Content .. 616 617 618 619 ..

Isuzu Trooper (1998-2002 year). Manual - part 618

6E–120

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

DTC P0341 —CMP Sensor Out of Synchro

Step

Action

Value(s)

Yes

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

—

Go to

Step 2

Go to

OBD

System

Check

1. Ignition “ON.”
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 P0341

until the DTC P0341 test runs.

5. Note the test result.

Does the Tech 2 indicate DTC P0341 failed this
ignition?

—

Go to

Step 3

Refer to

Diagnostic

Aids

1. Disconnect the CMP sensor.
2. Measure the voltage between the sensor feed

circuit and the sensor ground circuit at the CMP
sensor harness connector.

Does the voltage measure near the specified value?

4-6 V

Go to

Step 4

Go to

Step 5

Measure the voltage between the CMP sensor signal
circuit and the sensor ground circuit at the CMP sensor
harness connector.

Does the voltage measure near the specified value?

4-6 V

Go to

Step 11

Go to

Step 8

If the voltage measured in step 3 was less than 4-6
volts, proceed directly to step 6 without completing this
step.
If the voltage in step 3 was greater than 4-6 V, repair the
short to voltage in the CMP feed circuit.

Is the action complete?

—

Verify repair

—

1. Check for poor connections at the camshaft

position sensor.

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

Was a problem found?

—

Verify repair

Go to

Step 7

1. Ignition “OFF,” disconnect the ECM and the CMP

sensor.

2. Check the following circuits for an open between the

ignition control module and the CMP sensor:

The sensor feed circuit.

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

Was a problem found?

—

Verify repair

Go to

Step 9

1. Ignition “OFF,” disconnect the ECM (leave the CMP

sensor disconnected).

2. Ignition “ON,” check the following circuits:

The CMP sensor signal circuit for an open or a
short to voltage.

The CMP sensor input signal circuit for a short
to ground.

3. If a problem is found, repair it as necessary.

Was a problem found?

—

Verify repair

Go to

Step 9

Check for a short or open in the sensor ground circuit.

Was a problem found?

—

Verify repair

Go to

Step 10

6E–121

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

DTC P0341 —CMP Sensor Out of Synchro

(Cont'd)

Step

Yes

Value(s)

Action

1. Check for poor connections at the ECM.
2. If a problem is found, repair it as necessary.

Was a problem found?

—

Verify repair

Go to

Step 11

Backprobe the ECM connector with a DVM to monitor
voltage on the camshaft position input signal circuit
while cranking the engine with the sensor connected.
(Use rubber band, tape, or an assistant to keep the
DVM lead in contact with the sensor terminal during this
test.)

Does the voltage toggle between the specified values?

4-0 V

Go to

Step 15

Go to

Step 12

1. Remove the CMP sensor from the engine front

cover (leave the sensor wiring connected).

2. Place a magnet on the CMP sensor.
(If you use a magnet that is too small to cover the face
of the sensor, test on every part of the sensor face
because only a small area will respond to this test.)

Does the DVM display a voltage near the specified
value?

0 V

Go to

Step 13

Go to

Step 14

Replace the faulty or missing camshaft position sensor
magnet.

Is the action complete?

—

Verify repair

—

Replace the camshaft position sensor.

Is the action complete?

—

Verify repair

—

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

Is the action complete?

—

Verify repair

—

6E–122

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P0342 (Flash DTC 41)

CMP (Cam Position) Sensor No Signal

060RW133

Circuit Description

The CMP signal produced by the camshaft position
(CMP) sensor pulses when the engine is running and
crankshaft position (CKP) synchro pulses are also being
received. The hall type CMP sensor and the CKP sensor
share 5 V and ground connections at the Engine Control
Module ECM. The third wire at the sensor is a signal
circuit to the ECM. The ECM uses the CMP signal pulses
to initiate sequential fuel injection. If the ECM does not
receive pulses on the CMP reference circuit, DTC P0342
will set.

Action Taken When the DTC Sets

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 P0342 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the ECM battery
feed.

Diagnostic Aids

An intermittent may be caused by a poor connection,
rubbed-through wire insulation or a wire broken inside the
insulation. Check for:

Poor connection – Inspect the ECM harness and
connectors for 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, disconnect
the ECM, turn the ignition on and observe a voltmeter
connected to the CMP signal circuit at the ECM
harness connector while moving connectors and
wiring harnesses related to the ICM and the CMP
sensor. A change in voltage will indicate the location
of the fault.

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. Ensures that the fault is present.

14.Determines whether the fault is being caused by a

missing camshaft magnet or a faulty ECM. The
voltage measured in this step should read around 4
volts, toggling to near 0 volts when the CMP sensor
interfaces with the camshaft magnet.

6E–123

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

DTC P0342 —CMP Sensor No Signal

Step

Action

Value(s)

Yes

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

—

Go to

Step 2

Go to

OBD

System

Check

1. Ignition “ON.”
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 “Specific DTC” information

for DTC P0342 until the DTC P0342 test runs.

5. Note test result.

Does the Tech 2 indicate DTC P0342 failed this
ignition?

—

Go to

Step 3

Refer to

Diagnostic

Aids

1. Ignition “ON.”
2. Disconnect the CMP sensor.
3. Measure the voltage between the sensor feed

circuit and the sensor ground circuit at the CMP
sensor harness connector.

Does the voltage measure near the specified value?

4-6 V

Go to

Step 7

Go to

Step 4

1. Ignition “OFF,” disconnect the ECM and the CMP

sensor.

2. Check for poor connections at the camshaft

position sensor.

3. If a problem is found, repair it as necessary.

Was a problem found?

—

Verify repair

Go to

Step 5

1. Check for poor connections at the ECM.
2. If a problem is found, repair it as necessary.

Was a problem found?

—

Verify repair

Go to

Step 6

1. Check the following circuits between the ECM and

the CMP sensor:

The sensor feed circuit. Open or short to
ground?

The sensor ground circuit. Open or short to
voltage?

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

Was a problem found?

—

Verify repair

—

1. Ignition “ON,” engine “OFF.”
2. Measure the voltage between the CMP sensor

signal circuit and the sensor ground circuit at the
CMP sensor harness connector.

Does the voltage measure near the specified value?

4-6 V

Go to

Step 8

Go to

Step 9

Content .. 616 617 618 619 ..