Diagnostic Aids
WARNING: This page is about a different car, the 2002 Oldsmobile Bravada, 2002 GMC Envoy XL, 2002 GMC Envoy, and 2002 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
- The scan tool camshaft phase control function increments the cam phaser in 10 percent increments. Each increment equates to 2.5 degrees of cam phasing. A cam phase angle of 15 degrees is achieved by commanding the camshaft actuation system with the scan tool to 60 percent.
- Inspect any engine mechanical work that has been performed recently. Verify that the engine timing has not been altered.
- If this DTC is set along with any crankshaft position (CKP) or camshaft position (CMP) sensor DTCs, then both the CKP and CMP sensor DTCs should be diagnosed prior to performing this diagnostic. The PCM uses both inputs to determine the actual camshaft position.
- Check for the following items:
- A loose CMP sensor causing a variance in the sensor signal.
- A loose CKP sensor causing a variance in the sensor signal.
- Debris or contamination interfering with the camshaft position actuator solenoid valve assembly.
- Engine oil has a major impact upon the camshaft actuation system's responsiveness. Oil temperature, pressure, viscosity, and quality can slow and/or inhibit the actuator systems ability to reach a desired phase angle.
- An intermittent may be caused by any of the following conditions:
- A poor connection
- Rubbed through wire insulation
- A broken wire inside the insulation
- Thoroughly check any circuitry that is suspected of causing the intermittent complaint. Repair the circuits as necessary.