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 Descriptor

DTC P0340: Intake Camshaft Position (CMP) Sensor Circuit
DTC P0365: Exhaust Camshaft Position (CMP) Sensor Circuit

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Intake CMP Sensor 5-Volt Reference Circuit | P0452, P0532, P0641 | P0340, P0365 | P0641, P0533 | --
Intake CMP Sensor Signal Circuit | P0340 | P0340 | P0340 | P0341
Intake CMP Sensor Low Reference Circuit | -- | P0340 | P0340 | --
Exhaust CMP Sensor 5-Volt Reference Circuit | P0452, P0532, P0641 | P0365 | P0641, P0533 | --
Exhaust CMP Sensor Signal Circuit | P0365 | P0365 | P0365 | P0366
Exhaust CMP Sensor Low Reference Circuit | -- | P0365 | P0365 | --

### Circuit/System Description

Each camshaft is equipped with a camshaft position (CMP) sensor that the engine control module (ECM) monitors. The CMP sensor is a hall effect switch that works in conjunction with a 4X reluctor wheel. The reluctor wheels are mounted to the camshaft position actuators that are mounted to the end of the camshafts. The ECM uses the CMP sensor signals in order to determine the position of the camshafts. The ECM supplies 5 volts to the CMP sensors on the 5-volt reference circuits, and supplies a ground on the low reference circuits. The CMP sensors provide a signal to the ECM on the signal circuits.

### Conditions for Running the DTC

• | DTC P0101, P0102, P0103, P0335, P0336, P0641, or P0651 is not set.

• | The engine is cranking or running.

• | The mass air flow (MAF) is greater than 3 grams per second.

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

### Conditions for Setting the DTC

• | The ECM detects that the starter is commanded ON, and the engine has been cranking for greater than 2 seconds, without a CMP sensor pulse.

• | The ECM detects that the engine has started, but did not receive a CMP sensor pulse during the first engine revolution.

• | The ECM detects that the engine is running, but does not receive a CMP sensor pulse for 80 out of 100 engine cycles.

### Action Taken When the DTC Sets

• | DTCs P0340 and P0365 are Type B DTCs.

• | The CMP actuator is commanded to the Park position.

### Conditions for Clearing the DTC

DTCs P0340 and P0365 are Type B DTCs.

### Diagnostic Aids

With a DTC set, the engine may crank for an extended period of time during start-up.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Camshaft Actuator 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. Ignition ON, observe the DTC information with a scan tool. DTC P0641 should not be set.

⇒ | If DTC P0641 is set, refer to DTC P0641, P0651, P0697, or P06A3.

2. Engine idling, observe the scan tool Intake and Exhaust CMP Active Counter parameters. Both parameters should be incrementing.
3. Engine idling, observe the DTC information with a scan tool. DTC P0340 or P0365 should not set.
4. 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. Engine idling, move the related harnesses/connectors of the appropriate CMP sensor while monitoring the scan tool CMP Variance parameter. The CMP variance parameter should not change when moving the harness/connectors.

⇒ | If the above condition exists, repair the harness/connectors as necessary.

2. Ignition OFF, inspect the appropriate CMP sensor for correct installation.

⇒ | If the CMP sensor is loose, inspect the sensor and the O-ring for damage, and replace as necessary.

3. Ignition OFF, disconnect the harness connector at the appropriate CMP sensor.
4. Ignition OFF for 1 minute, test for less than 5 Ω 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 tests normal, replace the ECM.

5. Ignition ON, test for 4.8-5.2 V between the 5-volt reference circuit terminal 1 and ground.

⇒ | If less than the specified range, test the 5-volt reference 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 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.

6. Test for 4.8-5.2 V between the signal circuit terminal 3 and ground.

⇒ | 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.

7. Ignition OFF, connect a 3 A fused jumper wire to the CMP signal circuit terminal 3.
8. Ignition ON, momentarily touch the end of the fused jumper wire to ground while monitoring the scan tool CMP active counter. The CMP active counter should increment.

⇒ | If the CMP active counter does not increment, replace the ECM.

9. If all circuits 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