P0340

Circuit Description

The diagnostic test checks for CAM reference pulses not received when 4X reference pulses are being received. This indicates a CAM sensor circuit failure and DTC P0340 is set.

Conditions for Running the DTC

^ DTC P0322 not set.
^ 4X reference pulses being received.
^ Engine speed 1600 RPM or less.

Conditions for Setting the DTC

A CAM reference pulse was not received for 5.3 seconds.

Action Taken When the DTC Sets

^ The PCM will illuminate the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
^ The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records.

Conditions for Clearing the MIL/DTC

^ The PCM will turn the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail.
^ A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail.
^ A History DTC will clear after forty consecutive warm-up cycles with no failures of any emission related diagnostic test.
^ Use a scan tool to clear DTCs.
^ Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

2. Check to see if DTC P1376 is set because a REF LO problem can cause other ignition problems.
3. Checking the resistance of the camshaft position sensor. The resistance should be 800 to 2100 ohms. If the resistance is greater, check for an open or if it is less, check for a short to ground or each other.
5. To ensure accurate voltage readings, connect the DMM J 39200 to the sensor before recording the Peak Min Max voltage. If the sensor is able to produce a voltage greater than 0.2 volt the sensor is OK A typical cam sensor should produce an average of 1 volt. Duplicate this test on a known good vehicle to get a comparison voltage if a marginal cam sensor is suspected.