check engine ISUZU AXIOM 2002 Service Repair Manual

6E±488
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
information included in the Failure Records data can
be useful in determining vehicle mileage since the
DTC was last set.If it is determined that the DTC occurs intermittently,
performing the DTC P1516 Diagnostic Chart may
isolate the cause of the fault.
DTC P1516 - Command - Actual TPS 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
31. 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 P1516.
Does the Tech 2 indicate DTC P1516 failed this
ignition?
ÐGo to Step 4
Refer to
Diagnostic
Aids
4Observe the TP angle reading on the Tech 2 while
slowly opening the throttle.
Does the TP angle increase steadily and evenly from
the closed throttle value to the wide open throttle
value?Closed
throttle TP
sensor 1 =8 ~
10 % TP
sensor 2 =90
~ 92 % Wide
open throttle
TP sensor 1
=90 ~ 92 %
TP sensor 2
=8 ~ 10 %
Go to Step 5Go to Step 8
51. Ignition ªOFFº.
2. Disconnect the DC motor.
Is the DC motor reading near the specified value?
0.3 ~ 100
Go to Step 6Go to Step 7
6Check the DC motor harness between the PCM and
DC Motor circuit at the DC motor harness connector.
Was a problem found?
ÐVerify repairGo to Step 8
7Replace the DC motor.
Is the action complete?
ÐVerify repairGo to Step 6
81. Disconnect the TP sensor.
2. Observe the TP sensor reading on the Tech2.
Is the TP sensor reading near the specified value?
0VGo to Step 9Go to Step 10
91. Connect a test light between the 5 Volt reference
circuit and the TP1 and TP2 sensor signal circuit at
the TP sensor harness connector.
2. Observe the TP sensor reading on the Tech 2.
Is the TP sensor reading near the specified value?
5VGo to Step 12Go to Step 11

6E±489
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1516 - Command - Actual TPS Correlation Error

 
StepNo Ye s Value(s) Action
10Check the following items;
1. TP1 and TP2 signal circuit for a short to voltage.
2. TP1 and TP2 sensor ground circuit for high
resistance between the PCM and the TP sensor.
3. TP1and TP2 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 13
11Check the following items;
1. TP1and TP2 signal circuit or 5 volt reference circuit
for a poor connection.
2. TP1 and TP2 signal circuit or 5 volt reference circuit
for high resistance between the PCM and the TP1
and TP2 sensor.
3. If a problem is found, repair wiring harness as
necessary.
Was a problem found?
ÐVerify repairGo to Step 13
12Replace the TP sensor.
Is the action complete?
ÐVerify repairÐ
13Replace 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±490
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1523 Actuator Control Return Performance
D06RY00111
Circuit Description

The throttle position (TP) sensor circuit provides a
voltage signal relative to throttle position (blade angle).
The throttle blade angle will vary from about 8 % at
closed throttle to about 92 % at wide open
throttle(WOT).

The DC motor circuit provides a voltage signal relative
to command throttle position (blade angle).

This DTC detects if the throttle return to the default
position at key on is steady.
Conditions for setting the DTC

The ignition is ªONº.

Normalized TPS is less than 7 % or Normalized TPS
is more than 25 %.
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 P1523 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.

DTC P1523 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
TP sensor 1, TP sensor 2 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 P1523 cannot be duplicated, the
information included in the Failure Records data can
be useful in determining vehicle mileage since the
DTC was last set.

6E±491
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
If it is determined that the DTC occurs intermittently,
performing the DTC P1523 Diagnostic Chart may
isolate the cause of the fault.
DTC P1523 - Actuator Control Return Performance

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 TP angle reading on the Tech 2 while
slowly opening the throttle.
Does the TP angle increase steadily and evenly from
the closed throttle value to the wide open throttle
value?Closed
throttle TP
sensor 1 =8 ~
10 % TP
sensor 2 =90
~ 92 % Wide
open throttle
TP sensor 1
=90 ~ 92 %
TP sensor 2
=8 ~ 10 %
Go to Step 4Go to Step 7
41. Ignition ªOFFº.
2. Disconnect the DC motor.
Is the DC motor reading near the specified value?
0.3 ~ 100
Go to Step 5Go to Step 6
5Check the DC motor harness between the PCM and
DC Motor circuit at the DC motor harness connector.
Was a problem found?
ÐVerify repairGo to Step 7
6Replace the DC motor.
Is the action complete?
ÐVerify repairGo to Step 5
71. Disconnect the TP sensor.
2. Observe the TP sensor reading on the Tech 2.
Is the TP sensor reading near the specified value?
0VGo to Step 8Go to Step 9
81. Connect a test light between the 5 Volt reference
circuit and the TP1 and TP2 sensor signal circuit at
the TP sensor harness connector.
2. Observe the TP sensor reading on the Tech 2.
Is the TP sensor reading near the specified value?
5VGo to Step 11Go to Step 10
9Check the following items;
1. TP1 and TP2 signal circuit for a short to voltage.
2. TP1 and TP2 sensor ground circuit for high
resistance between the PCM and the TP sensor.
3. TP1and TP2 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 12

6E±492
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1523 - Actuator Control Return Performance

 
StepNo Ye s Value(s) Action
10Check the following items;
1. TP1and TP2 signal circuit or 5 volt reference circuit
for a poor connection.
2. TP1 and TP2 signal circuit or 5 volt reference circuit
for high resistance between the PCM and the
TP1and TP2 sensor.
3. If a problem is found, repair wiring harness as
necessary.
Was a problem found?
ÐVerify repair
Go to Step 12
11Replace the TP sensor.
Is the action complete?
ÐVerify repairÐ
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

6E±493
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1571 Brake Switch No Operation
060R200067
Circuit Description
The brake switch has 3 functions.

Brake pedal operation check

Brake light operation (On and off)

Cruise control (Cancel)
The PCM receives vehicle speed and switch position
signals from the brake switch. The PCM sets brake
operating conditions in response to these signals.
If the brake switch is on, the brake system is in normal
operation (cruise control cancelled).
Conditions for Setting the DTC

Two break switch signals do not acknowledge after
signal changed.

Switch does not change during accelerating vehicle or
decelerating.

VSS is not fault.

Engine is running.
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 DTC

DTC P1571 can be cleared by using the scan tool
ªClear Infoº function or by disconnecting the PCM
battery feed.
Diagnostic Aids

Damaged harness±Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
fuel level display on the scan tool while moving
connectors and wiring harnesses related to the sensor.
A change in the display will indicate the location of the
fault.

6E±494
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1571 Brake Switch No Operation

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.
Engine ªOffº.
2. Check following fuses.

BACK 15A

STOP LAMP 15A
Was a problem found?
ÐVerify repairGo to Step 3
31. Make adjustment to the brake switch.
(Refer to
ªBrake switchº in ª10A CRUISE
CONTROL SYSTEMº.
)
Was the problem found?
ÐVerify repairGo to Step 4
41. Push the shaft on brake switch.
2. Check shaft operation for smooth movement.
Was the problem found?
ÐVerify repairÐ
51. Disconnect the connector at brake switch.
2. Check following terminal pin by ohmmeter.
(Leave the shaft position at brake switch. Don't
push it.)

Between pin 1 and pin 2

Between pin 3 and pin 4
Was it specified value?
Between pin1
and pin2 is
0
, Between
pin3 and pin4
is 8

Go to Step 6Go to Step 9
61. Disconnect the connector at brake switch.
2. Check following terminal pin at ohmmeter.
(Don't press the button of the brake switch.)

wBetween pin 1 and pin 2

wBetween pin 3 and pin 4
Was it specified value?
Between pin1
and pin2 is
8
, Between
pin3 and pin4
is 0

Go to Step 7Go to Step 9
71. Probe related circuits for open or short to ground.
2. If a problem was found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 8
81. Replace 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.
Was the action completed?
ÐVerify repairÐ
91. Replace the brake switch.
Was the action completed?
ÐVerify repairÐ

6E±495
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1625 PCM Unexpected Reset
Circuit Description
The powertrain control module (PCM) monitors
unexpected PCM reset. This will not turn on MIL light on,
only record code DTC P1625.
Conditions for Setting the DTC

Clock or COP (Computer Operating Properly) reset.
Action Taken When the DTC Sets

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

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 P1625 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P1625 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids
Check for the following conditions:

P1625 stored alone does not need diagnosis. Clear
DTC code.
DTC P1625 ± PCM Unexpected Reset

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition is ªONº.
2. Install the Tech 2.
3. Start the engine and let it Idle.
4. On the Tech 2, select ªDTC infoº.
Does the Tech 2 indicate DTC P1625 failed?
ÐGo to Step 3
Go to
Diagnostic
Aids
31. Ignition is ªONº.
2. Clear DTC P1625 by using the Tech 2 ªClear Infoº.
3. Start the engine and let it Idle.
4. On the Tech 2, select ªDTC infoº.
Does the Tech 2 indicate DTC P1625 failed?
ÐGo to Step 4
Go to
Diagnostic
Aids
41. Check for aftermarket electronics, such as
transceiver, stereos, and anti theft devices. They
may radiate EMI into the control system if they are
improperly installed. (This may cause a false sensor
reading and turn on the MIL.)
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairÐ

6E±497
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1635 Reference Voltage # 1 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 not running.
2. Using a DVM at the PCM side of the connector,
check the voltage at terminal S38 (RED) pin.
Is the voltage in specified range?
4.95 ± 5.0V
Go to ETC
System
Check
Go to Step 3
31. Ignition ªONº, engine not running.
2. Using a DVM at the PCM side of the connector,
check the voltage at terminal F20 (RED/WHT) pin.
Is the voltage in specified range?
11.6 ± 12.7VGo to Step 4 Go to Step 5
41. Ignition ªONº, engine not running.
2. Using a DVM at the PCM side of the connector,
check the voltage at terminal F57 (RED/WHT) pin.
Is the voltage in specified range?
11.6 ± 12.7VGo to Step 6 Go to Step 5
5Observe the battery voltage and circuit. If a problems
found, repair it as necessary.
Was the problem found?
ÐVerify repairGo to Step 6
6Replace 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±499
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1639 Reference Voltage # 2 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 not running.
2. Using a DVM at the PCM side of the connector,
check the voltage at terminal S36 (BLK) pin.
Is the voltage in specified range?
4.95 ± 5.0V
Go to ETC
System
Check
Go to Step 3
31. Ignition ªONº, engine not running.
2. Using a DVM at the PCM side of the connector,
check the voltage at terminal F20(RED/WHT) pin.
Is the voltage in specified range?
11.6 ± 12.7VGo to Step 4 Go to Step 5
41. Ignition ªONº, engine not running.
2. Using a DVM at the PCM side of the connector,
check the voltage at terminal F57 (RED/WHT) pin.
Is the voltage in specified range?
11.6 ± 12.7VGo to Step 6 Go to Step 5
5Observe the battery voltage and circuit.
If a problem is found, repair it as necessary.
Was the problem found?
ÐVerify repairGo to Step 6
6Replace 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