check engine ISUZU AXIOM 2002 Service Repair Manual

6E±88
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Malfunction Indicator Lamp (MIL) ªONº Steady

StepActionValue(s)Ye sNo
1Was the ªOn-Board diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition ªOFFº, disconnect PCM.
2. Ignition ªONº, observe the MIL (Service Engine
Soon lamp).
Is the MIL ªONº?
ÐGo to Step 3Go to Step 5
31. Ignition ªOFFº, disconnect the instrument panel
cluster.
2. Check the MIL driver circuit between the PCM and
the instrument panel cluster for a short to ground.
3. If a problem is found, repair as necessary.
Was the MIL driver circuit shorted to ground?
Ð
Go to OBD
System
Check
Go to Step 4
4Replace the instrument panel cluster.
Is the action complete?
Ð
Go to OBD
System
Check
Ð
51. Ignition ªOFFº, reconnect the PCM.
2. Ignition ªONº, reprogram the EEPROM. Refer to
On-Vehicle Service in Powertrain Control Module
and Sensors
for procedures.
3. Using the Tech 2 output controls function, select
MIL dash lamp control and command the MIL
ªOFFº. (Refer to the Miscellaneous test)
Did the MIL turn ªOFFº?
Ð
Go to OBD
System
Check
Go to Step 6
6Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
On-Vehicle Service in
Powertrain Control Module and Sensors for
procedures.
And also refer to latest Service Bulletin.
Check to see if the Latest software is released or not.
And then Down Load the LATEST PROGRAMMED
SOFTWARE to the replacement PCM.
Is the action complete?
Ð
Go to OBD
System
Check
Ð

6E±89
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
No Reduced Power Lamp (RPL)
060R200073
Circuit Description
The Reduced Power lamp (RPL) should always be
illuminated and steady with the ignition ªONº and the
engine stopped. Ignition feed voltage is supplied to the
RPL bulb through the meter fuse. The powertrain control
module (PCM) orders the RPL ªONº signal for Multiplex
Control Unit. When Multiplex Control Unit is received RPL
ªONº signal that turn RPL ªONº by grounding the RPL
driver circuit.
Diagnostic Aids
An intermittent RPL may be caused by a poor connection,
rubbed-through wire insulation, or a wire broken inside
the insulation. Check for the following items:

Inspect the PCM and Multiplex Control Unit harness
and connections for improper mating, broken locks,
improperly formed or damaged terminals, poor
terminal to wire connection, and damaged harness.

If the engine runs OK, check for a faulty light bulb, an
open in the MIL driver circuit, or an open in the
instrument cluster ignition feed.

If the engine cranks but will not run, check for an open
PCM ignition or battery feed, or a poor PCM to engine
ground.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.2. A ªNo RPLº condition accompanied by a no±start
condition suggests a faulty PCM ignition feed or
battery feed circuit.
9. Using a test light connected to B+, probe each of the
Multiplex Control Unit ground terminals to ensure
that a good ground is present. Refer to Multiplex
Control Unit Terminal End View for terminal
locations of the Unit Terminal End View for terminal
locations of the Multiplex Control Unit ground
circuits.
12.Using a test light connected to B+, probe each of
the PCM ground terminals to ensure that a good
ground is present. Refer to PCM Terminal End View
for terminal locations of the PCM ground circuits.
21.In this step, temporarily substitute a known good
relay for the PCM relay. The horn relay is nearby,
and it can be verified as ªgoodº simply by honking
the horn. Replace the horn relay after completing
this step.
24.This vehicle is equipped with a PCM which utilizes
an electrically erasable programmable read only
memory (EEPROM). When the PCM is replaced,
the new PCM must be programmed. Refer to PCM
Replacement and Programming Procedures in
Powertrain Control Module (PCM) and Sensors.

6E±90
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
No Reduced Power Lamp (RPL)

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
Performed?
ÐGo to Step 2
Go to OBD
System
Check
2Attempt to start the engine.
Does the engine start?
ÐGo to Step 3Go to Step 11
3Check the following fuses:
MAIN(100A), B+1(60A), B+2(50A), METER(15A),
ECM(15A) , ENGINE(15A)
Was a problem found?
ÐGo to Step 14Go to Step 4
41. Ignition ºOFFº.
2. Disconnect the cluster meter connector.
3. Ignition ªONº, Probe the ignition feed circuit at the
cluster connector with a test light to ground.
Is the test light ªONº?
ÐGo to Step 5Go to Step 15
51. Ignition ªOFFº.
2. Disconnect the Multiplex Control Unit.
3. Check the circuit (Lamp driver Circuit) between
PCM and Multiplex Control Unit.
Was a problem found?
ÐGo to Step 16Go to Step 6
61. Reconnect the cluster meter connector.
2. Disconnect the Multiplex Control Unit.
3. Jumper the RPL driver circuit at the Multiplex
Control Unit connector to ground.
4. Ignition ªONº.
Is the RPL ªONº?
ÐGo to Step 7
Go to
Instrument
Panel in
Electrical
Diagnosis
71. Ignition ªOFFº.
2. Probe the ignition feed circuit at the Multiplex
Control Unit connector with a test light to ground.
3. Ignition ªONº.
Is the test light ªONº?
ÐGo to Step 8Go to Step 17
81. Ignition ªOFFº.
2. Disconnect the PCM.
3. Check the circuit (Lamp driver Circuit) between
PCM and Multiplex Control Unit.
Was a problem found?
ÐGo to Step 18Go to Step 9
9Check the Multiplex Control Unit ground connection
and circuit.
Was a problem found?
ÐGo to Step 19Go to Step 10
10Check for damaged terminals at the Multiplex Control
Unit.
Was a problem found?
ÐGo to Step 20Go to Step 11
111. Ignition ªONº.
2. Probe the ignition feed circuit at the PCM harness
connector with a test light to ground.
Is the test light ªONº?
ÐGo to Step 12Go to Step 21

6E±91
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
No Reduced Power Lamp (RPL)

 
StepNo Ye s Value(s) Action
121. Ignition ªOFFº.
2. Check for a faulty PCM ground connection and
Circuit.
Was a problem found?
ÐGo to Step 23Go to Step 13
13Check for damaged terminals at the PCM.
Was a problem found?
ÐGo to Step 24Go to Step 25
14Replace the fuse.
Is the action complete?
ÐVerify repairÐ
15Locate and repair the cluster meter battery feed open
circuit.
Is the action complete?
ÐVerify repairÐ
16Locate and repair the circuit between cluster meter and
Multiplex Control Unit open circuit.
Is the action complete?
ÐVerify repairÐ
17Locate and repair the circuit Multiplex Control Unit
battery feed open circuit.
Is the action complete?
ÐVerify repairÐ
18Locate and repair the between Multiplex Control Unit
and PCM open circuit.
Is the action complete?
ÐVerify repairÐ
19Locate and repair the ground connection for Multiplex
Control Unit circuit.
Is the action complete?
ÐVerify repairÐ
20Reconnect the Multiplex Control Unit. circuit.
Is the action complete?
ÐVerify repairÐ
21Substitute a known ªgoodº relay for the PCM main
relay.
Was the malfunction fixed?
ÐVerify repairGo to Step 22
22Repair the open in the ignition feed circuit.
Is the action complete?
ÐVerify repairÐ
23Locate and repair the ground connection for PCM
circuit.
Is the action complete?
ÐVerify repairÐ
24Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed.
Refer to ON-Vehicle Service in Power Control Module
and Sensors for procedures.
And also refer to latest Service Bulletin.
Check to see if the latest software is released or not.
And then Down Load the LATEST PROGRAMMED
SOFTWARE to the replacement PCM.
Is the action complete?
ÐVerify repairÐ

6E±92
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
No Reduced Power Lamp (RPL)

 
StepNo Ye s Value(s) Action
251. Ignition ªOFFº.
2. Reconnect all connectors.
3. Install the Tech 2.
4. Ignition ªONº.
5. Using the Tech 2 output controls function, select
RPL dash lamp control and command the RPL
ªONº. (Refer to the Miscellaneous test)
Did the RPL turn ªONº?
ÐVerify repairGo to Step 26
261. Ignition ªOFFº.
2. Disconnect the PCM.
3. Check the circuit (DLC line) between PCM and
DLC.
Was a problem found?
ÐGo to Step 27Go to Step 24
27Locate and repair the circuit the between PCM and
DLC.
Is the action complete?
ÐGo to Step 25Ð

6E±93
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Reduced Power Lamp (RPL) ªONº Steady
060R200073
Circuit Description
The Reduced Power lamp (RPL) should always be
illuminated and steady with the ignition ªONº and the
engine stopped. Ignition feed voltage is supplied to the
RPL bulb through the meter fuse. The powertrain control
module (PCM) orders the RPL ªONº signal for Multiplex
Control Unit. When Multiplex Control Unit is received RPL
ªONº signal that turn RPL ªONº by grounding the RPL
driver circuit.
The RPL should not remain ªONº with the engine running
and no DTC(s) set. A steady RPL with the engine running
and no DTC(s) suggests a short to ground in the RPL
driver circuit.
Diagnostic Aids
An intermittent RPL may be caused by a poor connection,
rubbed through wire insulation, or a wire broken inside the
insulation. Check for the following items:
Poor connection or damaged harness ± Inspect the
PCM harness and connectors for improper mating,
broken locks, improperly formed or damaged
terminals, poor terminal to wire connection, and
damaged harness.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. If the RPL does not remain ªONº when the Multiplex
Control Unit is disconnected, the RPL driver wiring
is not faulty.
3. If the RPL driver circuit is OK, the instrument panel
cluster is faulty.
10. This vehicle is equipped with a PCM which utilizes
an electrically erasable programmable read only
memory (EEPROM). When the PCM is replaced,
the new PCM must be programmed. Refer to PCM
Replacement and Programming Procedures in
Powertrain Control Module (PCM) and Sensors.

6E±94
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Reduced Power Lamp (RPL) ªONº Steady

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition ªOFFº, disconnect Multiplex Control Unit.
2. Ignition ªONº, observe the RPL (Reduced Power
Lamp).
Is the RPL ªONº?
ÐGo to Step 3Go to Step 4
31. Ignition ªOFFº, disconnect the instrument panel
cluster.
2. Check the RPL driver circuit between the Multiplex
Control Unit and the instrument panel cluster for a
short to ground.
3. If a problem is found, repair as necessary.
Was the RPL driver circuit shorted to ground?
ÐVerify repairGo to Step 4
41. Replace the Multiplex Control Unit.
2. Install the Tech 2
3. Ignition ªONº.
4. Using the Tech 2 output controls function, select
RPL dash lamp control and command the RPL
ªOFFº. (Refer to the Miscellaneous test)
Did the MIL turn ªOFFº?
ÐVerify repairGo to Step 5
51. Ignition ªOFFº.
2. Disconnect the PCM.
3. Check the circuit (Lamp driver Circuit) between
PCM and Multiplex Control Unit.
Was a problem found?
ÐGo to Step 6Go to Step 7
6Locate and repair the circuit between Multiplex Control
Unit and PCM open circuit.
Is the action complete?
ÐGo to Step 7Ð
71. Install the Tech 2
2. Ignition ªONº.
3. Using the Tech 2 output controls function, select
RPL dash lamp control and command the RPL
ªOFFº. (Refer to the Miscellaneous test)
Did the MIL turn ªOFFº?
Ð
Go to Verify
repair
Go to Step 8
81. Ignition ºOFFº.
2. Disconnect the PCM.
3. Check the circuit (DLC line) between PCM and
DLC.
Was a problem found?
ÐGo to Step 9Go to Step 10

6E±95
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Reduced Power Lamp (RPL) ªONº Steady

 
StepNo Ye s Value(s) Action
9Locate and repair the circuit between PCM and DLC.
Is the action complete?
ÐGo to Step 2Ð
10Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed.
Refer to ON-Vehicle Service in Power Control
Module and Sensors for procedures.
And also refer to latest Service Bulletin.
Check to see if the latest software is released or not.
And then Down Load the LATEST PROGRAMMED
SOFTWARE to the replacement PCM.
Is the action complete?
Ð
Go to OBD
System
Check
Ð

6E±96
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Starter Control System Check
060R200062
Circuit Description
Starter control system is controlled by the Power Train
Control Module (PCM). The PCM monitors starter switch
signal (ªSTARTºposition ) and MODE switch (park or
neutral) signal. PCM is operated by the ignition switch.
Ignition feed voltage is supplied to the MODE switch and
starter relay through the engine fuse. PCM turns the
starter relay ªONº by grounding the starter relay driver
circuit.
The starter motor is operated until 30 seconds based on
starter relay signal.
Diagnostic Aids
An intermittent may be caused by the following:

Poor connections.

Mis routed harness.
Rubbed through wire insulation.

Broken wire inside the insulation.
Test Description
2.If Anti-theft system is ªONº, PCM does not operate
starter control system.
19.Refer to
6D section.
21.Refer to 6D section.
24.This vehicle is equipped with a PCM which utilizes
an electrically erasable programmable read only
memory (EEPROM). When the PCM is replaced,the
new PCM must be programmed.
Refer to
PCM Replacement and Programming
Procedures in Powertrain Control Module (PCM) and
Sensors.
Starter Control System Check

StepActionValue(s)Ye sNo
1Was the ªOn-Board (OBD) System Checkº performed?
ÐGo to Step 2
Go to OBD
System
Check
2Was the ªAnti-theft Systemº normally? Refer to
Owner's Manual.ÐGo to Step 3Go to Step 7

6E±97
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Starter Control System Check

 
StepNo Ye s Value(s) Action
31. Gear position is ªpark or neutralº.
2. Do not depress the accelerator pedal.
3. Turn the key to ªSTARTº position.
4. Release the key switch to the to ªONº position.
Does the engine crank?
ÐGo to Step 27Go to Step 4
41. Install the Tech 2.
2. Select ªDisplay DTCsº with the Tech 2.
Are any DTCs stored?
ÐGo to Step 5Go to Step 6
5Review and record for Tech 2 Failure Records data and
DTCs.
Were any DTCs information stored?
Ð
Go to DTCs
Chart
Ð
61. Gear position is ªpark or neutralº.
2. Do not depress the accelerator pedal.
3. Turn the key to ªSTARTº position.
Is the engine cranking?
ÐGo to Step 27Go to Step 7
7Check the anti±theft module circuit. Check the circuit
between PCM and anti±theft module.
Is the problem found?
ÐGo to Step 8Go to Step 9
8Repair the circuit as necessary.
Is the action complete?
ÐVerify repairÐ
91. Probe the anti-theft module circuit to GND.
2. Turn the key to ªSTARTº position.
Is the engine cranking?
ÐGo to Step 10Go to Step 11
10Check the anti-theft system. Refer to section 8H
anti-theft.
ÐVerify repairÐ
11Check the starter relay, starter fuse and engine fuse.
Is the problem found?
Go to Step 12Go to Step 13
12Replace the starter relay, starter fuse and engine fuse.
Is the action complete?
ÐVerify repairÐ
13Check the starter circuit.
1. Ignition is ºOFFº.
2. Remove the starter relay.
3. Check the circuit between starter relay and starter
motor.
Is the problem found?
ÐGo to Step 14Go to Step 15
14Repair the circuit as necessary.
Is the action complete?
ÐVerify repairÐ
15Check the starter circuit.
1. Remove the main fuse (100A).
2. Check the circuit between main fuse and starter
motor.
3. Check the circuit between GND and starter motor.
Is the problem found?
ÐGo to Step 16Go to Step 17