Isuzu Trooper (1998-2002 year). Manual - part 602

6E–56

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P0107 (Flash DTC 34)

MAP Sensor Circuit Low Voltage

060RW134

Circuit Description

The manifold absolute pressure (MAP) sensor responds
to changes in intake manifold pressure (vacuum).
The ECM monitors the MAP signals for voltages outside
the normal range of the MAP sensor. If the ECM detects a
MAP signal voltage that is excessively low, DTC P0107
will be set.

Action Taken When the DTC Sets

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

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

DTC P0107 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:

Turn on the ignition switch and stop the engine. At this
time, the boost pressure will be equal to the
atmospheric pressure and the signal voltage will
increase.

Check for intermittent codes.

The MAP sensor shares a ground with the ECT sensor,
and the Transmission Fluid Temperature sensor.

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.

Damaged harness – Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
MAP 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 P0107 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 P0107 Diagnostic Chart may isolate
the cause of the fault.

6E–57

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

DTC P0107 – MAP Sensor Circuit Low Voltage

Step

Action

Value(s)

Yes

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

—

Go to

Step 2

Go to

OBD

System

Check

Put the engine into an idling status.

Is the MAP voltage value displayed on the Tech 2 below
the specified value?

0.25 V

Go to

Step 3

Refer to

Diagnostic

Aids and

Symptom

Diagnosis

1. Turn off the ignition switch.
2. Remove the sensor connector connection.
3. Jumper between harness pins “red” and “blue”

wires.

4. Turn on the ignition switch “ON”.

Is the MAP voltage reading above the specified value?

4 V

Go to

Step 5

Go to

Step 4

1. Turn off the ignition switch.
2. Remove the jumper wire.
3. Connect the relay & solenoid checker

(5-8840-0386-0) to the battery voltage, then check
the MAP signal circuit (blue wire).

4. Turn on the ignition switch.

Is the value displayed on the Tech 2 above the specified
value?

4 V

Go to

Step 6

Go to

Step 7

Check the terminal connection at the MAP sensor and
repair or replace terminal if necessary.

Is the action complete?

—

Verify repair

—

Repair the 5V power circuit (red) harness or Replace
the ECM (Refer to the Data Programming in Case of
ECM change).

Is the action complete?

—

Verify repair

—

Repair the signal circuit (blue) harness or Replace the
ECM (Refer to the Data Programming in Case of ECM
change).

Is the action complete?

—

Verify repair

—

6E–58

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P0108 (Flash DTC 34)

MAP Sensor Circuit High Voltage

060RW134

Circuit Description

Action Taken When the DTC Sets

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

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

DTC P0108 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:

Turn on the ignition switch and stop the engine. At this
time, the boost pressure will be equal to the
atmospheric pressure and the signal voltage will
increase.

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.

If DTC P0108 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.

6E–59

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

Sensor Circuit High Voltage

Step

Action

Value(s)

Yes

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

—

Go to

Step 2

Go to

OBD

System

Check

Put the engine into an idling status.

Is the MAP voltage value displayed on the Tech 2
above the specified value?

4 V

Go to

Step 3

Go to

Step 4

1. Turn off the ignition switch.
2. Remove the sensor connector connection.
3. Turn on the ignition switch “ON”.

Is the MAP voltage value displayed on the Tech 2 below
the specified value?

1 V

Go to

Step 5

Go to

Step 6

Is the MAP voltage value displayed on the Tech 2 below
the specified value?

1 V

Refer to

Chart P0107

Refer to

Diagnostic

Aids and

Symptom

Diagnosis

Connect the relay and solenoid checker
(5-8840-0386-0) to the battery voltage, then check the
sensor grounding circuit.

Does the checker lamp come on?

—

Go to

Step 7

Go to

Step 8

A voltage short circuit occurs in the MAP signal circuit
or this circuit is shorted with the 5V power circuit.
Repair the harness or Replace the ECM (Refer to the
Data Programming in Case of ECM change).

Is the action complete?

—

Verify repair

—

Replace the MAP sensor hose or the MAP sensor.

Is the action complete?

—

Verify repair

—

Repair the harness for open ground circuit.

Is the action complete?

—

Verify repair

—

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