Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 365

6E–490

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) 

P1523 Actuator Control Return Performance

D06RY00111

Circuit Description

D

The throttle position (TP) sensor circuit provides a
voltage signal relative to throttle position (blade angle).
The throttle blade angle will vary from about 8 % at
closed throttle to about 92 % at wide open
throttle(WOT).

D

The DC motor circuit provides a voltage signal relative
to command throttle position (blade angle).

D

This DTC detects if the throttle return to the default
position at key on is steady.

Conditions for setting the DTC

D

The ignition is “ON”.

D

Normalized TPS is less than 7 % or Normalized TPS
is more than 25 %.

Action Taken When the DTC Sets

D

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

D

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

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 P1523 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.

D

DTC P1523 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 connections.

D

Misrouted 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
TP sensor 1, TP 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 P1523 cannot be duplicated, the
information included in the Failure Records data can
be useful in determining vehicle mileage since the
DTC was last set.

6E–491

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

If it is determined that the DTC occurs intermittently,
performing the DTC P1523 Diagnostic Chart may
isolate the cause of the fault.

DTC P1523 - Actuator Control Return Performance

 

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 TP angle reading on the Tech 2 while
slowly opening the throttle.

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

Closed

throttle TP

sensor 1 =8 

∼

10 % TP

sensor 2 =90

∼

 92 % Wide

open throttle

TP sensor 1

=90 

∼

 92 %

TP sensor 2

=8 

∼

 10 %

Go to

 Step 4

Go to

 Step 7

4

1. Ignition “OFF”.
2. Disconnect the DC motor.

Is the DC motor reading near the specified value?

0.3 

∼

 100 

W

Go to

 Step 5

Go to

 Step 6

5

Check the DC motor harness between the PCM and
DC Motor circuit at the DC motor harness connector.

Was a problem found?

—

Verify repair

Go to

 Step 7

6

Replace the DC motor.

Is the action complete?

—

Verify repair

Go to

 Step 5

7

1. Disconnect the TP sensor.
2. Observe the TP sensor reading on the Tech 2.

Is the TP sensor reading near the specified value?

0V

Go to

 Step 8

Go to

 Step 9

8

1. Connect a test light between the 5 Volt reference

circuit and the TP1 and TP2 sensor signal circuit at
the TP sensor harness connector.

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

Is the TP sensor reading near the specified value?

5V

Go to

 Step 11

Go to

 Step 10

9

Check the following items;

1. TP1 and TP2 signal circuit for a short to voltage.
2. TP1 and TP2 sensor ground circuit for high

resistance between the PCM and the TP sensor.

3. TP1and TP2 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 12

6E–492

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

DTC P1523 - Actuator Control Return Performance

  (Cont'd)

Step

No

Yes

Value(s)

Action

10

Check the following items;

1. TP1and TP2 signal circuit or 5 volt reference circuit

for a poor connection.

2. TP1 and TP2 signal circuit or 5 volt reference circuit

for high resistance between the PCM and the
TP1and TP2 sensor.

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

necessary.

Was a problem found?

—

Verify repair

Go to

 Step 12

11

Replace the TP sensor.

Is the action complete?

—

Verify repair

—

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 replacement PCM.

Is the action complete?

—

Verify repair

—

6E–493

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P1571 Brake Switch No Operation

060R200067

Circuit Description

The brake switch has 3 functions.

D

Brake pedal operation check

D

Brake light operation (On and off)

D

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

D

Two break switch signals do not acknowledge after
signal changed.

D

Switch does not change during accelerating vehicle or
decelerating.

D

VSS is not fault.

D

Engine is running.

Action Taken When the DTC Sets

D

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

D

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

D

DTC P1571 can be cleared by using the scan tool
“Clear Info” function or by disconnecting the PCM
battery feed.

Diagnostic Aids

D

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.