Possible causes

– Faulty crankshaft position sensor
– Crankshaft position sensor harness is open or shorted
– Crankshaft position sensor circuit poor electrical connection

When is the code detected?

The Powertrain Control Module (PCM) determines no signal from the Crankshaft Position (CKP) sensor for less than 3 seconds.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)
– Possible lack/loss of Power
– Engine may stall while driving

P0335 GMC Description

The Crankshaft Position Sensor (CKP) works in conjunction with a 24X reluctor wheel mounted on the rear of the crankshaft. The CKP sensor has a B+ power supply, a ground, and a signal circuit. As the crankshaft rotates, the reluctor wheel teeth interrupt a magnetic field produced by a magnet within the sensor. The sensor’s internal circuitry detects this and produces a signal which the Powertrain Control Module (PCM) reads. The PCM uses this signal to accurately measure crankshaft velocity which is a variable used in order to detect misfire, spark and, fueling.

GMC Technical Service Bulletins for P0335 code