P0340

DTC P0340 or P0341

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 provide an overview of each diagnostic category.

DTC Descriptors

DTC P0340
- Camshaft Position (CMP) Sensor Circuit

DTC P0341
- Camshaft Position (CMP) Sensor Performance

Diagnostic Fault Information






Typical Scan Tool Data






Circuit/System Description

The hall effect camshaft position (CMP) sensor produces 3 ON/OFF pulses for each revolution of the camshaft. The CMP output is pulse width encoded. The engine control module (ECM) uses the CMP and crankshaft position (CKP) output pulses to determine the engine speed and position. The CMP is connected directly to the ECM by the following circuits:

* The 5-volt reference circuit
* The low reference circuit
* The CMP sensor signal circuit

Conditions for Running the DTC

P0340
* The ignition is ON.
* The engine is turning faster than 50 RPM.
* DTCs P0340 and P0341 run continuously when the above conditions are met.
* DTCs P0335, P0336, P0642, or P0643 are not set.

P0341
* The ignition is ON.
* The engine is turning faster than 50 RPM.
* DTCs P0340 and P0341 run continuously when the above conditions are met.

Conditions for Setting the DTC

P0340

The ECM does not see a CMP sensor signal for more than 2 seconds.

P0341

The ECM determines that the CMP sensor signal is out of range for less than 2 seconds.

Action Taken When the DTC Sets

DTCs P0341 and P0342 are Type A DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0341 and P0342 are Type A DTCs.

Diagnostic Aids

If the CMP sensor signal is lost while running, the engine will operate normally. If the CMP sensor signal is not present on start-up, the engine will not start.

Circuit/System Verification

1. If DTCs P0642 or P0643 are set, diagnose those DTCs first.
2. Engine running, observe the DTC information with a scan tool. DTCs P0340 or P0341 should not set.
3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame Records data.

Circuit/System Testing

1. Ensure that the CMP sensor circuits are not routed too closely to the fuel injector wiring, after-market add-on electrical equipment, solenoids, relays, or motors.
2. With the key ON and the CMP sensor disconnected, measure the voltage between the 5-volt reference terminal 3 and a good ground and observe that the DMM measures 4.98-5.02 volts.

• If the DMM does not measure 4.98-5.02 volts, test the 5-volt reference for an open or high resistance. If the circuits test normal, replace the control module.

3. With the key ON and the CMP sensor disconnected, measure the voltage between the 5-volt reference circuit terminal 3 and the low reference circuit terminal 2 and observe that the DMM measures 4.98-5.02 volts.

• If the DMM does not measure 4.98-5.02 volts, test the low reference for an open or high resistance. If the circuits test normal, replace the control module.

4. With the key ON and the CMP sensor disconnected, connect a fused jumper wire to the signal circuit terminal 1 and momentarily and repeatedly probe the low reference circuit terminal 2, and observe if the Cam Signal Present and Engine RPM parameters change.

• If the cam signal and Engine RPM parameters do not change, test the signal circuit for an open, high resistance, a short to ground, a short to voltage. If the circuits test normal, replace the control module.

5. Remove the front engine cover and inspect the CMP sensor for physical damage, loose or improper installation, excessive air gap, foreign material passing between the sensor and the reluctor wheel, timing gear misalignment, or front engine cover damage.
6. Inspect the CMP reluctor wheel for physical damage, improper installation, or excessive endplay or looseness.
7. If no other condition is found, 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 Programming and Relearning
* Camshaft Reluctor Replacement Verification Tests