Opel Frontera UBS. Manual - part 1209

6E–202

ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P0342 CMP Sensor Circuit Low

D06RW032

Circuit Description

The CMP signal produced by the camshaft position
(CMP) sensor pulses when the engine is running and
crankshaft position (CKP) sync pulses are also being
received.  The hall type CMP sensor and the CKP sensor
share 5 V and ground connections at the powertrain
control module (PCM).  The third wire at the sensor is a
signal circuit to the PCM.  The PCM uses the CMP signal
pulses to initiate sequential fuel injection.  The PCM
constantly monitors the number of pulses on the CMP
signal circuit and compares the number of CMP pulses to
the number of 58X reference pulses received.  If the PCM
does not receive pulses on the CMP reference circuit,
DTC P0342 will set and the PCM will initiate injector
sequence without the CMP signal with a one in six chance
that injector sequence is correct.  The engine will continue
to start and run normally, although the misfire diagnostic
will be affected if a misfiring condition occurs.

Conditions for Setting the DTC

D

The engine is running.

D

The CMP sensor signal is not received by the PCM
once every 6 cylinders.

D

The above condition occurs for 10 seconds.

Action Taken When the DTC Sets

D

The PCM will illuminate the malfunction indicator lamp
(MIL) after the second consecutive trip in which the
fault is detected.

D

The PCM will initiate injector sequence without the
CMP signal with a one in six chance that the injector
sequence is correct.

D

The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.

6E–203

ENGINE DRIVEABILITY AND EMISSIONS

Conditions for Clearing the MIL/DTC

D

DTC P0342 can be cleared by using Tech 2 “Clear Info”
function or by disconnecting the PCM 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:

D

Poor connection – Inspect the PCM harness and
connectors for 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, disconnect
the PCM, turn the ignition on and observe a voltmeter

connected to the CMP signal circuit at the PCM
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 PCM.  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.

DTC P0342 – CMP Sensor Circuit Low

 

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.”
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records

conditions as noted.

4. Using Tech 2, monitor “Specific DTC” information

for DTC P0342 until the DTC P0342 test runs.

5. Note test result.

Does Tech 2 indicate DTC P0342 failed this ignition?

—

Go to 

Step 3

Refer to

Diagnostic

Aids

3

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

4

1. Ignition “OFF,” disconnect the PCM 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

5

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

Was a problem found?

—

Verify repair 

Go to 

Step 6

6

1. Check the following circuits between the PCM and

the CMP sensor:

D

The sensor feed circuit.  Open or short to
ground?

D

The sensor ground circuit.  Open or short to
voltage?

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

Was a problem found?

—

Verify repair

—

6E–204

ENGINE DRIVEABILITY AND EMISSIONS

DTC P0342 – CMP Sensor Circuit Low

  (Cont'd)

Step

No

Yes

Value(s)

Action

7

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

8

1. Turn the ignition “OFF.”
2. Disconnect the PCM and connect a DVM to monitor

voltage on the camshaft position signal circuit at the
PCM connector.

3. Ignition “ON.”
4. Monitor the voltage display on the DVM while

repeatedly touching the CMP sensor signal circuit
at the CMP sensor connector with a test light to
ground.

Does the DVM voltage display switch between 0 and
approximately 5 volts when the test light is touched to
the CMP sensor signal circuit?

—

Go to 

Step 12

Go to 

Step 9

9

1. Ignition “OFF.”
2. Leave the PCM disconnected.
3. Ignition “ON.”
4. Probe the camshaft position signal circuit at the

PCM connector with a test light to B+.

5. If the test light is “ON,” locate and repair the short to

ground in the camshaft position input signal circuit.

Was either circuit shorted to ground?

—

Verify repair

Go to 

Step 10

10

1. Ignition “OFF.”
2. Leave the PCM disconnected.
3. Ignition “ON.”
4. Probe the camshaft position signal circuit with a test

light to ground.

5. If the test light is “ON,” locate and repair the short to

voltage in the camshaft position input signal circuit.

Was the test light “ON”?

—

Verify repair

Go to 

Step 11

11

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

sensor disconnected).

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

D

The CMP sensor signal circuit for an open.

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

Was a problem found?

—

Verify repair

—

12

1. Ignition “ON.”
2. Remove the CMP sensor from the engine front

cover (leave the sensor wiring connected).

3. 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 14

Go to 

Step 13

13

Replace the camshaft position sensor.

Is the action complete?

—

Verify repair

—

6E–205

ENGINE DRIVEABILITY AND EMISSIONS

DTC P0342 – CMP Sensor Circuit Low

  (Cont'd)

Step

No

Yes

Value(s)

Action

14

1. Reinstall the CMP sensor to the engine front cover.
2. Observe the DVM connected to monitor voltage on

the camshaft position signal circuit while cranking
the engine.

Does the voltage toggle between the specified values?

4-0 V

Go to 

Step 15

Go to 

Step 16

15

Replace the PCM.

NOTE: The replacement PCM must be programmed.
Refer to 

UBS 98model year Immobilizer Workshop

Manual.

Is the action complete?

—

Verify repair

—

16

Replace faulty or missing camshaft magnet.

Is the action complete?

—

Verify repair

—