Diagnostic Aids

WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

An intermittent CKP sensor signal may cause DTC P0336 to set. Wiggle the wiring harness with the engine running and observe the CKP Signal Missed parameter of the scan tool. If the parameter indicates anything other than 0, there is an intermittent condition. For an intermittent, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.
A short from the 12 volt reference circuit to the Low reference circuit internally in the Camshaft Position (CMP) or Crankshaft Position (CKP) sensor can cause all 3 DTCs P0336, P0340, P1345 to set.