P0340

Circuit Description
The Camshaft Position (CMP) sensor signal, when combined with the CKP sensor signal, enables the PCM to determine exactly which cylinder is on a firing stroke. The PCM can then properly synchronize the ignition system, fuel injectors and knock control. The CMP sensor has a power, ground (reference low) and a signal circuit. The PCM supplies 12 Volts to the sensor. The power and reference low circuits are also connected to the CKP sensor.

Conditions for Running the DTC
Engine cranking or running.

Conditions for Setting the DTC
The PCM detects a problem with the CMP sensor signal.

Action Taken When the DTC Sets
^ The PCM illuminates the Malfunction Indicator Lamp on the second consecutive ignition cycle that the diagnostic runs and fails.
^ The PCM records the operating conditions at the time the diagnostic tails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure records.

Conditions for Clearing the MIL/DTC
^ The PCM turns the MIL Off after three consecutive drive trips that the diagnostic runs and does not fail.
^ A last test failed (current DTC) clears when the diagnostic runs and does not fail.
^ A History DTC clears after forty consecutive warm-up cycles, if this or any Other emission related diagnostic does not report any failures.
^ Use a scan tool in order to clear the MIL/DTC.
^ Interrupting the PCM battery voltage may or may not clear DTCs. This practice is not recommended.

Diagnostic Aids

Notice: Use the Connector Test Adapter Kit J 35616-A for any test that requires probing the following items:
^ The PCM harness connectors
^ The electrical center fuse/relay cavities
^ The component terminals
^ The component harness connector Using this kit will prevent damage caused by the improper probing of connector terminals.
Ensure that the engine grounds are clean and tight, including the main battery ground cable at the engine block.
If no trouble is found with the CMP sensor or the related circuitry, and DTC P0340 continues to set, the engine should be checked for incorrect cam timing.

CKP/CMP sensor DTCs may set if the key is turned to Start and the starter is inoperative. If P0335, P0340, and P0385 are set and no trouble is found, check for the following:
^ Is there a no-crank condition or an intermittent no-crank condition?
^ Was an attempt made to crank the engine with the shift lever not in P/N?
DTC P0340 may set if engine cranking speed is excessively slow (below 120 RPM). Review Freeze Frame/Failure Records to determine if the DTC set during cranking with an engine speed of less than 120 RPM. If this was the case, correct the cause of the slow cranking speed. The scan tool parameter CMP Sensor Data will not display an accurate RPM value below 120 RPM.

Test Description
Number(s) below refer to the step number(s) on the diagnostic table.
2. If the engine does not start and run, the power and ground circuits that serve the CMP sensor and the CKP sensor need to be checked. If the circuitry checks out OK, the PCM may be the problem, however this is an unlikely failure.