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 P0016 5A: Camshaft Position (CMP) Sensor Circuit Plausibility Failure
DTC P0340 28: Camshaft Position (CMP) Sensor Circuit Incorrect Frequency
DTC P0340 29: Camshaft Position (CMP) Sensor Circuit Too Few Pulses
DTC P0341: Camshaft Position (CMP) Sensor Circuit

### 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.

### Conditions for Running the DTC

#### P0016

• | DTCs P0335 and P0336 are not set.

• | The engine is running.

• | The engine speed is greater than 50 RPM.

• | The DTCs run continuously once the above conditions are met.

#### P0340 and P0341

• | DTC P0016 is not set.

• | The engine is running.

• | The engine speed is greater than 50 RPM.

• | The DTCs run continuously once the above conditions are met.

### Conditions for Setting the DTC

#### P0016

The ECM detects an incorrect CMP signal.

#### P0340

The ECM detects too few CMP pulses.

#### P0341

The ECM detects no CMP signal.

### Action Taken When the DTC Sets

DTCs P0016, P0340, and P0341 are Type B DTCs.

### Conditions for Clearing the DTC

DTCs P0016, P0340, and P0341 are Type B DTCs.

### 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

• | Engine Control Module Connector End Views

• | Engine Controls Connector End Views

#### 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

• | Scan Tool Data List

• | Scan Tool Data Definitions

• | Scan Tool Output Controls

### Circuit/System Verification

1. Start the engine, observe the DTC information with a scan tool. DTCs P0016, P0340, and P0341 should not set.
2. Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records List.

### Circuit/System Testing

1. Ignition OFF, and the MAIN fuse removed, disconnect the harness connector at the CMP sensor.
2. Test for less than 5 ohms of resistance between the low reference circuit terminal 2 and ground.

⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit/connections test normal, replace the ECM.

3. Install the MAIN fuse. Ignition ON, verify that a test lamp illuminates between the ignition 1 voltage circuit terminal 3 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.

4. Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal 1 and ground.

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

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

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

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Camshaft Position Sensor Replacement

• | Control Module References for ECM replacement, setup, and programming