Isuzu Trooper (2000 year). Service manual - part 323

6E–421

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

 Diagnosis Truble Code(DTC) 

P1221 TPS1 – TPS2 correlation(Circuit Perfoemance)

  (Cont'd)

Step

No

Yes

Value(s)

Action

7

Replace the throttle valve.

Is the action complete?

—

Go to 

Step 4

—

8

1. Check the following circuits for an open, short to

voltage, short to ground, or poor connection at the
PCM:

D

Acceleration position sensor 1 circuit.

D

Acceleration position sensor 2 circuit.

D

C position sensor 3 circuit.

D

V position sensor resistance.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 9

9

Replace the acceleration position sensor.

Is the action complete?

—

Go to 

Step 10

—

10

Following  below the DTCs stored:
P1125, P1290, P1295, P1299

—

Go to

applicable
DTC table

Go to 

Step 11

11

Following  below the DTCs stored:
P1514, P1515, P1516, P1523, P1271, P1272, P1273

—

Go to

applicable
DTC table

Go to 

Step 12

12

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 replasement PCM.

Is the action complete?

—

Verify repair

—

6E–422

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P1271  APS 1– 2  Correlation Error

D06RY00075

Circuit Description

D

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 a correlation error between
APS1 and APS2.

Conditions for setting the DTC

D

The Ignition is “ON”.

D

The acceleration pedal angle difference is less than 4.5
% between ASP1 and APS2 for 50 counts within 50
test samples (15.6 m sec).

Action Taken When the DTC Sets

D

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

D

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.

D

A history DTC P1271 will clear after 40 consecutive trip
cycle during which the warm up cycles have occurred
without a fault.

D

DTC P1271 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:

D

Poor connectons.

D

Mis routed harness.

D

Rubbed through wire insulation.

D

Broken wire inside the insulation.

Check for the following conditions:

D

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.

D

Damaged harness-Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
APP sensor 1, APP 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 P1271 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 DTCP1271
Diagnostic Chart may isolate the cause of the
fault.

6E–423

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

DTC P1271 – APS 1– 2 Correlation Error

 

Step

Action

Value(s)

Yes

No

1

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

—

Go to

 Step 2

Go to

 OBD

System

Check

2

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

—

Go to 

Step 3

Go to 

ETC

System

Check

3

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

APP sensor 1

=13 % APP

sensor 2 =85

∼

 89 % Wide

open throttle

APP sensor 1

=85 

∼

 89 %

APP sensor 2

=11 

∼

 15 %

Refer to

Diagnostic

Aids

Go to

 Step 4

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?

0V

Go to

 Step 5

Go to

 Step 6 

5

1. Connect a test light between the 5 Voltge supply

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

2. Observe the AP sensor reading on the Tech 2.

Is the AP sensor reading near the specified value?

5V

Go to

 Step 7

Go to

 Step 8

6

Check the following items;

1. AP1and AP2 signal circuit for a short to voltage.
2. AP1and AP2 sensor ground circuit for high

resistance between the PCM and the AP sensor.

3. AP1and AP2 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 

7

Check the following items;

1. AP1and AP2 signal circuit or 5 volge supply circuit

for a poor connection.

2. AP1and AP2 signal circuit or 5 volge supply circuit

for high resistance between the PCM and the AP1
and AP2 sensor.

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

necessary.

Was a problem found?

—

Verify repair

Go to

 Step 9 

8

Replace the AP sensor.

Is the action complete?

—

Verify repair

—

6E–424

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

DTC P1271 – APS 1– 2 Correlation Error

  (Cont'd)

Step

No

Yes

Value(s)

Action

9

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

—