P0337

Circuit Description
The 58X reference signal is produced by the Crankshaft Position (CKP) sensor. During one crankshaft revolution, 58 crankshaft pulses will be produced. The power-train control module (PCM)/engine control module (ECM) uses the 58X reference signal to calculate engine rpm and CKP. The PCM/ECM constantly monitors the number of pulses on the 58X reference circuit and compares them to the number of Camshaft Position (CMP) signal pulses being received. If the PCM/ECM receives and incorrect number of pulses on the 58X reference circuit, DTC P0336 will set.

Conditions for Setting the DTC
- No CMP sensor DTCs are set (P0341 and P0342).
- Engine cranking.

Action Taken When the DTC Sets
- The PCM/ECM will illuminate the Malfunction Indicator Lamp (MIL) after the second consecutive trip in which the fault is detected.
- The PCM/ECM will store conditions which were present when the DTC was set as Freeze Frame and in the Failure Records data.
- A history DTC is stored.

Conditions for Clearing the MIL/DTC
- The PCM/ECM will turn the MIL off on the third consecutive trip cycle during which the diagnostic has been run and the fault condition is no longer present.
- A history DTC P0336 will clear after 40 consecutive warm up cycles have occurred without a fault.
- DTC P0336 can be cleared by using the scan tool CLEAR INFO function or by disconnecting the PCM/ECM battery feed.

Steps 1 - 9:

Steps 10 - 11:

Diagnostic Aids
An intermittent may be caused by a poor connection, rubbed-through wire insulation or a wire broken inside the insulation. Check for:
- Poor connection - Inspect the PCM/ECM harness and connectors for improper mating, broken locks, improperly formed or damaged terminals, and poor terminal-to-wire connection.
- Damaged harness - Inspect the wiring harness for damage. If the harness appears to be OK, disconnect the PCM/ECM, turn the ignition ON and observe a voltmeter connected to the 58X reference circuit at the PCM/ECM harness connector while moving the connectors and the wiring harnesses related to the PCM/ECM. A change in voltage will indicate the location of the fault.

Reviewing the Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.