P0340

CIRCUIT DESCRIPTION
The Camshaft Position (CMP) sensor has a 12-volt reference circuit, a low reference circuit, and a signal circuit. The Powertrain Control Module (PCM) supplies 12 volts to the sensor. The PCM determines which pair of cylinders is at Top Dead Center (TDC) using the Crankshaft Position (CKP) sensor data. The 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.

CONDITIONS FOR RUNNING THE DTC
The engine is 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 (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
^ The PCM records the operating conditions at the time the diagnostic fails. 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 3 consecutive drive trips during which the diagnostic runs and passes.
^ A last test failed, or the current DTC, clears when the diagnostic runs and passes.
^ A History DTC clears after 40 consecutive warm-up cycles, if no other emission related diagnostic failures are reported.
^ Use a scan tool in order to clear the MIL diagnostic trouble code.
^ Interrupting the PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Powertrain Control Module (PCM) Description.

DIAGNOSTIC AIDS

NOTE: Refer to Connector Test Adapter Kit J 35616-A Notice in Service Precautions

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 below 120 RPM. Review Freeze Frame and 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.

If the problem is intermittent, refer to Intermittent Conditions. Intermittent Conditions

TEST DESCRIPTION

Steps 1-10:

Steps 11-22:

The number below refers to the step number on the diagnostic table.
2. If the engine does not start and run, check the 12-volt reference circuit to the CMP sensor for a short to ground.