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.
- Whenever the PCM sees less than 15 resyncs in 256 seconds, the counter resets to zero. When a poor connection is present, the cam sensor active counter stops incrementing and the cam sensor resync counter starts to increment.
- Inspect the wiring harness for damage. If the harness appears to be okay, observe the CMP resync counter on scan tool while moving connectors and wiring harnesses related to the CMP sensor. If the CMP resync counter still does not count, then while still observing scan tool, operate any non-engine related electrical components on the vehicle. A change in display will indicate the location of the malfunction.
- A defective reluctor wheel or a cracked or damaged CMP sensor can result in an intermittent. Remove the camshaft position sensor and inspect for any damage. With the CMP sensor removed you can also inspect the reluctor wheel through the hole. Check the porosity and condition of the wheel. The edges must be square. Look for a nicked or damaged wheel.
- If the DTC is determined to be intermittent, see INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 4.2L BRAVADA, ENVOY, ENVOY XL, TRAILBLAZER & TRAILBLAZER EXT article.