer ON-BOARD DIAGNOSTIC
SYSTEM CHECK, Section 6C1.
Go to Step 3. Perform ON-BOARD
DIAGNOSTIC SYSTEM
CHECK. Refer
Section 6C1.
Recheck performance.
3. 1. Carry out SYMPTOMS CHECK
(refer Section, 6C1-2B).
2. Are all checks OK?
Go to Step 4. Repair any faults.
Recheck performance.
4. 1. Is the ADP set-up correctly?
(refer 2.23 ADP SET-UP
PROCEDURE in Section 2)
Go to Step 5. Carry out ADP set-up
procedure.
Recheck performance.
5. 1. Check air valve to diaphragm
attaching screws for correct
torque.
(refer 2.18 MIXER in Section 2)
2. Are screws tightened to the
correct torque?
Go to Step 6. Tension Screws to the
correct torque
specification. Refer 2.18
MIXER in Section 2.
Recheck performance.
6. 1. Test mixer operation (refer 2.18
MIXER in Section 2).
2. Is mixer operating correctly?
Go to Step 7. Overhaul mixer. Refer
2.18 MIXER in Section 2.
Recheck performance.
7. 1. Test Regulator Check Valve
operation (refer 2.16
REGULATOR CHECK VALVE).
2. Is Regulator Check Valve
operating correctly?
Go to Step 8. Replace Regulator Check
Valve.
Recheck performance.
8. 1. Test converter operation (refer
2.16 CONVERTER).
2. Is converter operating correctly?
Repair converter, refer
2.16 CONVERTER.
Recheck performance.
3.11 FUEL CONTROL VALVE DOES NOT OPERATE
TEST DESCRIPTION
The numbers below refer to step numbers in the following diagnostic chart.
1. The LPG VEHICLE PRELIMINARY DIAGNOSIS CHECK must be the first step when diagnosing any LPG
system problem.
2. These initial checks are designed to verify that the engine is capable of operating on LPG.
3. If the FCV can be heard operating the ADP is being powered up and pulsing the FCV.
4. This test checks that the ADP is pulsing the FCV.
5. This test checks if power is being supplied to the FCV.
6. This test checks if the ADP is supplying power to circuit 1061 (Blue/Yellow wire).
7. This test checks the continuity of circuit 1062 Black/Blue wire.
8. This test checks that battery voltage is being supplied from the LPG relay to the ADP via circuit 1035
(Pink/Blue wire).
9. This test checks the continuity of both of the ADP earth circuits.
10. In this test step circuit 1062 (Black/Blue wire) is checked for a short to earth?
11. This test checks the operation of the FCV.
STEP ACTION YES NO
1. 1. Has an LPG VEHICLE
PRELIMINARY DIAGNOSIS
CHECK been performed.
Go to step 2. Perform an LPG
VEHICLE PRELIMINARY
DIAGNOSIS CHECK.
2. INITIAL CHECKS:
1. Has LPG been selected via the
fuel mode switch?
2. Is correct LPG PROM installed in
the PCM.
3. Is fuse F9 OK?
If YES to all,
go to Step 3. Repair any faults.
Verify repair.
3. 1. Ignition ON, LPG selected via
fuel mode switch.
2. Can fuel control valve be heard
operating?
Go to Step 10. Go to step 4
4. 1. Remove connectors from FCV.
2. Ignition ON.
3. Check voltage between FCV
circuits 1061 (Blue/Yellow wire)
and 1062 (Black/Blue wire).
4. Is voltage at least 9 volts for
three seconds when ignition first
switched on?
Go to step 10. Go to Step 5.
5. 1. Remove connectors YE2 from
FCV terminals.
2. Ignition on, LPG selected via fuel
mode switch.
3. Check for voltage between
connector YE2 circuit 1061
(Blue/Yellow wire) and a known
good earth.
4. Is battery voltage present for
three seconds when ignition first
switched on?
Go to Step 7. Go to Step 6.
STEP ACTION YES NO
6. 1. Ignition on LPG selected via fuel
mode switch.
2. Check for voltage at ADP
connector YB122 circuit 1061
(Blue/Yellow wire).
3. Is battery voltage present for
three seconds when ignition first
switched on?
Repair circuit
1061
(Blue/Yellow
wire).
Verify repair.
Go to Step 7.
7. 1. Check continuity of circuit 1062
(Black/Blue wire) between FCV
terminal YE2 and ADP connector
YB122.
2. Is there continuity?
Go to Step 8. Repair open in circuit
1062 (Black/Blue wire)
Verify repair.
8. 1. Ignition ON, LPG selected via
fuel mode switch.
2. Check for voltage at ADP
connector YB122 circuit 1035
(Pink/Blue w ire).
3. Is battery voltage present for
three seconds when ignition first
switched on?
Go to Step 9. Repair open circuit 1035
(Pink/Blue w ire).
Verify repair.
9. 1. Check continuity of ADP earth
circuits 750 (Black/Red wire) and
circuit 751 (Black/Blue wire) from
ADP connector YB122 and a
known good earth.
2. Is there continuity?
Check ADP
connector
terminal retention
if OK,
replace ADP.
Verify repair.
Repair faulty ADP earth
circuit 750
(Black/Red wire) and 751
Black/Blue Wire.
Verify repair.
10. 1. Check for a short to earth in
circuit 1062 (Black/Blue wire).
2. Is circuit 1062 (Black/Blue wire)
shorted to earth?
Repair short to
earth in circuit
1062
(Black/Blue
wire).
Verify repair.
Go to step 11.
11. 1. Test operation of FCV, (refer
2.17 FUEL CONTROL VALVES
in Section 2).
2. If FCV operating correctly?
Perform ADP set
up procedure.
(refer 2.23 FUEL
CONTROL
VALVES in
Section 2).
Verify repair.
Check FCV connector
terminal retention if OK,
replace FCV.
Verify repair.
3.12 FUEL GAUGE DOES NOT OPERATE
TEST DESCRIPTION
The numbers below refer to step numbers in the following diagnostic chart.
1. The LPG VEHICLE PRELIMINARY DIAGNOSIS CHECK must be the first step when diagnosing any LPG
system problem.
2. In this test TECH 2 is used to test the operation of the Instrument fuel gauge.
3. This test confirms correct operation of the cylinder fuel gauge assembly.
4. If the TECH 2 instrument LPG sender signal is displaying 5 volts the LPG sender circuit is open circuited.
5. If the TECH 2 instrument LPG sender signal is displaying 0 volts the LPG sender circuit is short circuited.
6. This test step checks the continuity of the cylinder fuel gauge earth circuit.
7. In this test step circuit 1030 (Yellow wire) is checked for a short to earth.
8. This test step checks the continuity of the LPG sender circuit 1030 between the cylinder fuel gauge and the
instrument assembly.
9. This test checks for a short circuit to earth on circuit 1030.
10. In this test step the cylinder fuel gauge assembly is removed from the LPG cylinder and checked for correct
operation.
CAUTION:
All safety precautions listed in 2.12 CYLINDER FUEL GAUGE ASSEMBLY in Section 2 must be observed.
STEP ACTION YES NO
1. 1. Has an LPG VEHICLE
PRELIMINARY DIAGNOSIS
CHECK been performed.
Go to step 2 Perform an LPG
VEHICLE PRELIMINARY
DIAGNOSIS CHECK.
2. 1. Install TECH 2 to DLC.
2. Select Body / Instruments / F4:
Miscellaneous Tests / F7:
Control Tests / F3: Fuel Gauge
Level
3. Run Fuel Gauge Level test.
4. Does fuel gauge operate
correctly?
Go to Step 3. Replace instrument
cluster, refer to Section
12C INSTRUMENTS,
WIPERS / WASHERS
AND HORNS.
3. 1. Does fuel gauge operate when
petrol is selected via the fuel
mode switch.
Go to step 4. Refer 3. 13 FUEL
GAUGE DOES NOT
OPERATE WHEN
PETROL SELECTED in
this Section.
4. 1. Test operation of cylinder fuel
gauge. (refer 2.12 CYLINDER
FUEL GAUGE ASSEMBLY in
Section 2).
2. Is cylinder fuel gauge operating
correctly?
Go to step 5. Replace cylinder fuel
gauge. (refer 2.12
CYLINDER FUEL
GAUGE ASSEMBLY in
Section 2).
5. 1. Install TECH 2 to DLC select
Body/ Instruments / F2: Data
Display / F0: Instrument.
2. Scroll to LPG Sender Signal.
3. Is the LPG Sensor Signal 5
Volts.
Go to step 7. Go to step 6.
6. 1. In test step 5 is the LPG Sender
Signal 0 Volts? Go to step 7. Go to step 10.
STEP ACTION YES NO
7. 1. Is circuit 1030 (Yellow w ire)
shorted to earth? Repair short to
earth in circuit
1030 (Yellow
wire).
Verify Repair.
Go to step 10.
8. 1. Check continuity of circuit earth
circuit 155, (Black wire) between
connector YR50 and a known
good earth.
2. Is there continuity?
Go to step 9. Repair open in earth
circuit 155,
(Black/Yellow wire).
Verify Repair.
9. 1. Check continuity of circuit 1030,
(Yellow wire) between connector
YR50 and instrument assembly
connector YB66.
2. Is there continuity?
Go to step 10. Repair open in circuit
1030 (Yellow wire).
Verify Repair.
10. 1. Remove cylinder fuel gauge
assembly. (Refer 2.12
CYLINDER FUEL GAUGE
ASSEMBLY in Section 2).
2. Check operation of cylinder fuel
gauge assembly.
(Check for binding, jammed &
smooth operation).
3. Does cylinder fuel gauge
assembly operate correctly?
Check all
connector
terminal
retention.
Monitor TECH 2
Instrument Data
List while
manipulating
wiring harness to
check for an
intermittent
connection.
Replace cylinder fuel
gauge assembly. (refer
2.12 CYLINDER FUEL
GAUGE ASSEMBLY in
Section 2).
Verify repair.
3.13 FUEL GAUGE DOES NOT OPERATE WHEN PETROL SELECTED
TEST DESCRIPTION
The numbers below refer to step numbers in the following diagnostic chart.
1. The LPG VEHICLE PRELIMINARY DIAGNOSIS CHECK must be the first step when diagnosing any LPG
system problem.
2. In this test TECH 2 is used to check the signal from the fuel gauge sender.
3. In this test TECH 2 is used to check circuit 30 (Tan wire), if the fuel gauge sender unit signal is not 0 volts
circuit 30 is open.
4. In this test TECH 2 is used to check circuit 30 (Tan wire), if the fuel gauge sender unit signal is not 5 volts
circuit 30 is shorted to earth.
5. This test confirms correct operation of the fuel gauge sender unit.
6. This test confirms correct fuel gauge sender unit operation.
STEP ACTION YES NO
1. 1. Has an LPG VEHICLE
PRELIMINARY DIAGNOSIS
CHECK been performed.
Go to step 2 Perform an LPG
VEHICLE PRELIMINARY
DIAGNOSIS CHECK.
2. 1. Install TECH 2 to DLC select
Body/ Instruments / F2: Data
Display / F0: Instrument.
2. Scroll to Fuel Gauge Sender
Signal.
3. Is the Fuel Gauge Sensor Signal
5 Volts.
Go to step 3. Go to step 4.
3. 1. With TECH 2 still connected.
2. Disconnect fuel gauge sender
unit connector YR44.
3. Jumper circuit 30 (Tan wire) to a
known good earth.
4. Is the Fuel Gauge Sensor Signal
0 Volts.
Go to step 6. Repair open in circuit
30 (Tan wire).
Verify repair.
4. 1. With TECH 2 still connected.
2. Disconnect fuel gauge sender
unit connector YR44.
3. Is the Fuel Gauge Sensor Signal
5 Volts.
Go to step 5. Repair short to earth in
circuit 30 (Tan wire).
Verify repair.
5. 1. Disconnect connector YR44.
2. Check continuity of fuel gauge
sender unit earth circuit 156
(Black/Blue wire) between
connector YR44 and a known
good earth.
3. Is there continuity?
Go to step 6. Repair open in earth
circuit 156, (Black/Blue
wire).
Verify Repair.
6. 1. Test operation of fuel gauge
sender unit. (refer 2.3 SENDER
UNIT in Section 12C).
2. Is fuel gauge sender unit
operating correctly.
Check all
connector
terminal
retention.
Monitor TECH 2
Instrument Data
List while
manipulating
wiring harness to
check for an
intermittent
connection.
Replace fuel gauge
sender unit. (refer 2.3
FUEL SENDER
ASSEMBLY in Section
8A).
3.14 PCM CONNECTOR TERMINAL VOLTAGES WITH EXPLANATIONS
A - B TERMINAL CONNECTOR
A1 - SYSTEM EARTH
A2 - SYSTEM EARTH
These terminals should have zero volts. They are connected directly to the engine earth.
A3 - PRIMARY SERIAL DATA
This is a serial data circuit used to transmit serial data between the PCM, ABS/ETC, BCM, instruments and the
ECC and Tech 2 when connected to the DLC. The Tech 2 scan tool can "talk" to each of these modules by sending
a message to control module and asking only it to respond. The communication rate is at 8192 baud. The normal
voltage on this circuit is about 3-5 volts, but when the Tech 2 is communicating with a control module, the voltage
will vary and may read about 2.5 volts.
A4 - IGNITION SWITCH INPUT SIGNAL
This is the "turn on" signal to the PCM from the ignition switch circuit. It is not the "power supply" to the PCM, it only
tells the PCM that the ignition switch is "ON." The voltage should equal the battery voltage when the key is in either
the `run' or `crank' position.
A5 - NOT USED
A6 - FUEL PUMP (FP) RELAY CONTROL
Petrol Mode
Turning the ignition on causes the PCM to energise (+12V) the Fuel Pump Relay. If no crankshaft reference input
pulses are received, the PCM turns "OFF" the relay. As soon as the PCM receives crankshaft reference input
pulses, the PCM will turn the Fuel Pump Relay on again.
LPG Mode
The PCM will energise (+12V) the Fuel Pump Relay when starting in the LPG mode, the fuel pump will run for 2
seconds when the ignition is turned to the on position and continue to run when the engine is being cranked, but will
be turned off 5 seconds after the engine has started. The fuel pump will also operate under high load conditions.
This allows for petrol to be injected into the engine when the vehicle goes into the engine valve recession protection
mode.
A7 - THROTTLE POSITION (TP) SENSOR
Reference Voltage
This voltage should always be 5 volts anytime the ignition is "ON." It is a regulated voltage output from the PCM,
and supplies 5 volts to the TP sensor.
A8 - BATTERY VOLTAGE FEED
- HOT AT ALL TIMES -
This supplies the PCM with full-time +12 volts. It stays hot even when the ignition is turned off. It receives its voltage
through the "ENGINE" fuse F25. This PCM terminal could be called the power supply and "MEMORY" terminal.
A9 - FUEL MODE SWITCH
The fuel mode switch is mounted in the centre console and is a momentary type switch. When pressed the switch
supplies 12 volts to PCM terminal A9. The PCM sees this voltage as a request to change over from Petrol to LPG or
from LPG to petrol.
A10 - NOT USED
A11 - NOT USED
A12 - NOT USED
B1 - SYSTEM EARTH
B2 - SYSTEM EARTH
These terminals should have zero volts. They are connected directly to the engine earth.
B3 - A/C REFRIGERANT PRESSURE SENSOR INPUT SIGNAL
The signal that is sent from the pressure transducer to the PCM indicates to the PCM what the A/C pressure is at.
Depending on the A/C pressure, this signal will indicate to the PCM if A/C pressure is to low or to high.
B4 - INTAKE AIR TEMPERATURE (IAT) INPUT SIGNAL
The PCM sends a 5 volt signal voltage to the IAT sensor, which is a temperature - variable-resistor called a
thermistor. The sensor is also connected to earth, and will alter the signal voltage according to incoming air
temperature. As the air temperature increases, the voltage seen on this terminal decreases. At 0 degrees C, the
voltage will be above 4 volts. At normal operating temperature (10 degrees C to 80 degrees C) the voltage will be
less than 4 volts.
B5 - ENGINE COOLANT TEMPERATURE (ECT)INPUT SIGNAL
The PCM sends a 5 volt signal voltage out to the engine coolant temperature sensor, which is a temperature-
variable-resistor called thermistor. The sensor, being also connected to earth, will alter the voltage according to
engine coolant temperature. As the engine coolant temperature increases, the voltage seen on terminal B5
decreases. At 0 degrees C engine coolant temperature the voltage will be above 4 volts. At normal operating
temperature (85 degrees C to 100 degrees C) the voltage will be less than 2 volts.
B6 - TRANSMISSION FLUID TEMPERATURE (TFT) INPUT SIGNAL
- AUTO TRANS ONLY
The PCM sends a 5 volt signal voltage out to the transmission fluid temperature sensor, which is a temperature-
variable-resistor called thermistor. The sensor, being also connected to earth, will alter the voltage according to
transmission fluid temperature. As the fluid temperature increases, the voltage seen on terminal B6 will decrease.
B7 - EGR/A/C PRESSURE SENSOR REFERENCE VOLTAGE
This voltage should always be 5 volts anytime the ignition is "ON." It is a regulated voltage output from the PCM,
and supplies 5 volts to the A/C Pressure Transducer and EGR valve.
B8 - BATTERY VOLTAGE FEED
- HOT AT ALL TIMES -
This supplies the PCM with full-time +12 volts. It stays hot even when the ignition is turned off. It receives its voltage
through the "ENGINE" fuse F25. This PCM terminal could be called the power supply and "MEMORY" terminal.
B9 - NOT USED
B10 - LINEAR EGR VALVE PINTLE POSITION
This voltage is a indication to the PCM the position of the EGR valve pintle position. A low voltage indicates a fully
extended pintle (closed valve). A voltage near 5 volts indicates a retracted pintle (open valve).
B11 - THROTTLE POSITION (TP) SENSOR
The TP sensor input voltage, which follows actual throttle changes, is variable from 0 to 5 volts. Typically the voltage
is less than 1 volt at idle, and 4 to 5 volts at wide-open throttle.
B12 - INJECTOR CIRCUIT VOLTAGE MONITOR INPUT SIGNAL
The injector voltage monitor line is used so that the PCM will know the exact voltage the fuel injectors are operating
at. This voltage signal is used to modify the fuel injector pulse width calculation.
C - D TERMINAL CONNECTOR
C1 - TORQUE CONVERTER CLUTCH ENABLE SOLENOID CONTROL
- AUTO TRANS ONLY
The PCM is used to either open or provide a path to earth for the torque converter solenoid. When the PCM
provides a path to earth, the TCC solenoid is considered ON and voltage should be near 0 volts. The PCM uses
both the TCC enable solenoid and the TCC "PWM" solenoid to control the torque converter clutch. (See TCC PWM
solenoid terminal E1)
C2 - 1 - 2 SHIFT SOLENOID CONTROL
- AUTO TRANS ONLY -
The PCM is used to either open or provide a path to earth for the 1-2 shift solenoid. When the PCM provides a path
to earth, the 1-2 shift solenoid is considered "ON" and the voltage should read 0 volts.
C3 - 2 - 3 SHIFT SOLENOID CONTROL
- AUTO TRANS ONLY
The PCM is used to either open or provide a path to earth for the 2-3 shift solenoid. When the PCM provides a path
to earth, the 2-3 shift solenoid is considered "ON" and the voltage should read 0 volts.
C4 - CANISTER PURGE SOLENOID CONTROL
The PCM operates a normally closed solenoid valve, which controls vacuum to purge the evaporative emissions
storage canister of stored gasoline vapours. The PCM turns "ON" the pulse width modulated control of the purge
solenoid, to control purging of the stored vapours. If the PCM is not energising the purge solenoid, the voltage
measured at this terminal should equal battery voltage. If the PCM is controlling the solenoid, the measured voltage
will be between battery voltage and 0.50 volts.
C5 - VEHICLE SPEED OUTPUT TO SPEEDOMETER
The PCM alternately earths this signal, in pulses, when it receives a vehicle speed signal from the vehicle speed
sensor in the transmission. This pulsing action takes place about 6250 times per kilometer. The speedometer
calculates vehicle speed based on the time between pulses.
C6 - VEHICLE SPEED SENSOR - OUTPUT SHAFT SPEED INPUT SIGNAL HIGH
The transmission has an output shaft speed sensor used by the PCM to calculate vehicle speed, and to help
determine various automatic transmission shifting functions. It is a magnetic inductive sensor that generates an AC
voltage signal sent to the PCM. If measured with the digital AC voltmeter, no voltage will appear until the output
shaft begins turning.
C7 - IDLE AIR CONTROL (IAC)
C8 - IDLE AIR CONTROL (IAC)
C9 - IDLE AIR CONTROL (IAC)
C10 - IDLE AIR CONTROL (IAC)
These terminals connect the Idle Air Control valve, located on the throttle body, to the PCM. It is difficult to predict
what the voltage will be, and the measurement is unusable for any service procedures.
C11 - TRACTION CONTROL (TORQUE REQUESTED)
The ABS/ETC module will send a Nm signal to the PCM when torque reduction is requested from the ABS/ETC
module for traction control. This Nm signal should match closely with Torque Achieved Nm signal, when traction
control is being requested.
C12 - ELECTRONIC SPARK CONTROL (ESC) "KNOCK" INPUT SIGNAL
The Electronic Spark Control "knock" sensor detects when detonation is occurring in the combustion chambers.
When detected, the PCM will reduce the amount of spark advance being delivered on the EST output circuit to the
ignition module.
C13 - 3 - 2 DOWNSHIFT CONTROL SOLENOID
CONTROL
- AUTO TRANS ONLY -
The 3-2 control solenoid is a normally closed, pulse width modulated solenoid used to control the 3-2 downshift. The
PCM operates the 3-2 control solenoid at
a frequency of 50 Hz (cycles per second). The solenoid is constantly fed 12 volts and PCM controls the length of
time the path to earth for the electrical circuit is closed.
C14 - 3 - 2 SHIFT SOLENOID FEEDBACK
- AUTO TRANS ONLY -
The 3-2 Shift solenoid is a normally closed solenoid used to control the 3-2 downshift. The solenoid is constantly fed
12 volts and PCM controls the length of time the path to earth for the electrical circuit is closed. The PCM does this
to provide a smooth 3-2 downshift. If the PCM senses an incorrect voltage on this circuit when controlling the 3-2
downshift solenoid (i.e. - O volts with the solenoid OFF, or 12 volts with the solenoid ON) a DTC code 66 will set.
C15 - TORQUE CONVERTER CLUTCH - PULSE WIDTH MODULA TED APPLY SOLENOID FEEDBACK
- AUTO TRANS ONLY -
The PCM uses the pulse width modulated TCC apply solenoid to smoothly engage the torque converter clutch, after
the TCC "ON-OFF" solenoid is energised. By varying the duty cycle pulse width modulation, the PCM can slowly
engage the torque converter clutch, allowing very smooth TCC engagement. If the PCM senses an incorrect voltage
on this circuit when controlling the TCC PWM solenoid (i.e. - O volts with the solenoid OFF, or 12 volts with the
solenoid ON ) a DTC code 83 will set.
C16 - TORQUE CONVERTER CLUTCH - PULSE WIDTH MODULATED APPLY SOLENOID CONTROL
- AUTO TRANS ONLY -
The PCM uses the pulse width modulated TCC apply solenoid to smoothly engage the torque converter clutch, after
the TCC "ON-OFF" solenoid is energised. By varying the duty cycle pulse width modulation, the PCM can slowly
engage the torque converter clutch, allowing very smooth TCC engagement.
D1 - MASS AIR FLOW (MAF) INPUT SIGNAL
The PCM supplies a 5-volt signal voltage to the mass air flow sensor on this circuit. The mass air flow sensor
pulses the 5-volt signal to earth. These earth pulses occur at a very fast rate - from less than 500 per second (500
Hz) with no airflow through the sensor, to upwards of many thousands of pulses per second at high air flow rates
such as during acceleration. If measured, the voltage seen will be between 0.5 and 4.5 volts, depending on air flow
through the sensor.
D2 - NOT USED
D3 - CAMSHAFT POSITION INPUT SIGNAL
This signal is used by the PCM to "sequence" the energising of the fuel injectors, similar to the firing order of an
engine. This allows the PCM to operate the fuel injectors in a "sequential fuel injection" mode. The camshaft
position sensor is actually wired to the ignition module. The ignition module sends one pulse per every two
crankshaft revolutions to the PCM to determine actual camshaft position, and thus, engine cycle sequence.
D4 - CRANKSHAFT 18X INPUT SIGNAL
The 18X crankshaft reference input signal is used to very accurately control EST spark timing at low engine speeds
- below 1200 RPM. Below 1200 RPM, the PCM monitors the 18X signal to control spark timing. At engine speeds
above 1200 RPM, the PCM uses the 3X crankshaft reference input signal to control spark timing. (See 3X
crankshaft reference terminal D12)
D5 - VEHICLE SPEED SENSOR - OUTPUT SHAFT SPEED INPUT SIGNA L LOW
The transmission has an output shaft speed sensor used by the PCM to calculate vehicle speed, and to help
determine various automatic transmission shifting functions. It is a magnetic inductive sensor that generates an AC
voltage signal sent to the PCM. If measured with the digital AC voltmeter, no voltage will appear until the output
shaft begins turning.
D6 - NOT USED
D7 - NOT USED
D8 - NOT USED
D9 - IGNITION MODULE BYPASS CONTROL
- IGNITION SYSTEM MODE CONTROL -
With ignition "ON" and engine not running this terminal will have very low voltage. As soon as the PCM sees engine
RPM of more than 1600 RPM (Electronic Spark Timing "run" threshold) the PCM turns on 5 volts to the Ignition
Module Bypass Control circuit, causing the ignition module to allow the PCM to operate the ignition system.
D10 - ELECTRONIC SPA RK TIMING (EST) OUTPUT
This terminal will have very low voltage with the ignition "ON" but engine not running. With the engine running at
idle, the voltage should be slightly more than 1 volt. As the engine RPM goes up, this voltage will increases.
D11 - CRANKSHAFT REFERENCE INPUT SIGNAL LOW
This terminal should always be zero volts. It is connected through the ignition module to engine earth.
D12 - 3X CRANKSHAFT REFERENCE INPUT SIGNAL HIGH
This terminal could be called the "tach" input. It provides the PCM with RPM and crankshaft position information.
With ignition "ON" but engine not running, the voltage will be either high or low, depending on crankshaft position.
As the crankshaft turns, the voltage will be an average of the two readings. The PCM uses the 3X signal to control
fuel injection, and spark timing with engine speeds above 1200 RPM. (See 18X crankshaft reference terminal D4)
D13 - OXYGEN SENSOR INPUT SIGNAL
- RIGHT BANK -
With ignition "ON" and engine not running, the voltage should be 350 - 450 millivolts (0.350 - 0.450 volts). This is
the PCM-supplied 02 circuit "bias" voltage. With the engine running and after the 02 sensor is hot, the voltage
should be rapidly changing, somewhere between 10 - 1000 millivolts (0.010 - 1.000 volt).
D14 - OXYGEN SENSOR EARTH
- RIGHT BANK -
This terminal should have zero volts. It is connected directly to the engine earth. This terminal earths the PCM
circuitry for the O2 voltage monitor inside the PCM.
D15 - OXYGEN SENSOR INPUT SIGNAL
- LEFT BANK -
With ignition "ON" and engine not running, the voltage should be 350 - 450 millivolts (0.350 - 0.450 volts). This is
the PCM-supplied 02 circuit "bias" voltage. With the engine running and after the 02 sensor is hot, the voltage
should be rapidly changing, somewhere between 10 - 1000 millivolts (0.010 - 1.000 volt).
D16 - OXYGEN SENSOR EARTH
- LEFT BANK -
This terminal should have zero volts. It is connected directly to the engine earth. This terminal earths the PCM
circuitry for the O2 voltage monitor inside the PCM.
E - F TERMINAL CONNECTOR
E1 - LPG ENABLED
The PCM controls the operation of the LPG relay via this terminal. The PCM supplies an earth circuit to energise the
relay. If the PCM is not energising the LPG relay, the voltage measured at this terminal should equal battery voltage.
When the PCM energises the relay the voltage measured at this terminal will be pulled low, less than 0.2 volts.
E2 - FUEL INJECTOR 3 - CONTROL
E3 - FUEL INJECTOR 2 - CONTROL
E4 - FUEL INJECTOR 5 - CONTROL
The voltage seen at these terminals actually comes through the injectors, which are connected to +12 volts. With
the engine not running, the voltage seen would be battery voltage. With the engine running at idle, the charging
system increases the voltage slightly , so this voltage will increase. With higher engine RPM or more engine load,
the resulting increase in injector pulse frequency or injector pulse width will cause this voltage to appear slightly
less.
E5 - ENABLE LPG
The PCM uses this circuit to control the operation of the LPG smart unit. The PCM sends a pulse width modulated
signal to the smart unit when the ignition switch is first turned on, or when the engine is being cranked and while the
engine is running. If the engine stops running, the PCM will stop sending the signal to the smart unit.
E6 - PRNDL A
E7 - PRNDL B
E8 - PRNDL C
These circuits along with PCM circuit F15 indicate to the PCM what transmission gear the driver has selected. The
PCM will then send a command via the serial data line to the instrument panel cluster (smart cluster) to indicate to
the driver what gear has been selected.
E9 - EGR IGNITION
This is a ignition voltage input that runs between the EGR valve and the PCM. The PCM uses this input to
determine actual voltage supplied to the EGR valve.
E10 - EGR CONTROL
The PCM monitors EGR actual position and adjust pintle position accordingly. The PCM uses information from
several sensors to control the pintle position.
E11 - LPG WIRING CONFIGURATION
Battery voltage is applied to the PCM from the ignition switch circuit. Voltage on this terminal enables the PCM to
operate in two modes if the PCM is fitted with a specific LPG PROM. If the PCM does not see battery voltage at this
terminal it will only operate in the petrol mode.
E12 - OIL PRESSURE SWITCH
This is a earth input to the PCM from the Oil Pressure Switch indicating proper oil pressure when the engine is
running. If oil pressure is lost while the engine is running, the oil switch will open its contacts and the earth signal to
the PCM will be removed. When the PCM sees this loss of earth signal, the PCM will command the oil lamp ON.
E13 - NOT USED
E14 - TRANSMISSION PRESSURE CONTROL
SOLENOID (PCS) - LOW
- AUTO TRANS ONLY -
The 4L60-E automatic transmission uses an electrical solenoid to control hydraulic pressure inside the
transmission. This electrical solenoid allows the PCM to control "line pressure", similar to other automatic
transmissions that use a "throttle valve" cable or vacuum modulator. The duty cycle, and amount of current flow to
the PCS, are both controlled by the PCM. By monitoring this line, the PCM can determine if the commanded
amperage has gone to the PCS and returned to the PCM.
E15 - TRANSMISSION FLUID PRESSURE CONTROL SOLENOID (TFP) - HIGH
- AUTO TRANS ONLY -
The duty cycle, and amount of current flow to the TFP, are controlled by the PCM. This circuit is the B+ supply line
from the PCM to the TFP. The duty cycle and amperage are controlled by the PCM.
E16 - ENGINE COOLANT TEMPERA TURE AND THROTTLE POSITION SENSOR EARTH
This terminal should be zero volts. It is connected through the PCM circuitry to engine earth.
F1 - FUEL INJECTOR 4 - CONTROL
F2 - FUEL INJECTOR 1 - CONTROL
F3 - FUEL INJECTOR 6 - CONTROL
The voltage seen at these terminals actually comes through the injectors, which are connected to +12 volts. With
the engine not running, the voltage seen would be battery voltage. With the engine running at idle, the charging
system increases the voltage slightly , so this voltage will increase. With higher engine RPM or more engine load,
the resulting increase in injector pulse frequency or injector pulse width will cause this voltage to appear slightly
less.
F4 -AIR CONDITIONING RELAY CONTROL
When the A/C is requested, the BCM will communicate to the PCM via the serial data line, requesting A/C. The
PCM supplies the earth path on this terminal to energise the A/C control relay. The voltage will be less than 1 volt
when the PCM energises the relay. When the PCM does energise the A/C control relay, the voltage will be more
than 0.1, but less than 1 volt.
F5 - START RELAY CONTROL
When the PCM receives the proper Theft Deterrent signal, the PCM will supply a earth signal to Start Relay. This
will allow the vehicle to start. If a improper Theft Deterrent signal is sensed by the PCM, then the PCM will not
supply a earth signal to the Start Relay. This will prevent the starter motor from operating. In the LPG mode the
PCM will not energise the Start Relay if the throttle is open.
F6 - ENGINE COOLING FAN - HIGH SPEED RELAY CONTROL
This terminal will have battery voltage until the PCM energises the high speed cooling fan relay by supplying the
earth; then it will be close to zero. The input that causes the PCM to energise the high speed fan relay is the engine
coolant temperature sensor. The PCM will also energise the high speed fan relay in the Diagnostic Mode - i.e.,
ignition "ON," engine stopped, and DLC diagnostic "test" enable terminal earthed. Refer engine fan CHART A-12 in
this Section for further explanation.
(The Body Control Module operates the cooling fan low speed relay)
F7 - TRACTION CONTROL (ACTUA L TORQUE)
The PCM sends a pulse width modulated signal to the ABS/ETC control module informing the ABS/ETC module of
the actual engine torque in response to the requested torque signal sent to the PC from the ABS/ETC control
module. This signal should match closely with the Requested Torque Nm signal. A problem with the actual torque
circuit should cause a ABS/ETC DTC to set, and traction control to be disabled.
F8 - CRANKING SIGNAL INPUT
This cranking signal circuit provides an input for enabling fuel cutoff during a possible backfire situation. During an
engine start, when the key switch is released from the crank position before the engine is running, the engine may
backfire. The PCM stops all injector pulses when the engine speed is less than 450 RPM, coolant temperature is
greater than -4 degrees C, a cranking signal is not received, but was received within the previous 12.5 milliseconds
F9 - RANGE SIGNAL A INPUT SIGNAL
F10 - RANGE SIGNAL B INPUT SIGNAL
F11 - RANGE SIGNAL C INPUT SIGNAL
- AUTO TRANS ONLY -
Range signal "A", "B" and "C". The PCM sends out a buffered 12 volt signal to the pressure switch assembly,
located in the automatic transmission valve body. The 12 volt signal must pass through either a normally open or
normally closed switch to reach earth. When the switches) are closed, the signal should be near 0 volts. The PCM
monitors the status of these signals to determine which gear servo is actually receiving hydraulic apply pressure.
F12 - NORMA L / ECONOMY INPUT SIGNAL
- AUTO TRANS ONLY -
The PCM sends out a signal voltage of about 12 volts, and monitors the status of this circuit. In the ECONOMY
position the switch is open, the PCM voltage status signal remains high - about 12 volts, and the PCM does not
allow shift point changes. When the transmission switch is pressed to the POWER position the switch is closed and
the PCM voltage status signal is pulled low - about 0 volts. The PCM senses the zero voltage signal, and enables
power mode shifting only if other criteria are met. These criteria include throttle position and engine speed.
F13 - NOT USED
F14 - DIAGNOSTIC TEST ENABLE INPUT SIGNAL
This terminal is connected to the DLC diagnostic test enable terminal. When the diagnostic test terminal is not
earthed, this terminal will have 5 volts on it. When the DLC diagnostic test enable terminal is earthed, the resulting
zero voltage at the PCM will cause it to operate in Diagnostic Mode.
F15 - PRNDL
This circuit along with PCM circuits E6, E7, E8 indicate to the PCM what transmission gear the driver has selected.
The PCM will then send a command via the serial data line to the instrument panel cluster (smart cluster) to indicate
to the driver what gear has been selected.
F16 - INTAKE AIR TEMPERA TURE / TRANSMISSION FLUID TEMPERATURE / EGR VALVE / A/C PRESSURE
SENSOR EARTH CIRCUIT
This terminal should be zero volts. It is connected through the PCM circuitry to engine earth.
3.15 TECH 2 SCAN TOOL V6 LPG ENGINE DATA
The following TECH 2 scan Data listed in the table
may be used for comparison when diagnosing
faults on VT Series Models with an LPG systems:
1. After completing the
LPG VEHICLE PRELIMINARY DIAGNOSIS
and the ON-BOARD DIAGNOSTIC SYSTEM
CHECK.
2. Finding the on-board diagnostics are
functioning properly and
3. No diagnostic DTCs are displayed.
A TECH 2 SCAN TOOL THAT DISPLAYS
FAULTY DATA SHOULD NOT BE USED, AND
THE PROBLEM SHOULD BE REPORTED TO
THE M ANUFACTURER. THE USE OF A FAULTY
TECH 2 SCAN TOOL CAN RESULT IN
MISDIAGNOSIS AND UNNECESSARY PARTS
REPLACEMENT.
TEST DESCRIPTION:
Number(s) below refer to circled number(s) on the
diagnostic chart.
1. The scan position refers to the Tech 2 scan tool
"F0: DATA LIST" display pairs that will be
displayed in order, if the "YES" button is pressed.
After "Time From Start" parameter is displayed,
pressing the "YES" button will display pairs
starting on the top of the list again.
2. "Units Displayed" are the available ways of
displaying what each parameter is currently
operating in, or a value that is being sensed or
being outputted by the PCM.
3. "Typical Data Value" is separated into two parts.
These displayed values are typical of a normally
operating vehicle. The ignition "ON" comparison
should be performed first as this may lead to a
quick identification of a failure. The engine
running data should be compared to the ignition
"ON" data as a diagnostic check to m ak e s ure the
component or system is operating properly.
4 Ignition "ON" values are the typical values that
should be seen on the Tech 2 scan tool with the
ignition "ON," and engine stopped. Temperature
sensors should be compared to the actual
temperatures by letting the sensor sit overnight
and then comparing their values. A difference of
+35 degrees C from the actual temperature may
indicate a problem with the sensor. Use the
diagnostic aids chart for that sensor to compare
the resistance to temperature values.
Some "ON" or "OFF" switches may display an
abnormal state. If the chart states this position is
abnorm al, than this m ay be caused by an open or
short to earth, depending upon the normal state of
the switch. Refer to the proper Section or more
information on diagnosis.
5. "ENGINE RUNNING" typical data values are an
average of display values recorded from norm ally
operating vehicles, and are intended to represent
what a normally functioning s ystem would typically
display.
TECH 2 SCAN DATA ENGINE STREAM V6 LPG SELECTED
TYPICAL DATA VALUE (3)
SCAN POSITION
(1) UNITS DISPLAYED
(2) IGNITION " O N"
(4) ENGINE RUNNING
(5)
ENGINE SPEED RPM 0 RPM ± 100 RPM FROM DESIRE D RP M
(± 50 RPM IN DRIVE)
DESIRED ENGINE IDLE
SPEED RPM 0 RPM PCM IDLE COMMAND (VARIES
WITH TEMPERATURE)
ECT SENSOR VOLTS 1.90 V
(VARIES) 1.96 V
(VARIES)
COOLANT
TEMPERATURE DEGREES C +96 C
(VARIES) +96 C
(VARIES)
IAT SENSOR VOLTS 3. 82 V
(VARIES) 1.35 V
(VARIES)
INTAKE AIR
TEMPERATURE DEGREES C +22 C
(VARIES) +77 C
(VARIES)
MAF SENSOR Hz 0 Hz 2450 to 2600 Hz
MASS AIR FLOW GRAM /SEC 0 G/S 5 to 9 G/S
MASS AIR FLOW PER
CYLINDER mG/S 0.0 m G/S 140 to 180 m G/S
TPS SI GNA L VOLTS 0. 25V to 1.25V 0.25V to 1. 25V
THROTTLE ANGLE % 0 % 0 %
RIGHT O2 SENS OR
READY YES / NO NO YES
LEFT O2 SENSOR
READY YES / NO NO YES
RIGHT O2 SENS OR mV 447 mV 100 - 1000 mV AND VA RY ING
LEFT O2 SENSOR mV 447 mV 100 - 1000 mV AND V A RYING
RIGHT SHORT FUEL
TRIM % +0 % to -0 % +0 % to -0 %
LEFT SHORT FUEL TRIM % +0 % to -0 % +0 % to -0 %
RIGHT LONG TERM FUEL
TRIM % +0 % to -0 % +10 % to -10 %
LEFT LONG TERM FUEL
TRIM % +0 % to -0 % +10 % to -10 %
LTFT ENABLED YES / NO NO NO
FUELING MODE OPEN / CLOSED
LOOP OPEN LOOP OPEN LOOP
LTFT CELL CELL # 0 0
RIGHT O2 STATUS RICH / LEAN LEAN LEAN
LEFT O2 STATUS RICH / LEAN LEAN LEAN
RIGHT O2 CROSS
COUNTS COUNTS 0 0
LEFT O2 CROSS
COUNTS COUNTS 0 0
STFT DELTA % 0 % 0 %
LTFT DELTA % 0 % 0 %
DECELERATION FUE L
CUTOFF NO/YES NO NO
INJECTOR P ULS E WIDTH mS 27.5 mS 3.25 mS
INJECTOR V OLTA GE VOLTS 11. 4 V 14.0 V
AIR / FUE L RATIO % 0.0 : 1 14.7 : 1
PURGE PWM % 0 % 10 %
EGR POSITION
COMMANDED %0% 0%
EGR POSITION
FEEDBACK. %0% 0%
EGR PINTLE SENSOR VOLTS 0.6 VOLT 0.6 VOLT
BATTERY V OLTAGE VOLTS 11.3 V 14.0 V
REFERENCE V OLTS VOLTS 4.99 V 4.99 V
CRANK SWITCH ON/OFF OFF OFF
CAM SIGNAL MISSING
/PRESENT MISSING PRESENT
IDLE AI R CONTROL STEPS 169 STEPS 22 STEPS
LITRES PER HOUR L/HR 00.00 1 - 2 L/Hour
IDLE RPM VARIATION RPM 0 RPM 0 RPM
SPARK MODE BYPASS/EST BYPASS EST
SPARK ADVANCE DEGREES BTDC 14 ° BTDC + 14° BTDC
KNOCK SIGNAL KNOCK/NONE NONE NONE
KNOCK RETARD # OF DEGREES 0 °0 °
TCC SOLENOID ON / OFF OFF OFF
VEHICLE SPEED KM / H 0 KM/H 0 KM/H
A/C REQUEST ON /OFF OFF OFF
A/C CLUTCH ON / O F F OFF OFF
A/C PRESSURE S ENSOR VOLTS 1 - 2 V 1 - 2 V
A/C PRESSURE kPa 352 kPa 600 - 700 kPa A / C OFF
800 - 1000 kPa A /C ON
HIGH SPE ED FAN ON / OFF OFF OFF
LOW SPEED FAN
REQUEST ON / OFF OFF OFF
THEFT STATUS NO START/START START START
STARTER RELA Y OFF/ON ON ON
FUEL PUMP RELAY ON / OFF OFF ON
SUPERCHARGED
OPTION YES/NO NO NO
CRANK TIME SEC 0.0 SEC 0.5 SEC
DTC STA T US NO DTC(s)/
DTC(s) SET NO DTC(s) NO DTC(s)
TIME FROM START TIME 0:00:00 VARIES
‘PROM’ IDENTIFICATION FOUR DIGIT
NUMBER
(VARIES WITH
PROM UPDATE S )
1278 1278
CHECK P OWERTRA IN
LAMP OFF/0N ON OFF
REQUEST ED TORQUE Nm 0 Nm 0 Nm
ACTUAL TO RQUE Nm 0 Nm 0 Nm
LPG SWITCH OFF/ON OFF OFF
LPG FUEL ENABLE NO/YES YES YES
FUEL PETROL / LPG LPG LPG
LPG LOW PE TROL
CUTOFF YES/NO NO NO
LPG SMART SOLENOID ON/OFF ON ON