Content .. 485 486 487 488 ..

Isuzu Trooper (1998-2002 year). Manual - part 487

6E–318

6VE1 3.5 ENGINE DRIVEABILITY AND EMISSIONS

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 Cruise
resume switch 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 P0567 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 DTCP0567 Diagnostic Chart may
isolate the cause of the fault.

DTC P0567 Cruise Resume Switch Circuit Error

Step

Action

Value(s)

Yes

Was the “On-Board (OBD) System Check” performed?

—

Go to

Step 2

Go to

OBD

System

Check

Check the signal circuit for auto cruise resume switch.

1. Ignition is “OFF”.
2. Disconnect the powertrain control module (PCM).
3. Disconnect the cruise resume switch. Check for

cruise resume switch signal circuit between the
PCM and the cruise resume switch.

Is a problem found?

Go to

Step 3

Go to

Step 4

Repair the main cruise resume switch signal circuit.

Is the action complete?

—

Verify repair

—

Check the auto cruise resume switch.

Is a problem found?

—

Go to

Step 5

Go to

Step 6

Repair or replace the main cruise resume switch.

Is the action complete?

—

Verify repair

—

Replace 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?

—

Verify repair

—

6E–319

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC)

P0568 Cruise Set Switch Circuit Error

D06R200090

Circuit Description

The cruise control keeps the vehicle running at a fixed
speed until a signal canceling this fixed speed is received.
When the main switch is turned on with the vehicle in the
running mode, the battery voltage is applied to powertrain
control module (PCM). When a signal from the control
switch is input to PCM while the vehicle is in this state, the
cruise control system is activated. Also, while the PCM is
operating, the “CRUISE MAIN” indicator light in the meter
assembly lights up.
When the set switch is “ON”, vehicle speed is set.

Conditions for setting the DTC

The Ignition is “ON”.

Engine is running.

System voltage is between 11.5 volts and 16 volts.

The switch contact remain on for 120 seconds or more.

Noises are generated by poor switch contact 100 times
within 1.6 seconds.

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 in the Failure Records data only.

Conditions for Clearing the MIL/DTC

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

A history DTC P0568 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.

6E–320

6VE1 3.5 ENGINE DRIVEABILITY AND EMISSIONS

DTC P0568 can be cleared using the Tech 2 “Clear
Info” 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
cruise set switch 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 P0568 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 DTCP0568 Diagnostic Chart may
isolate the cause of the fault.

DTC P0568 Cruise Set Switch Circuit Error

Step

Action

Value(s)

Yes

Was the “On-Board (OBD) System Check” performed?

—

Go to

Step 2

Go to

OBD

System

Check

1. Ignition “ON,” engine “ON.”
2. Observe the cruise indicator lamp in the meter.

Is the cruise indicator lamp “ON?”

—

Go to

Step 3

Go to

Step 4

1. Push the auto cruise set switch.
2. Observe the cruise indicator lamp in the meter.

Is the cruise indicator lamp “OFF ?”

—

Check the

Procedure

Refer to

Diagnostic

Aids

Go to

Step 5

Check the signal circuit for auto cruise set switch.

1. Ignition is “OFF”.
2. Disconnect the powertrain control module (PCM).
3. Disconnect the cruise set switch.

Check for cruise set switch signal circuit between
the PCM and the cruise set switch.

Is a problem found?

Go to

Step 5

Go to

Step 6

Repair the main cruise set switch signal circuit.

Is the action complete?

—

Verify repair

—

Check the auto cruise set switch.

Is a problem found?

—

Go to

Step 7

Go to

Step 8

Repair or replace the main cruise set switch.

Is the action complete?

—

Verify repair

—

Replace 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?

—

Verify repair

—

6E–321

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P0571 No Brake Switch Signal

D06R200076

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 brake switch signals not acknowledged after
signal changed.

VSS not defective.

Engine is running.

Vehicle speed above 20km/h.

Action Taken When the DTC Sets

The PCM will not turn the malfunction indicator lamp
(MIL) “ON”.

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 P0571 can be cleared by using the scan tool
“Clear Info” 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.

Content .. 485 486 487 488 ..