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: Camshaft Position (CMP) Sensor Performance
DTC P0340: Camshaft Position (CMP) Sensor Circuit

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Ignition 1 Voltage | P0562, P0340 | P0340 | -- | P0016
CMP Sensor Signal | P0340 | P0340 | P0340 | P0016
Low Reference | -- | P0340 | -- | P0016

### 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

#### P0016

The ECM detects an incorrect CMP signal for 5 seconds.

#### P0340

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

### Action Taken When the DTC Sets

DTC P0340 is a Type A DTC. DTC P0016 is a Type B DTC.

### Conditions for Clearing the DTC

DTC P0340 is a Type A DTC. DTC P0016 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

• | Engine Control Module Connector End Views

• | Engine Controls 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

• | 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 and P0340 should not set.
2. If the vehicle passes the Circuit/System Verification Test, then 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 Data List.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector of the CMP sensor.
2. Ignition ON, load test for battery voltage between the ignition 1 voltage circuit of the CMP sensor and ground.

⇒ | If less than B+, repair the ignition 1 voltage circuit of the CMP sensor for a short to ground or an open/high resistance.

3. Connect a test lamp between the ground circuit and the ignition 1 voltage circuit of the CMP sensor.

⇒ | If the test lamp does not illuminate, test for an open/high resistance on the ground circuit. If circuit/connections test normal, replace the ECM.

4. Ignition OFF, connect a DMM between the signal circuit and the low reference circuit of the CMP sensor.
5. Ignition ON, verify that 4.8-5.2 volts is available on the signal circuit and the low reference circuit of the CMP sensor.

⇒ | If less than 4.8 volts, test the signal circuit for a short to ground or an open/high resistance. If the circuits/connections test normal, replace the ECM.

⇒ | If more than 5.2 volts, test the signal circuit for a short to voltage. If the circuits/connections test normal, replace the ECM.

6. 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 engine control module replacement, setup, and programming