ISUZU AXIOM 2002 Service Repair Manual

6E±434
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1271 ± APS 1± 2 Correlation Error

StepActionValue(s)Ye sNo
1Was the ªOn-Board (OBD) System Checkº performed?
ÐGo to Step 2
Go to OBD
System
Check
2Was the ªElectric Throttle Control (ETC) System
Checkº performed?
ÐGo to Step 3
Go to ETC
System
Check
3Observe the AP angle reading on the Tech 2 while
slowly opening the throttle.
Does the AP angle increase steadily and evenly from
the closed throttle value to the wide open throttle
value?Idle position
AP sensor 1
=13 % AP
sensor 2 =85
~ 89 % Wide
open throttle
AP sensor 1
=85 ~ 89 %
AP sensor 2
=11 ~ 15 %
Refer to
Diagnostic
Aids
Go to Step 4
41. Disconnect the AP sensor.
2. Observe the AP sensor reading on the Tech 2.
Is the AP sensor reading near the specified value?
0VGo to Step 5Go to Step 6
51. Connect a test light between the 5 V supply circuit
and the AP sensor signal circuit at the AP1, AP2
sensor harness connector.
2. Observe the AP sensor reading on the Tech 2.
Is the AP sensor reading near the specified value?
5VGo to Step 8Go to Step 7
6Check the following items;
1. AP1and AP2 signal circuit for a short to voltage.
2. AP1and AP2 sensor ground circuit for high
resistance between the PCM and the AP sensor.
3. AP1and AP2 sensor ground circuit for a poor
connection.
4. If a problem is found, repair wiring harness as
necessary.
Was a problem found?
ÐVerify repairGo to Step 9
7Check the following items;
1. AP1and AP2 signal circuit or 5 V supply circuit for a
poor connection.
2. AP1and AP2 signal circuit or 5 V supply circuit for
high resistance between the PCM and the AP1 and
AP2 sensor.
3. If a problem is found, repair wiring harness as
necessary.
Was a problem found?
ÐVerify repairGo to Step 8

6E±435
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1271 ± APS 1± 2 Correlation Error

 
StepNo Ye s Value(s) Action
8Replace the AP sensor.
Is the action complete?
ÐVerify repairÐ
9Replace 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±436
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1272 APS 2 ± 3 Correlation Error
060R200064
Circuit Description

The accelerator position (AP) sensor circuit provides a
voltage signal relative to accelerator pedal angle.
The accelerator pedal sensor (AP2) will vary from
about 87 % at idle position to about 13 % at wide
open throttle (WOT) to specified voltage (about 5V).
This code detects a correlation error betweenAPS2
and APS3.
Conditions for setting the DTC

The Ignition is ªONº.

The acceleration pedal angle difference is more than
4.5 % between ASP2 and APS3 for more than 265
millisecond.
Action Taken When the DTC Sets

The PCM will not turn the malfunction indicator lamp
(MIL) ªONº.

The PCM will store conditions which were present
when the DTC was set as Failure Records only. This
information will not be stored as Freeze Frame 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 P1272 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.
DTC P1272 can be cleared using the Tech 2 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. If the harness appears to be OK, observe the
AP sensor 2, AP sensor 3 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 P1272 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
P1272 Diagnostic Chart may isolate the cause of the
fault.

6E±437
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1272 ± APS 2 ± 3 Correlation Error

StepActionValue(s)Ye sNo
1Was the ªOn-Board (OBD) System Checkº performed?
ÐGo to Step 2
Go to OBD
System
Check
2Was the ªElectric Throttle Control (ETC) System
Checkº performed?
ÐGo to Step 3
Go to ETC
System
Check
3Observe the AP angle reading on the Tech 2 while
slowly opening the throttle.
Does the AP angle increase steadily and evenly from
the closed throttle value to the wide open throttle
value?Idleposition
AP sensor 2
=86 ~ 88 %
AP sensor 3
=86 ~ 88 %
Wide open
throttle AP
sensor 2 =12
~ 14 % AP
sensor 3 =32
~ 36 %
Refer to
Diagnostic
Aids
Go to Step 4
41. Disconnect the AP sensor.
2. Observe the AP sensor reading on the Tech 2.
Is the AP sensor reading near the specified value?
0VGo to Step 5Go to Step 6
51. Connect a test light between the 5 Voltage supply
circuit and the AP sensor signal circuit at the AP2
and AP3 sensor harness connector.
2. Observe the AP sensor reading on the Tech 2.
Is the AP sensor reading near the specified value?
5VGo to Step 8Go to Step 7
6Check the following items;
1. AP2 and AP3 signal circuit for a short to voltage.
2. AP2 and AP3 sensor ground circuit for high
resistance between the PCM and the AP sensor.
3. AP2 and AP3 sensor ground circuit for a poor
connection.
4. If a problem is found, repair wiring harness as
necessary.
Was a problem found?
ÐVerify repairGo to Step 9
7Check the following items;
1. AP2 and AP3 signal circuit or 5 voltage supply
circuit for a poor connection.
2. AP2 and AP3 signal circuit or 5 voltage supply
circuit for high resistance between the PCM and the
AP2 and AP3 sensor.
3. If a problem is found, repair wiring harness as
necessary.
Was a problem found?
ÐVerify repairGo to Step 8

6E±438
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1272 ± APS 2 ± 3 Correlation Error

 
StepNo Ye s Value(s) Action
8Replace the AP sensor.
Is the action complete?
ÐVerify repairÐ
9Replace 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±439
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1273 APS 1 ± 3 Correlation Error
060R200064
Circuit Description

The accelerator position (AP) sensor circuit provides a
voltage signal relative to accelerator pedal angle.
The accelerator pedal sensor (AP1) will vary from
about 13 % at idle position to about 87 % at wide
open throttle (WOT) to specified voltage (about 5V).
This code detects a correlation error between APS1
and APS3.
Conditions for setting the DTC

The Ignition is ªONº.

The accelerator pedal angle difference is more than 4.5
% between ASP1 and APS3 for more than 265
milliseconds.
Action Taken When the DTC Sets

The PCM will not turn the malfunction indicator lamp
(MIL) ªONº.

The PCM will store conditions which were present
when the DTC was set as Failure Records only. This
information will not be stored as Freeze Frame 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 P1273 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.
DTC P1273 can be cleared using the Tech 2 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. If the harness appears to be OK, observe the
AP sensor 1, AP sensor 3 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 P1273 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
P1273 Diagnostic Chart may isolate the cause of the
fault.

6E±440
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1273 ± APS 1 ± 3 Correlation Error

StepActionValue(s)Ye sNo
1Was the ªOn-Board (OBD) System Checkº performed?
ÐGo to Step 2
Go to OBD
System
Check
2Was the ªElectric Throttle Control (ETC) System
Checkº performed?
ÐGo to Step 3
Go to ETC
System
Check
3Observe the AP angle reading on the Tech2 while
slowly opening the throttle.
Does the AP angle increase steadily and evenly from
the closed throttle value to the wide open throttle
value?Idleposition
AP sensor 1
=13 % AP
sensor 3 =85
~ 89 % Wide
open throttle
AP sensor 1
=85 ~ 89 %
AP sensor 3
=32 ~ 36 %
Refer to
Diagnostic
Aids
Go to Step 4
41. Disconnect the AP sensor.
2. Observe the AP sensor reading on the Tech 2.
Is the AP sensor reading near the specified value?
0VGo to Step 5Go to Step 6
51. Connect a test light between the 5 Voltage supply
circuit and the AP sensor signal circuit at the AP1
and AP3 sensor harness connector.
2. Observe the AP sensor reading on the Tech 2.
Is the AP sensor reading near the specified value?
5VGo to Step 8Go to Step 7
6Check the following items;
1. AP1 and AP3 signal circuit for a short to voltage.
2. AP1 and AP3 sensor ground circuit for high
resistance between the PCM and the AP sensor.
3. AP1 and AP3 sensor ground circuit for a poor
connection.
4. If a problem is found, repair wiring harness as
necessary.
Was a problem found?
ÐVerify repairGo to Step 9
7Check the following items;
1. AP1 and AP3 signal circuit or 5 voltage supply
circuit for a poor connection.
2. AP1 and AP3 signal circuit or 5 voltage supply
circuit for high resistance between the PCM and the
AP1 and AP3 sensor.
3. If a problem is found, repair wiring harness as
necessary.
Was a problem found?
ÐVerify repairGo to Step 8

6E±441
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1273 ± APS 1 ± 3 Correlation Error

 
StepNo Ye s Value(s) Action
8Replace the AP sensor.
Is the action complete?
ÐVerify repairÐ
9Replace 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±442
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1275 APS 1 Output Fault
060R200064
Circuit Description

The accelerator position (AP) sensor circuit provides a
voltage signal relative to accelerator pedal angle.
The accelerator pedal sensor (AP1) will vary from
about 13 % at idle position to about 87 % at wide
open throttle (WOT) to specified voltage (about 5V).
This code detects a continuous short to ground or
high in either the circuit or the sensor.
Conditions for setting the DTC

The Ignition is ªONº.

The accelerator pedal sensor 1 is less than 2.5 % or
more than 97 % in the specified voltage (5V) for more
than 62.4 milliseconds.
Action Taken When the DTC Sets

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

The PCM will store conditions 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 P1275 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.
DTC P1275 can be cleared using the Tech 2 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. If the harness appears to be OK, observe the
APP sensor 1 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 P1275 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
P1275 Diagnostic Chart may isolate the cause of the
fault.

6E±443
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1275 ± APS 1 Circuit Fault

StepActionValue(s)Ye sNo
1Was the ªOn-Board (OBD) System Checkº performed?
ÐGo to Step 2
Go to OBD
System
Check
2Was the ªElectric Throttle Control (ETC) System
Checkº performed?
ÐGo to Step 3
Go to ETC
System
Check
3Observe the AP angle reading on the Tech 2 while
slowly opening the throttle.
Does the AP angle increase steadily and evenly from
the closed throttle value to the wide open throttle
value?Idle position
=12 ~ 14 %
Wide open
throttle =86
~ 88 %
Refer to
Diagnostic
Aids
Go to Step 4
41. Disconnect the AP sensor.
2. Observe the AP sensor reading on the Tech 2.
Is the AP sensor reading near the specified value?
0VGo to Step 5Go to Step 6
51. Connect a test light between the 5 Volt supply circuit
and the AP1 sensor signal circuit at the AP sensor
harness connector.
2. Observe the AP sensor reading on the Tech 2.
Is the AP sensor reading near the specified value?
5VGo to Step 8Go to Step 7
6Check the following items;
1. AP1 signal circuit for a short to voltage.
2. AP1 sensor ground circuit for high resistance
between the PCM and the AP sensor.
3. AP1 sensor ground circuit for a poor connection.
4. If a problem is found, repair wiring harness as
necessary.
Was a problem found?
ÐVerify repairGo to Step 9
7Check the following items;
1. AP1 signal circuit or 5 volt supply circuit for a poor
connection.
2. AP1 signal circuit or 5 volt supply circuit for high
resistance between the PCM and the AP1 sensor.
3. If a problem is found, repair wiring harness as
necessary.
Was a problem found?
ÐVerify repairGo to Step 9
8Replace the AP sensor.
Is the action complete?
ÐVerify repairÐ
9Replace 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