For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptors

DTC P0341: Camshaft Position (CMP) Sensor Performance
DTC P0342: Camshaft Position (CMP) Sensor Circuit

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Ignition 1 Voltage | P0562, P0443, P0342, P1403 | P0342 | -- | P0341
CMP Sensor Signal | P0342 | P0342 | P0342 | P0341
Low Reference | -- | P0342 | -- | P0341

### Circuit/System Description

The camshaft position (CMP) sensor correlates the crankshaft to camshaft position so that the engine control module (ECM) can determine which cylinder is ready to be fueled by an injector. As the camshaft rotates, the reluctor wheel interrupts a magnetic field produced by a magnet within the sensor and sends a signal to the ECM through the signal circuit. The CMP sensor circuits are directly connected to the ECM. The CMP sensor also determines which cylinder is misfiring. The CMP sensor circuits consist of the following:

• | An ignition 1 voltage

• | A low reference

• | A CMP signal

### Conditions for Running the DTC

• | The engine is running.

• | The DTCs run continuously when the above condition is met.

### Conditions for Setting the DTC

#### P0341

The ECM detects an incorrect CMP signal for 5 seconds.

#### P0342

The ECM detects no CMP signal for 32 top dead center (TDC) cylinder 1 events.

### Action Taken When the DTC Sets

DTC P0341 is a Type A DTC. DTC P0342 is a Type B DTC.

### Conditions for Clearing the DTC

DTC P0341 is a Type A DTC. DTC P0342 is a Type B DTC.

### Diagnostic Aids

The following conditions can also set the DTC:

• | Physical damage to the CMP sensor or the reluctor wheel.

• | Excessive play or looseness of the CMP sensor or the reluctor wheel.

• | Improper installation of the CMP sensor or the reluctor wheel.

• | Foreign material passing between the CMP sensor and the reluctor wheel

• | Excessive air gap between the CMP sensor and the reluctor wheel

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Electronic Ignition (EI) System Description

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

1. Engine running, observe the DTC information with a scan tool. DTCs P0341 and P0342 should not set.
2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the CMP sensor.
2. Ignition ON, verify that a test lamp illuminates between the ignition 1 voltage circuit terminal 1 and ground.

⇒ | If the test lamp does not illuminate, test the ignition 1 voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition 1 voltage circuit fuse is open, test all components connected to the ignition 1 voltage circuit and replace as necessary.

3. Connect a test lamp between the ground circuit terminal 2 and the ignition 1 voltage circuit terminal 1. Verify the test lamp illuminates.

⇒ | If the test lamp does not illuminate, repair the open/high resistance on the ground circuit.

4. Test for 4.8-5.2 volts between the signal circuit terminal 3 and the ground circuit terminal 2.

⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.

⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.

5. If all circuits test normal, test or replace the CMP sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Camshaft Position Sensor Replacement

• | Control Module References for engine control module replacement, setup, and programming