check engine light ISUZU AXIOM 2002 Service Workshop Manual

6E±220
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Aids
Check for the following conditions:

Poor connection at PCM ± Inspect harness connectors
for backed-out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal-to-wire connection.

Damaged harness ± Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
display on the Tech 2 while moving connectors and
wiring harnesses related to the sensor. A change in the
display will indicate the location of the fault.
Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the DTC to be set occurs. This
may assist in diagnosing the condition.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.2. The HO2S should be allowed to cool before
performing this test. If the HO2S heater is
functioning, the signal voltage will gradually increase
or decrease as the sensor element warms. If the
heater is not functioning, the HO2S signal will
remain near the 450 mV bias voltage.
4. This ensures that the ignition feed circuit to the
HO2S is not open or shorted. The test light should
be connected to a good chassis ground, in case the
HO2S low or HO2S heater ground circuit is faulty.
5. This checks the HO2S heater ground circuit.
6. This checks for an open or shorted HO2S heater
element.
11.An open HO2S signal or low circuit can cause the
HO2S heater to appear faulty. Check these circuits
before replacing the sensor.
DTC P0161 ± HO2S Heater Circuit Bank 2 Sensor 2

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2NOTE: If the engine has just been operating, allow the
engine to cool for at least 15 minutes before
proceeding.
1. Remove the fuel pump relay.
2. Connect a fused jumper at the fuel pump relay
socket, between the battery positive at the relay and
the relay wire that leads to the fuel pump and HO2S
fuses.
3. Ignition ªOFFº.
4. Install a Tech 2.
5. Ignition ªONº, engine ªOFFº.
6. Monitor the Bank 2 HO2S 2 voltage for several
minutes.
Did the HO2S voltage go from bias voltage to above or
below the specified values?
Above
650 mV or
Below
250 mV
Refer to
Diagnostic
Aids
Go to Step 3
3Inspect the fuse for the Bank 2 HO2S 2 ignition feed.
Is the fuse open?
ÐGo to Step 15Go to Step 4
41. Ignition ªOFFº.
2. Raise the vehicle.
3. Disconnect the Bank 2 HO2S 2 electrical connector.
4. Using a test light connected to a known good ground
(do not use Bank 2 HO2S 2 heater ground or Bank 2
HO2S 2 low), probe the ignition feed circuit at the
Bank 2 HO2S 2 electrical connector (PCM harness
side).
Does the test light illuminate?
ÐGo to Step 5Go to Step 7
5Connect the test light between the Bank 2 HO2S 2
ignition feed and the Bank 2 HO2S 2 heater ground.
Does the test light illuminate?
ÐGo to Step 6Go to Step 8

6E±228
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0172 ± Fuel Trim System Rich Bank 1

 
StepNo Ye s Value(s) Action
8Inspect the MAF sensor inlet screen for damage or for
the presence of foreign objects which may partially
block air flow through the screen and correct any
problem found.
Did your inspection of the MAF sensor reveal a
condition requiring repair or replacement?
ÐVerify repairGo to Step 9
9Start the engine and note the idle quality.
Is a low or unsteady idle being experienced?
ÐGo to Step 10Go to Step 11
101. Ignition ªOFFº.
2. Physically inspect the throttle body bore and throttle
plate for coking and foreign objects.
3. If a problem was found, repair as necessary.
Did your inspection reveal a condition requiring repair?
ÐVerify repairGo to Step 11
111. Disconnect the vacuum hose from the fuel pressure
regulator and inspect the hose for the presence of
fuel.
2. If fuel is present in the vacuum hose, replace the
fuel pressure regulator (refer to
Fuel Metering
System
).
Did the fuel pressure regulator require replacement?
ÐVerify repairGo to Step 12
12Ignition ªONº, engine ªOFFº, monitor the TP1 Angle
display on the Tech 2 while slowly depressing the
accelerator pedal.
Does the TP Angle display increase steadily and
evenly from minimum value at closed throttle to
maximum value at wide-open throttle?
Minimum 8%
Maximum
92%
Go to Step 13Go to Step 21
131. Disconnect the MAF sensor electrical connector.
2. Operate the vehicle in ªclosed loopº while
monitoring the ªBANK 1 L.T. FUEL TRIMº and
ªBANK 1 S. T. FUEL TRIMº display on the Tech 2.
Did both values change to near the specified value?
0%Go to Step 22Go to Step 14
141. Perform ªFuel System Pressure Testº.
2. If Fuel System Pressure Test isolates a problem,
repair as necessary (refer to
Engine Fuel or Fuel
Metering System
).
Did the Fuel System Pressure Test isolate a problem
requiring repair?
ÐVerify repairGo to Step 15
151. Ignition ªONº, engine ªOFFº.
2. Connect a test light between the harness connector
terminals of canister purge solenoid.
Is the test light on?
ÐGo to Step 16Go to Step 19
16Check for short to ground in the wire (YEL/RED)
between the canister purge solenoid and PCM terminal
S-48.
Was there a short to ground?
ÐGo to Step 17Go to Step 18
17Repair the short to ground.
Is the action complete?
ÐVerify repairÐ

6E±236
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0175 ± Fuel Trim System Rich Bank 2

 
StepNo Ye s Value(s) Action
7Visually and physically inspect the air intake duct for
collapse or restriction and repair if necessary.
Did your inspection reveal a problem requiring repair?
ÐVerify repairGo to Step 8
8Inspect the MAF sensor inlet screen for damage or for
the presence of foreign objects which may partially
block air flow through the screen and correct any
problem found.
Did your inspection of the MAF sensor reveal a
condition requiring repair or replacement?
ÐVerify repairGo to Step 9
9Start the engine and note the idle quality.
Is a low or unsteady idle being experienced?
ÐGo to Step 10Go to Step 11
101. Turn the ignition off and physically inspect the
throttle body bore, throttle plate, and IAC passages
for coking and foreign objects.
2. If a problem was found, repair as necessary.
Did your inspection reveal a condition requiring repair?
ÐVerify repairGo to Step 11
111. Disconnect the vacuum hose from the fuel pressure
regulator and inspect the hose for the presence of
fuel.
2. If fuel is present in the vacuum hose, replace the
fuel pressure regulator (refer to
Fuel Metering
System
).
Did the fuel pressure regulator require replacement?
ÐVerify repairGo to Step 12
121. Ignition ªONº, engine ªOFFº.
2. Monitor the TP Angle display on the Tech 2 while
slowly depressing the accelerator pedal.
Does the TP Angle display increase steadily and
evenly from minimum value at closed throttle to
maximum value at wide-open throttle?
Minimum 8%
Maximum
92%
Go to Step 13Go to Step 21
131. Disconnect the MAF sensor electrical connector.
2. Operate the vehicle in ªclosed loopº while
monitoring the ªBANK 2 L.T. FUEL TRIMº and
ªBANK 2 S.T. FUEL TRIMº display on the Tech 2.
Did both values change to near the specified value?
0%Go to Step 22Go to Step 14
141. Perform the ªFuel System Pressure Testº.
2. If Fuel System Pressure Test isolates a problem,
repair as necessary (refer to
Engine Fuel or Fuel
Metering System
).
Did the Fuel System Pressure Test isolate a condition
requiring repair?
ÐVerify repairGo to Step 15
151. Ignition ªONº, engine ªOFFº.
2. Connect a test light between the harness connector
terminals of canister purge solenoid.
Is the test light on?
ÐGo to Step 16Go to Step 19
16Check for short to ground in the wire (YEL/RED)
between the canister purge solenoid and PCM terminal
S-48.
Was there a short to ground?
ÐGo to Step 17Go to Step 18

6E±239
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Test Description
The number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. This step determines if DTC P0201 is the result of a
hard failure or an intermittent condition.
5. A special injector test connector is provided so that
the injectors can be electrically tested without
removal of the manifold. The test connector can be
identified by the blue connector lock which is
tethered to the wiring harness. If the light for
cylinder 1 is ªONº steady before cranking the engine
as well as while cranking the engine, then the
injector driver circuit is shorted to ground.
If the test light blinks while cranking, the PCM and
the wiring to the injectors are OK. The Fuel Injector
Coil Test Procedure will check if the injectors are
faulty.
R321054
7. Because the test light was ªONº steady, voltage to
the injector is OK, but the driver circuit is grounded
at all times. This step determines if the circuit is
shorted to ground or the PCM is faulty.
9. The reading should be about 12-14
.
10.Locating the open in the harness or in the injector
will require removal of the manifold to provide
access.
DTC P0201 ± Injector 1 Control Circuit

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Will the engine start?
ÐGo to Step 3
Go to Engine
Cranks But
Will Not Run
chart
31. Install the Tech 2. Clear the DTC.
2. Idle the engine for one minute.
Does DTC P0201 reset?
ÐGo to Step 5Go to Step 4
41. Review the Freeze Frame data with the ignition
ªONº and the engine ªOFFº and note the
parameters.
2. Operate the vehicle within the Freeze Frame
conditions as noted.
Does P0201 reset?
ÐGo to Step 5
Go to
Diagnostic
Aids
51. Engine ªOFFº.
2. Disconnect the injector connector.
3. Install an injector test light J-39021-65 on the
injector test connector.
4. Crank the engine and note the light.
Does the injector test light blink?
Ð
Go to Fuel
Injector Coil
Test
Procedure
Go to Step 6

6E±240
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0201 ± Injector 1 Control Circuit

 
StepNo Ye s Value(s) Action
6Note whether the injector test light for cylinder 1 was
ªOFFº or ªONº steady in step 5.
Was the test light ªONº steady while cranking the
engine?
ÐGo to Step 7Go to Step 9
71. Disconnect the PCM connector for the affected
injectors.
2. With a test light connected to B+, probe the affected
injector driver circuit.
Does the test light illuminate?
ÐGo to Step 8Go to Step 15
8Repair short to ground in the injector driver circuit.
Is the action complete?
Ð
Go to OBD
System
Check
Ð
91. Disconnect the injector test connector.
2. At the injector side of the harness, connect an
ohmmeter between the positive wire (red with blue
tracer) and the wire for cylinder 1 (green with white
tracer).
Does the ohmmeter indicate continuity?
ÐGo to Step 11Go to Step 10
10Repair the open injector harness wire or open injector.
Is the action complete?
ÐVerify repairÐ
11At the PCM side of the injector test connector, check
the green/white wire for a short to voltage.
Was there a short to voltage?
ÐGo to Step 12Go to Step 13
12Repair the short to voltage.
Is the action complete?
ÐVerify repairÐ
13Check for an open circuit between the injector test
connector and the PCM.
Was there an open circuit?
ÐGo to Step 14Go to Step 15
14Repair the open circuit.
Is the action complete?
ÐVerify repairÐ
15Replace 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 the 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±242
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Test Description
The number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. This step determines if DTC P0202 is the result of a
hard failure or an intermittent condition.
5. A special injector test connector is provided so that
the injectors can be electrically tested without
removal of the manifold. The test connector can be
identified by the blue connector lock which is
tethered to the wiring harness. If the light for
cylinder 2 is ªONº steady before cranking the engine
as well as while cranking the engine, then the
injector driver circuit is shorted to ground.
If the test light blinks while cranking, the PCM and
the wiring to the injectors are OK. The Fuel Injector
Coil Test Procedure will check if the injectors are
faulty.
R321055
7. Because the test light was ªONº steady, voltage to
the injector is OK, but the driver circuit is grounded
at all times. This step determines if the circuit is
shorted to ground or the PCM is faulty.
9.The reading should be about 12-14
.
10.Locating the open in the harness or in the injector
will require removal of the manifold to provide
access.
DTC P0202 ± Injector 2 Control Circuit

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Will the engine start?
ÐGo to Step 3
Go to Engine
Cranks But
Will Not Run
chart
31. Install the Tech 2. Clear the DTC.
2. Idle the engine for one minute.
Does DTC P0202 reset?
ÐGo to Step 5Go to Step 4
41. Review the Freeze Frame data with the ignition
ªONº and the engine ªOFFº and note the
parameters.
2. Operate the vehicle within the Freeze Frame
conditions as noted.
Does P0202 reset?
ÐGo to Step 5
Go to
Diagnostic
Aids
51. Engine ªOFFº.
2. Disconnect the injector test connector.
3. Install an injector test light J-39021-65 on injector
connector.
4. Crank the engine and note the light.
Does the cylinder 2 test light blink?
Ð
Go to Fuel
Injector Coil
Test
Procedure
Go to Step 6

6E±243
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0202 ± Injector 2 Control Circuit

 
StepNo Ye s Value(s) Action
6Note whether the injector test light for cylinder 2 was
ªOFFº or ªONº steady in step 5.
Was the test light ªONº steady while cranking the
engine?
ÐGo to Step 7Go to Step 9
71. Disconnect the PCM connector for the affected
injectors.
2. With a test light connected to B+, probe the affected
injector driver circuit.
Does the test light illuminate?
ÐGo to Step 8Go to Step 15
8Repair short to ground in the injector driver circuit.
Is the action complete?
Ð
Go to OBD
System
Check
Ð
91. Disconnect the injector test connector.
2. At the injector side of the harness, connect an
ohmmeter between the positive wire (red with blue
tracer) and the wire for cylinder 2 (green with orange
tracer).
Does the ohmmeter indicate continuity?
ÐGo to Step 11Go to Step 10
10Repair the open injector harness wire or open injector.
Is the action complete?
ÐVerify repairÐ
11At the PCM side of the injector test connector, check
the green/orange wire for a short to voltage.
Was there a short to voltage?
ÐGo to Step 12Go to Step 13
12Repair the short to voltage.
Is the action complete?
ÐVerify repairÐ
13Check for an open circuit between the injector test
connector and the PCM.
Was there an open circuit?
ÐGo to Step 14Go to Step 15
14Repair the open circuit.
Is the action complete?
ÐVerify repairÐ
15Replace 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 the 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±245
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Test Description
The number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. This step determines if DTC P0203 is the result of a
hard failure or an intermittent condition.
5. A special injector test connector is provided so that
the injectors can be electrically tested without
removal of the manifold. The test connector can be
identified by the blue connector lock which is
tethered to the wiring harness. If the light for
cylinder 3 is ªONº steady before cranking the engine
as well as while cranking the engine, then the
injector driver circuit is shorted to ground.
If the test light blinks while cranking, the PCM and
the wiring to the injectors are OK. The Fuel Injector
Coil Test Procedure will check if the injectors are
faulty.
R321056
7. Because the test light was ªONº steady, voltage to
the injector is OK, but the driver circuit is grounded
at all times. This step determines if the circuit is
shorted to ground or the PCM is faulty.
9. The reading should be about 12-14
.
10.Locating the open in the harness or in the injector
will require removal of the manifold to provide
access.
DTC P0203 ± Injector 3 Control Circuit

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Will the engine start?
ÐGo to Step 3
Go to Engine
Cranks But
Will Not Run
chart
31. Install the Tech 2. Clear the DTC.
2. Idle the engine for one minute.
Does DTC P0203 reset?
ÐGo to Step 5Go to Step 4
41. Review the Freeze Frame data with the ignition
ªONº and the engine ªOFFº and note the
parameters.
2. Operate the vehicle within the Freeze Frame
conditions as noted.
Does P0203 reset?
ÐGo to Step 5
Go to
Diagnostic
Aids
51. Engine ªOFFº.
2. Disconnect the injector test connector .
3. Install an injector test light J-39021-65 on injector
connector.
4. Crank the engine and note the light.
Does the cylinder 3 test light blink?
Ð
Go to Fuel
Injector Coil
Test
Procedure
Go to Step 6

6E±246
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0203 ± Injector 3 Control Circuit

 
StepNo Ye s Value(s) Action
6Note whether the injector test light for cylinder 3 was
ªOFFº or ªONº steady in step 5.
Was the test light ªONº steady while cranking the
engine?
ÐGo to Step 7Go to Step 9
71. Disconnect the PCM connector for the affected
injectors.
2. With a test light connected to B+, probe the affected
injector driver circuit.
Does the test light illuminate?
ÐGo to Step 8Go to Step 15
8Repair short to ground in the injector driver circuit.
Is the action complete?
Ð
Go to OBD
System
Check
Ð
91. Disconnect the injector test connector.
2. At the injector side of the harness, connect an
ohmmeter between the positive wire (red with blue
tracer) and the wire for cylinder 3 (green).
Does the ohmmeter indicate continuity?
ÐGo to Step 11Go to Step 10
10Repair the open injector harness wire or open injector.
Is the action complete?
ÐVerify repairÐ
11At the PCM side of the injector test connector, check
the green wire for a short to voltage.
Was there a short to voltage?
ÐGo to Step 12Go to Step 13
12Repair the short to voltage.
Is the action complete?
ÐVerify repairÐ
13Check for an open circuit between the injector test
connector and the PCM.
Was there an open circuit?
ÐGo to Step 14Go to Step 15
14Repair the open circuit.
Is the action complete?
ÐVerify repairÐ
15Replace 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 the 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±248
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Test Description
The number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. This step determines if DTC P0204 is the result of a
hard failure or an intermittent condition.
5. A special injector test connector is provided so that
the injectors can be electrically tested without
removal of the manifold. The test connector can be
identified by the blue connector lock which is
tethered to the wiring harness. If the light for
cylinder 4 is ªONº steady before cranking the engine
as well as while cranking the engine, then the
injector driver circuit is shorted to ground.
If the test light blinks while cranking, the PCM and
the wiring to the injectors are OK. The Fuel Injector
Coil Test Procedure will check if the injectors are
faulty.
R321057
7. Because the test light was ªONº steady, voltage to
the injector is OK, but the driver circuit is grounded
at all times. This step determines if the circuit is
shorted to ground or the PCM is faulty.
9. The reading should be about 12-14
.
10.Locating the open in the harness or in the injector
will require removal of the manifold to provide
access.
DTC P0204 ± Injector 4 Control Circuit

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Will the engine start?
ÐGo to Step 3
Go to Engine
Cranks But
Will Not Run
chart
31. Install the Tech 2. Clear the DTC.
2. Idle the engine for one minute.
Does DTC P0204 reset?
ÐGo to Step 5Go to Step 4
41. Review the Freeze Frame data with the ignition
ªONº and the engine ªOFFº and note the
parameters.
2. Operate the vehicle within the Freeze Frame
conditions as noted.
Does P0204 reset?
ÐGo to Step 5
Go to
Diagnostic
Aids
51. Engine ªOFFº.
2. Disconnect the injector test connector.
3. Install an injector test light J-39021-65 on injector
connector.
4. Crank the engine and note the light.
Does the cylinder 4 test light blink?
Ð
Go to Fuel
Injector Coil
Test
Procedure
Go to Step 6