Diagnostic Aids

An intermittent problem can be caused by misrouted harness, rubbed-through wire insulation or broken wire inside insulation. Also, check for vacuum or PCV system leaks, incorrect PCV valve, engine oil dipstick not fully seated or engine oil filler cap loose or missing. Check for excessive build-up on throttle plate.

If problem is intermittent, see INTERMITTENT TROUBLE CODE DETERMINATION  under SELF-DIAGNOSTIC SYSTEM.

Fig 1: Identifying Components At Rear Of Engine

Courtesy of GENERAL MOTORS CORP.

Fig 2: Identifying Air Intake Components

Courtesy of GENERAL MOTORS CORP.

Fig 3: Locating Underhood Fuse Blocks

Courtesy of GENERAL MOTORS CORP.

Fig 4: Identifying Top & Bottom Underhood Fuse Blocks & Components

Courtesy of GENERAL MOTORS CORP.