Diagnostic Aids

WARNING: This page is about a different car, the 2003 Oldsmobile Bravada, 2003 GMC Envoy XL, 2003 GMC Envoy, and 2003 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

Crankshaft Position (CKP) signal is not needed to start and run.
Many situations may lead to an intermittent condition. Perform each inspection or test as directed.

NOTE: Remove any debris from connector surfaces before servicing a component. Ensure gaskets are installed correctly. Gaskets prevent contaminate intrusion.

Inspect PCM and engine grounds for clean and secure connections.
For intermittent conditions, see INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 4.2L BRAVADA, ENVOY, ENVOY XL, TRAILBLAZER & TRAILBLAZER EXT article.