Isuzu Trooper (1998-2002 year). Manual - part 624

6E–144

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P1485 (Flash DTC 74) 

ITP (Intake Thorottle Position) Sensor Low Voltage

060RW134

Circuit Description

The intake throttle position (ITP) sensor circuit provides a
voltage signal that changes relative to throttle blade
angle.

Action Taken When the DTC Sets

D

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

D

The ECM 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

D

DTC P1485 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the ECM battery
feed.

Diagnostic Aids

Check for the following conditions:

D

Poor connection at ECM – 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
throttle position display on the Tech 2 while
moving connectors and wiring harnesses related
to the ITP sensor.  A change in the display will
indicate the location of the fault.

If DTC P1485 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.

DTC P1485 –ITP Sensor Low Voltage

 

Step

Action

Value(s)

Yes

No

1

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

—

Go to 

Step 2

Go to 

OBD

System

Check

2

1. Ignition “ON,” engine “OFF.”
2. With the throttle closed by the hand, observe the

“ITP Sensor” display on the Tech 2.

Is the “ITP Sensor” below the specified value?

0.22 V

Go to 

Step 4

Go to 

Step 3

6E–145

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

DTC P1485 –ITP Sensor Low Voltage

  (Cont'd)

Step

No

Yes

Value(s)

Action

3

1. Ignition “ON,” engine “OFF.”
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor the “DTC” info for DTC

P1485.

Does the Tech 2 indicate DTC P1485 failed?

—

Go to 

Step 4

Refer to

Diagnostic

Aids

4

Check the ITP sensor signal circuit for a poor
connection at the ECM and replace the terminal if
necessary.

Did the terminal require replacement?

—

Verify repair

Go to 

Step 5

5

1. Ignition “ON,” engine “OFF.”
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2 monitor the “Specific DTC” info for

DTC P1485.

Dose the Tech 2 indicate DTC P1485 failed?

—

Go to 

Step 6

Refer to

Diagnostic

Aids

6

Replace the intake throttle.

Is the action complete?

—

Verify repair

Go to 

Step 7

7

Replace the ECM (Refer to the Data Programming in
Case of ECM change).

Is the action complete?

—

Verify repair

—

6E–146

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P1486 (Flash DTC 74) 

ITP (Intake Throttle Position) Sensor High Voltage

060RW134

Circuit Description

The intake throttle position (ITP) sensor circuit provides a
voltage signal that changes relative to throttle blade
angle.

Action Taken When the DTC Sets

D

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

D

The ECM 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

D

DTC P1486 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the ECM battery
feed.

Diagnostic Aids

Check for the following conditions:

D

Poor connection at ECM – 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
ITP sensor display on the Tech 2 while moving
connectors and wiring harnesses related to the TP
sensor.  A change in the display will indicate the
location of the fault.

D

Faulty TP sensor – With the ignition key “ON,” engine
“OFF,” observe the TP sensor display on the Tech 2
while slowly depressing the accelerator to wide open
throttle.

If DTC P1486 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–147

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

DTC P1486 – ITP Sensor High Voltage

 

Step

Action

Value(s)

Yes

No

1

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

—

Go to 

Step 2

Go to 

OBD

System

Check

2

1. Ignition “ON,” engine “OFF.”
2. With the throttle closed by the hand, observe the

“ITP Sensor” display on the Tech 2.

Is the “ITP Sensor” above the specified value?

4.88 V

Go to 

Step 4

Go to 

Step 3

3

1. Ignition “ON,” engine “OFF.”
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor “DTC” info for DTC P1486.

Does the Tech 2 indicate DTC P1486 failed.

—

Go to 

Step 4

Refer to

Diagnostic

Aids

4

Check for poor electrical connections at the ITP sensor
and replace terminals if necessary.

Did any terminals require replacement?

—

Verify repair

Go to 

Step 5

5

1. Ignition “ON,” engine “OFF.”
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2 monitor the “DTC” info for DTC

P1486.

Dose the Tech 2 indicate DTC P1486 failed.

—

Go to 

Step 6

Refer to

Diagnostic

Aids

6

Replace the intake throttle.

Is the action complete?

—

Verify repair

Go to 

Step 7

7

Replace the ECM (Refer to the Data Programming in
Case of ECM change).

Is the action complete?

—

Verify repair

—