P0338

DTC P0338 Crankshaft Position Sensor Circuit - High Input:

Crankshaft Position Sensor Circuit:

CIRCUIT DESCRIPTION
The Crankshaft Position (CKP) sensor sends a reference (0 volt/5 volt, "OFF"/"ON") signal to the Vehicle Control Module-A (VCM-A) to indicate crankshaft position and RPM so that the VCM-A can determine when to pulse the ignition coil and control ignition timing. This diagnostic will detect a high duty cycle from the crankshaft sensor. DTC P0338 is a type "D" DTC.

DTC P0338 WILL SET WHEN
^ Engine speed is less than 2000 RPM. Crank sensor duty cycle is greater than 50% (or the ratio High Ref/Low Ref is greater than 5.6).

ACTION TAKEN (VCM-A WILL DEFAULT TO)
The VCM-A will not turn "ON" the Malfunction Indicator Lamp (MIL) (Service Engine Soon).

DTC P0338 WILL CLEAR WHEN
The VCM-A will turn the MIL "OFF" after three consecutive trips without a fault condition present. A history DTC will be cleared if no fault conditions have been detected for forty warm-up cycles [coolant temperature has risen 22°C (40°F) from start-up coolant temperature and engine coolant temperature exceeds 71°C (160°F) that same ignition cycle] or the Tech 1 clearing feature has been used.

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This step determines if DTC P0338 is the result of a hard failure or an intermittent condition.
2. Checks for crankshaft sensor low duty cycle.
3. Determines if voltage is available to the CKP through the VCM-A.
4. 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-A connections or VCM-A is faulty.
5. This test checks the crankshaft position sensor, the signal circuit and the VCM-A.

DIAGNOSTIC AIDS
An "Intermittent" problem may be caused by a poor connection, rubbed through wire insulation, or a wire that is broken inside the insulation.

Any circuitry, that is suspected as causing the intermittent complaint, should be thoroughly checked for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wiring connections or physical damage to the wiring harness.

Refer to Intermittents. - Intermittent Malfunctions