2002 ISUZU AXIOM check engine

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6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0325
ION Sensing Module/ION Sensing Knock Intensity Circuit Fault
060R200055
Circuit Description
The Power Control Module (PCM) checks the validity of
the signals used in the ION Sensing module at the
following engine operating conditions.

The test is performed to evacuate the Knock Intensity
(KI) signal pulse width if it is within a predetermined
range. If the KI signal pulse width is out of the
predetermined range, the fail counter will be
incremented. If the failure counter exceeds the
calibration, then test is complete and a failure will be
reported. If the sample counter threshold is reached
before the failure threshold, then the test is complete
and a pass will be reported. This test will detect an
open/short in the KI line circuit, ION module faults and
analog input faults in the PCM.
Conditions for setting the DTC

Ignition voltage is between 10volt and 16 volts.

No Crank DTCs set.

No EST DTCs set.

No Misfire DTCs set.
Action Taken When the DTC Sets

The PCM will ON the MIL after second trip with
detected the fault.

The PCM calculates an air flow value based on idle air
control valve position, throttle position, RPM and
barometric pressure.
The PCM will store condition which were present when
the DTC was set as Freeze Frame and in the Failure
Records data.
Conditions for Clearing the MIL/DTC

The PCM will turn the MIL ªOFFº on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.

A history DTC P0325 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.

DTC P0325 can be cleared using the Tech2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids
An intermittent may be caused by the following:

Poor connections.

Misrouted harness.

Rubbed through wire insulation.

Broken wire inside the insulation.
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.

6E±273
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
If the harness appears to be OK, observe the Knock
Present, Knock Sensor Noise Channel 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.If DTC P0325 cannot be duplicated, the information
included in the Failure Records data can be useful in
determined vehicle mileage since the DTC was last
set.
If it is determined that the DTC occurs intermittently,
performing the DTC P0325 Diagnostic Chart may
isolate the cause of the fault.
DTC P0325 - ION Sensing Module Knock Intensity Circuit Fault

StepActionValue(s)Ye sNo
1Was the ªOn-Board (OBD) System Checkº performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition ªONº, engine ªOFFº.
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records
conditions as noted.
4. Using a Tech 2, monitor ªDTCº info for DTC P0325.
Does the Tech 2 indicate DTC P0325 failed this
ignition?
ÐGo to Step 3
Refer to
Diagnostic
Aids
31. Ignition ªOFFº.
2. Disconnect the ION sensing module.
3. Disconnect the PCM.
Is the action complete?
ÐGo to Step 4Ð
4Check the ION sensing harness between the PCM
(F68) and ION sensing module circuit (RED Wire) at
the KI line harness connector.
Was a problem found?
ÐVerify repairGo to Step 5
51. Disconnect the ignition coil.
Is the action complete?
ÐGo to Step 6Ð
6Check the ION sensing harness for open or short circuit
between the ignition coil and ION sensing module
circuit at the harness connector.
Was a problem found?
ÐVerify repairGo to Step 7
7Check the following items;
1. Ignition coil and ignition coil circuit.
2. Ignition coil ground circuit for a poor connection.
3. If a problem is found, repair wiring harness as
necessary.
Was a problem found?
ÐVerify repairGo to Step 8
8Replace the Ignition coil.
Is the action complete?
ÐVerify repairGo to Step 9
9Check the following items;
1. ION sensing module ground circuit for a poor
connection.
2. If a problem is found, repair wiring harness as
necessary.
Was a problem found?
ÐGo to Step 10Go to Step 11
10Repair wiring harness.
Is the action complete?
ÐVerify repairGo to Step 11

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6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0325 - ION Sensing Module Knock Intensity Circuit Fault

 
StepNo Ye s Value(s) Action
11Replace the ION Sensing module.
Is the action complete?
ÐVerify repairGo to Step 12
12Replace 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

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6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Aids
An intermittent may be caused by a poor connection,
rubbed-through wire insulation or a wire broken inside the
insulation. Check for:

Poor connection - Inspect the PCM harness and
connectors for 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, disconnect
the PCM, turn the ignition on and observe a voltmeter
connected to the 58X reference circuit at the PCM
harness connector while moving connectors and
wiring harnesses related to the PCM. A change in
voltage 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.

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6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0336 ± 58X Reference Signal Circuit

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 3
Go to ªEngine
Cranks But
Will Not Runº
chart
31. Review and record Failure Records information.
2. Clear DTC P0336.
3. Start the engine and idle for 1 minute.
4. Observe DTCs.
Is DTC P0336 set?
ÐGo to Step 4
Refer to
Diagnostic
Aids
41. Disconnect the PCM and CKP sensor.
2. Check for an open or a short to ground in the 58X
reference circuit between the CKP sensor
connector and the PCM harness connector.
3. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 5
51. Reconnect the PCM and CKP sensor.
2. Connect a DVM to measure voltage on the 58X
reference circuit at the PCM connector.
3. Observe the voltage while cranking the engine.
Is the voltage near the specified value?
2.5 VGo to Step 8Go to Step 6
6Check the connections at the CKP sensor and replace
the terminals if necessary.
Did any terminals require replacement?
ÐVerify repairGo to Step 7
7Replace the CKP sensor. Use caution to avoid any hot
oil that may drip out.
Is the action complete?
ÐVerify repairÐ
8Check connections at the PCM and replace the
terminals if necessary.
Did any terminals require replacement?
ÐVerify repairGo to Step 9
9Replace 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?
ÐVerify repairÐ

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6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Aids
An intermittent may be caused by a poor connection,
rubbed-through wire insulation or a wire broken inside the
insulation. Check for:

Poor connection ± Inspect the PCM harness and
connectors for 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, disconnectthe PCM, turn the ignition on and observe a voltmeter
connected to the 58X reference circuit at the PCM
harness connector while moving connectors and
wiring harnesses related to the PCM. A change in
voltage 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.
DTC P0337 ± CKP Sensor Circuit Low Frequency

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 Chart 3
31. Review and record Failure Records information.
2. Clear DTC P0337.
3. Start the engine and idle for 1 minute.
4. Observe DTCs.
Is DTC P0337 set?
ÐGo to Step 4
Refer to
Diagnostic
Aid
41. Disconnect the CKP sensor.
2. Ignition ªONº.
3. Using a DVM, verify that 5 V reference and ground
are being supplied at the sensor connector (PCM
side).
Are 4-6 volts and ground available at the sensor?
ÐGo to Step 7Go to Step 5
51. Ignition ªONº.
2. With a DVM, backprobe the PCM connector 5 V
reference and ground connections.
Are 5 V reference and ground available at the PCM?
ÐGo to Step 6Go to Step 11
6Check 5 V reference or ground between the CKP
sensor and PCM and repair the open circuit, short to
ground or short to voltage.
Is the action complete?
ÐVerify repairÐ
71. Ignition ªOFFº.
2. Disconnect the PCM and CKP sensor.
3. Check for an open or a short to ground in the 58X
reference circuit between the CKP sensor
connector and the PCM harness connector.
4. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 8
81. Reconnect the PCM and CKP sensor.
2. Connect a DVM to measure voltage on the 58X
reference circuit at the PCM connector.
3. Observe the voltage while cranking the engine.
Is the voltage near the specified value?
2.5 VGo to Step 11Go to Step 9
9Check the connections at the CKP sensor and replace
the terminals if necessary.
Did any terminals require replacement?
ÐVerify repairGo to Step 10

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6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0337 ± CKP Sensor Circuit Low Frequency

 
StepNo Ye s Value(s) Action
10Replace the CKP sensor. Use caution and avoid hot oil
that may drip out.
Is the action complete?
ÐVerify repairÐ
11Check the connections at the PCM and replace the
terminals if necessary.
Did any terminals require replacement?
ÐVerify repair Go to Step 12
12Replace 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?
ÐVerify repairÐ

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

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

Damaged harness ± Inspect the wiring harness for
damage. If the harness appears to be OK, observe theTech 2 display related to DTC P0351 while moving the
connector and wiring related to the ignition system. 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.
DTC P0351 ± Ignition 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
21. Ignition ªONº, engine ªOFFº.
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Record
conditions as noted.
4. Use a Tech 2 to monitor the ªDTCº information for
DTC P0351 until the DTC P0351 test runs.
5. Note the test result.
Does the Tech 2 indicate DTC P0351 failed this ignition
cycle?
ÐGo to Step 3
Go to
Diagnostic
Aids
3Check for faulty connection at ignition coil.
Was a problem found?
ÐVerify repairGo to Step 4
4Check for faulty connection at PCM connector.
Was a problem found?
ÐVerify repair Go to Step 5
51. Ignition ªONº, engine ªOFFº.
2. Back probe the ignition control circuit 1 at the ION
Sensing Module with a DVM.
Is the voltage near the specified value?
25-55 mVGo to Step 6Go to Step 9
61. Ignition ªONº, engine running.
2. Back probe the ignition control circuit at the ION
Sensing Module for the cylinder being tested.
Is the voltage in the specified range, rapidly toggling
back and forth to a reading 20-50 mV higher?
100-180 mVGo to Step 7Go to Step 13
71. Ignition ªOFFº.
2. Disconnect the 3-pin and connector at the ignition
coil.
3. Check ignition control circuit 1 voltage at the ignition
coil connector while cranking the engine.
Does the voltage measure between the specified
values?
200-1200 mVGo to Step 8Go to Step 11
8Replace the ignition coil.
Is the action complete?
ÐVerify repairÐ
91. Ignition ªOFFº.
2. Disconnect the PCM and the ignition coil.
3. Check ignition control circuit 1 for short to ground.
Was a problem found?
ÐVerify repairGo to Step 10
10Check ignition control circuit 1 for short to voltage.
Was a problem found?
ÐVerify repairGo to Step 13