P0338

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The Crankshaft Position (CKP) sensor sends a reference signal to the Vehicle Control Module (VCM). The CKP reference signal is used to determine crankshaft position and engine RPM. This information is used by the VCM in order to determine when to pulse the ignition coil and to control the ignition timing. This diagnostic will detect a low duty cycle from the crankshaft sensor.

CONDITIONS FOR SETTING THE DTC

The following conditions will set the DTC:

^ The change in engine speed is greater than 1000 RPM

^ The MAF is at least 5 g/s

ACTION TAKEN WHEN THE DTC SETS

The VCM will turn ON the MIL after 2 consecutive driving cycles with the fault active.

CONDITIONS FOR CLEARING THE MIL/DTC

^ A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles (coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant temperature exceeds 70°C (160°F) during the same ignition cycle.

^ Use the scan tool Clear Information function.

^ Disconnect the VCM battery feed for 30 seconds.

DIAGNOSTIC AIDS

A poor connection, a rubbed through wire insulation, or a wire that is broken inside the insulation may cause an intermittent problem.

Thoroughly check any circuitry, that is suspected of causing the intermittent complaint for the following conditions:

^ Backed out terminals

^ Improper mating

^ Broken locks

^ Improperly formed or damaged terminals

^ Poor terminal to wiring connections

^ Physical damage to the wiring harness

Inspect the face of the CKP sensor for metal shavings. This could result in an intermittent DTC P0339.

Refer to Symptoms. Testing and Inspection

TEST DESCRIPTION

The numbers below refer to the step numbers on the diagnostic table.

3. This step determines it DTC P0338 is the result of a hard failure or an intermittent condition.

5. Determines if voltage is available to the CKP through the VCM.

6. If the feed circuit is shorted to ground, the test light will be ON. This step determines if the circuit is open or shorted to ground. If the circuit is OK, then the VCM connections or VCM is faulty.

7. This test checks the crank sensor, crank sensor signal circuit and the VCM.