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Isuzu Trooper (1998-2002 year). Manual - part 507

6E–398

6VE1 3.5 ENGINE DRIVEABILITY AND EMISSIONS

DTC P1285 – APS 3 Circuit Fault

Step

Action

Value(s)

Yes

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

—

Go to

Step 2

Go to

OBD

System

Check

1. Warming up the engine until the ECT rise at 80

2. Ignition “OFF”.
3. Ignition ON” but not engine run.
4. Observe the AP angle reading on the Tech 2 while

alowly opening the throttle.

Does the AP angle increase steadily and evenly from
the closed throttle value to the wide open throttle
value?

Closed

throttle APS3

= 85

∼

89%

Wide open

throttle APS3

= 32

∼

36%

Go to

Step 3

Go to

Step 4

Was the DTC P1285 stored?

—

Go to

Step 8

Check the

procedure.

Refer to

Diagnostic

Aids

1. Connect a test light between the 5 Voltge supply

circuit and the AP3 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?

Go to

Step 5

Go to

Step 6

1. Check the following items;

AP3 signal circuit for a short to voltage.

2. AP3 sensor ground circuit for high resistance

between the PCM and the AP sensor.

3. AP3 sensor ground circuit for a poor connection.
4. If a problem is found, repair wiring harness as

necessary.

Was a problem found?

—

Verify repair

Go to

Step 6

Check the following items;

1. AP3 signal circuit or 5 volge supply circuit for a poor

connection.

2. AP3 signal circuit or 5 volge supply circuit for high

resistance between the PCM and the AP3 sensor.

3. If a problem is found, repair wiring harness as

necessary.

Was a problem found?

—

Verify repair

Go to

Step 7

Replace the AP sensor.

Was a problem corrected

—

Verify repair

Go to

Step 8

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 ornot.

And then Down Load the LATEST PROGRAMMED
SOFTWARE to the replasement PCM.

Is the action complete?

—

Verify repair

—

6E–399

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P1290 ETC Forced Idle Mode

D06RY00157

Circuit Description

The acceleration position (AP) sensor circuit provides
a voltage signal relative to acceleration pedal angle.
The acceleration pedal angle (AP1) will vary about
13 % at idle position to about 87 % at wide open
throttle (WOT).

This code detects that if the systm is in Forced Idle
Mode. (Fail safe Mode)

Conditions for setting the DTC

The Ignition is “ON”.

Forced Idle Mode is active. (Fail safe Mode)

Action Taken When the DTC Sets

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 “OFF” on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condtion is no longer present.

A history DTC P1290 will clear after 40 cosecutive trip
cycle during which the warm up cycles have occurred
without a fault.

DTC P1290 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.

Mis routed 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, APP sensor 2, APP 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 P1290 cannot be duplicated, the
information included in the Faillure 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

P1290 Diagnostic Chart may isolate the cause of the
fault.

6E–400

6VE1 3.5 ENGINE DRIVEABILITY AND EMISSIONS

DTC P1290 - ETC Forced Idle Mode

Step

Action

Value(s)

Yes

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

—

Go to

Step 2

Go to

OBD

System

Check

1. Check for a poor conection at the AP1,AP2,AP3

sensor harness conector.

2. If a problem found, repair as necessary.

Was a problem found ?

—

Verify repair

Go to

Step 3

1. Check the curcuit between the PCM and each

terminal of AP1,AP2 and AP3 sensor.

2. If the curcuit is open or shorted, repair it as

necessary.

Was the curcuit open or short?

—

Vefiry repair

Go to

Step 4

Replace the AP sensor.

Is the action complate?

—

Go to

Step 5

—

1. Warming up the engine until the ECT rise at 80

2. Ignition “OFF”.
3. Ignition ON” but not engine run.
4. Observe the AP angle reading on the Tech 2 while

alowly opening the throttle.

Does the AP angle increase steadily and evenly from
the closed throttle value to the wide open throttle
value?

Closed

throttle APS1

= 11

∼

15%

APS2 =

∼

89%

APS3 =

∼

89% Wide

open throttle

APS1 =

∼

89 APS2

= 11

∼

15%

APS3 =

∼

36%

—

Go to

Step 6

Replace the PCM;

The replacement PCM must be programmed. Refer to
ON–Vehicle Service in Power Control Module and Sen-
sors 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 replasement PCM.

Is the action complate?

—

Verify repair

—

6E–401

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P1295 Power Management Mode

D06RY00088

Circuit Description

The throttle position (TP) sensor circuit provides a
voltage signal relative to throttle position (blade angle).
The throttle blade angle will vary 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).

The mass air flow (MAF) sensor measures the amount
of air which passes through it into the engine during a
given time. The powertrain Control Module (PCM)
uses the mass air flow information to monitor engine
operating conditions for fuel delivery calculations.
A large quantitiy of air entering the engine indicates
an accleration or high load situation, while a small
quantity or air indicates deceleration or idle.

The MAF sensor produces a frequency signal which
can be monitored using a Tech 2. The frequency will
vary within a range of around 4 to 7g/s at idle to
around 25 to 40g/s at maximum engine load.

This DTC ditects that if the systm is in
PowerManagement Mode.(Fail safe Mode)

Conditions for setting the DTC

The ignition is “ON”.

Power Management Mode is active. (Fail safe Mode)

Action Taken When the DTC Sets

The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.

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 “OFF” on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condtion is no longer present.

A history DTC P1295 will clear after 40 cosecutive trip
cycle during which the warm up cycles have occurred
without a fault.

DTC P1295 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 connectons.

Mis routed 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

Content .. 505 506 507 508 ..