GM Service Manual Online
For 1990-2009 cars only

Object Number: 896218  Size: MF

Circuit Description

The crankshaft position (CKP) sensor produces an AC voltage of different amplitude and frequency depending on the velocity of the crankshaft. The CKP sensor works in conjunction with a 58 tooth reluctor wheel on the crankshaft. Each tooth is spaced 6 degrees apart, with one span having a 12 degree space that is uncut. This uncut portion creates a pattern that enables the ECM to determine top dead center (TDC) for cylinder #1 and its mating cylinder, cylinder #4. The camshaft position (CMP) sensor is then used to determine when cylinder #1 is on its compression stroke. With both CKP sensor and CMP sensor inputs, the engine control module (ECM) can properly synchronize ignition timing, fuel delivery and spark knock control. DTC P0335 sets when the ECM does not receive a CKP sensor signal after a certain number of CMP sensor signal pulses have been received.

Conditions for Setting the DTC

DTC P0335 will set if the ECM does NOT receive a CKP sensor signal during which 8 valid CMP sensor signal pulses have been received when the CMP sensor signal pulses are greater than 25 RPM, the camshaft is spinning greater than 25 RPM/engine speed is greater than 50 RPM.

DTC P0335 diagnostic runs continuously with engine running or cranking.

DTC P0335 is a type B DTC.

Diagnostic Aids

The engine will NOT run if the ECM does not receive a CKP sensor signal regardless if a valid CMP sensor signal is received.

If the engine is running, this DTC is NOT active.

If the engine does not start, use the scan tool to monitor ENGINE SPEED while cranking over the engine. Wiggling the wires while checking for ENGINE SPEED may locate the area where an open, short to ground, or short to voltage in the wiring may exist.

Important: If this DTC is intermittent, allow the engine to reach normal operating temperature while checking for an engine stall condition. The CKP sensor may have an intermittent open or high resistance at higher temperatures.

CKP sensor resistance is 800-1,200 ohms.


Object Number: 898168  Size: FP