Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 354

6E–446

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P1285 APS 3 Output Fault

060R200064

Circuit Description

The accelerator position (AP) sensor circuit provides a
voltage signal relative to accelerator pedal angle.
The accelerator pedal sensor (AP3) will vary from
about 87 % at idle position to about 34 % 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 “ON”.

The accelerator pedal sensor 3 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 the 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 “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 P1285 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.

DTC P1285 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
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 P1285 cannot be duplicated, the
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

P1285 Diagnostic Chart may isolate the cause of the
fault.

6E–447

6VE1 3.5L 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

Was the “Electric Throttle Control (ETC) System
Check” performed?

—

Go to

Step 3

Go to

ETC

System

Check

Observe 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

=86

∼

%Wide open

throttle =32

∼

36 %

Refer to

Diagnostic

Aids

Go to

Step 4

1. Disconnect the AP sensor.
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. Connect a test light between the 5 volt 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 8

Go to

Step 7

Check the following items;

1. 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 9

Check the following items;

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

connection.

2. AP3 signal circuit or 5 voltage 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 9

Replace the AP sensor.

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–448

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P1290 ETC Forced Idle Mode

060R200069

Circuit Description

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

This code detects that if the system 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 illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.

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 “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 P1290 will clear after 40 consecutive trip
cycles 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
AP sensor 1, 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 P1290 cannot be duplicated, the
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

P1290 Diagnostic Chart may isolate the cause of the
fault.

6E–449

6VE1 3.5L 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

Was the “Electric Throttle Control (ETC) System
Check” performed?

—

Go to

Step 3

Go to

ETC

System

Check

Observe 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?

Idle position

AP sensor 1

=12

∼

14 %

AP sensor 2,

3 =86

∼

88 %

Wide open

throttle AP

sensor 1 =86

∼

88 % AP

sensor 2 =12

∼

14 % AP

sensor 3 =32

∼

36 %

Refer to

Diagnostic

Aids

Go to

Step 4

1. Disconnect the AP sensor.
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. Connect a test light between the 5 voltage supply

circuit and the AP1, AP2 and AP3 sensor signal
circuit at the AP sensor harness connector.

2. Observe the AP sensor reading on the Tech2.

Is the AP sensor reading near the specified value?

Go to

Step 8

Go to

Step 7

Check the following items;

1. AP1,AP2 and AP3 signal circuit for a short to

voltage.

2. AP1, AP2 and AP3 sensor ground circuit for high

resistance between the PCM and the AP sensor.

3. AP1, 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?

—

Verify repair

Go to

Step 9

Check the following items;

1. AP1, AP2 and AP3 signal circuit or 5 volt supply

circuit for a poor connection.

2. AP1, AP2 and AP3 signal circuit or 5 volt supply

circuit for high resistance between the PCM and the
AP1, AP2 and AP3 sensor.

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

necessary.

Was a problem found?

—

Verify repair

Go to

Step 9

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