ISUZU AXIOM 2002 Service Repair Manual

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±496
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1635 Reference Voltage # 1 Circuit Fault
D06RY00093
Circuit Description
The TP sensor # 1 shares a 5 Volt reference with the
PCM.
If the PCM detects the 5 Volt reference for the TP sensor #
1 is failure, DTCP1635 will be set.
Conditions for setting the DTC

The ignition is ªONº.

The 5 Volt reference voltage for the TP sensor # 1 is
less than 4 volts.

The 5 Volt reference voltage for the TP sensor # 1 is
more than 5 volts.
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 P1635will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.

DTC P1635 can be cleared using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed. Tech2 ª Clear Infoº function or by disconnecting
the PCM battery feed.

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±498
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1639 Reference Voltage # 2 Circuit Fault
060R200064
Circuit Description
The AP sensor # 1shares a 5 Volt reference with the PCM.
If the PCM detects the 5 Volt reference for the AP sensor
# 1 is failure, DTC P1635 will be set.
Conditions for setting the DTC

The ignition is ªONº.

The 5 Volt reference voltage for the AP sensor # 1 is
less than 4 volts.

The 5 Volt reference voltage for the AP sensor # 1 is
more than 5 volts.
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 P1639 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.

DTC P1639 can be cleared using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed. Tech 2 ªClear Infoº function or by disconnecting
the PCM battery feed.

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

6E±500
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1640 Driver-1-Output Circuit Fault (ODM)
Circuit Description
Output driver modules (ODMs) are used by the
powertrain control module (PCM) to turn ªONº many of
the current-driven devices that are needed to control
various engine and transmission functions. Each ODM is
capable of controlling up to 7 separate outputs by
applying ground to the device which the PCM is
commanding ªONº.
Unlike the Quad Driver Modules (QDMs) used in prior
model years, ODMs have the capability of diagnosing
each output circuit individually. DTC P1640 set indicates
an improper voltage level has been detected on an ODM
output.
Since A/C is an option, No A/C will cause the air
conditioning clutch relay output to always fail. If a fault is
seen on the air conditioning clutch relay output, it will not
be logged as a fault until the A/C request input interrupts a
high voltage, indicating that A/C has been installed.
Conditions for Setting the DTC

Ignition ªONº.

Engine running.

Ignition voltage is above 13.2 volts for 4 seconds.

Output voltage does not equal ignition voltage when
output is ªOFFº or output voltage is not less than 1 volt
when output is ªONº.

Above conditions occur for at least 1 second.
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

A history DTC P1640 will clear after 40 consecutive
warm-up cycles occur without a fault.

DTC P1640 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:

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, disconnect
the PCM, turn the ignition ªONº and observe a
voltmeter connected to the suspect driver circuit at the
PCM harness connector while moving connectors and
wiring harnesses related to the MIL. A change in
voltage will indicate the location of the fault.

Poor connection at component ± Examine for
damaged connectors, unplugged connector, or
damaged terminals at the following locations:
Instrument cluster harness, canister purge solenoid,
A/C clutch relay. An open ignition feed circuit at any of
these components will cause DTC P1640 to be set.
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.
4. The Tech 2 Driver Module Status indicates the PCM
pin that is affected.
9. The Tech 2 may indicate ªshort circuitº even when
the problem is an open circuit. The cause of an
open circuit may be in the component itself-lamp,
purge, solenoid, or A/C compressor relay.
11.A short to ground on the ignition side of the
component will blow the fuse. Since the fuse was
checked in Step 2, a short to ground would be
between the affected component and the PCM.

6E±501
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1640 ± Driver-1-Output Circuit Fault (ODM)

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Check the fuse for the driver circuit that was shown as
faulty.
Was the fuse blown?
ÐGo to Step 3Go to Step 4
31. Check for a short to ground between the fuse and
the affected component.
2. Replace the fuse after making any necessary
repairs.
Is the action complete?
ÐVerify repairÐ
4Disconnect the PCM connector for the affected driver
circuit.
Is there any damage to the PCM pin or connector?
ÐGo to Step 5Go to Step 6
5Repair the damaged pin or terminal.
Is the action complete?
ÐVerify repairÐ
6Were either of the lamp circuits for ªCheck Engineº or
ªCheck Transº indicated as faulty by the Tech 2?
ÐGo to Step 7Go to Step 13
71. Leave the PCM connector for the lamp driver circuit
disconnected.
2. Ignition ªONº.
3. Using a DVM, check the voltage at the PCM
connector for the affected lamp driver circuit.
Was the voltage equal to the specified value?
B+Go to Step 15Go to Step 8
81. Ignition ªONº.
2. Check for battery voltage at the fuse for the affected
lamp circuit.
Was battery voltage available at the fuse?
ÐGo to Step 10Go to Step 9
9Repair the open circuit between the ignition switch and
the fuse.
Is the action complete?
ÐVerify repairÐ
101. Ignition ªOFFº.
2. Disconnect the PCM connector for the affected
driver terminal.
3. Connect an ohmmeter between a good ground and
the PCM connector for the affected driver.
Did the ohmmeter indicate continuity?
ÐGo to Step 11Go to Step 12
11Repair the short to ground between the affected
component and its PCM driver terminal.
Is the action complete?
ÐVerify repairÐ
12Repair the open circuit between the fuse and the PCM
driver terminal for the affected circuit.
Is the action complete?
ÐVerify repairÐ

6E±502
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1640 ± Driver-1-Output Circuit Fault (ODM)

 
StepNo Ye s Value(s) Action
131. Connect the PCM.
2. Start the engine and let it idle.
3. Backprobe the affected terminal at the PCM with a
DVM.
Was the voltage equal to the specified value?
+BGo to Step 15Go to Step 14
141. Run the engine at idle.
2. Check for battery voltage at the fuse for the affected
circuit.
Was battery voltage available at the fuse?
ÐGo to Step 10Go to Step 9
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 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±503
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1650 Quad Driver Module ªAº Fault
Circuit Description
The Quad Driver Module (QDMs) are used by the
powertrain control module (PCM) to turn ªONº
current±driven devices that are needed to control two
engine functions. The PCM monitors open or short circuit
of either of Canister Control Purge (CCP) Vent solenoid or
Variable Intake Manifold (VIM).
Conditions for Setting the DTC

Ignition ªONº.

Engine running.

Ignition voltage.

Output voltage does not equal voltage and is not less
than 1 volt when out put is ªONº.

Above conditions occur for at least 0.5 second.
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 P1650 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P1650 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:

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, disconnect
the PCM, turn the ignition ªONº and observe a
voltmeter connected to the suspect driver circuit at the
PCM harness connector while moving connectors and
wiring harnesses relates to the MIL. A change in
voltage will indicate the location of the fault.

Poor connection at component ± Examine for
damaged connectors, unplugged connector, or
damaged terminals at the following locations: canister
purge solenoid, fuel level sensor. An open ignition feed
circuit at any of these components will cause DTC
P1650 to be set.
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.
The following PCM pins are controlled by
Quad driver modules (QDMs):

S74 ± VIM

S48 ± Canister control purge
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
4. The Tech 2 Driver Module Status indicates the PCM
pin that is affected.
9.The Tech 2 may indicate ªshort circuitº even when the
problem is an open circuit. The cause of an open
circuit may be in the component itself.
11.A short to ground on the ignition side of the
component will blow the fuse. Since the fuse was
checked in Step 2, a short to ground would be
between the affected component and the PCM.