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.

This code will only set at idle.
An improperly torqued harmonic balancer or misbuilt engine.
The PCM will disable the ability to command the variable cam phaser on the scan tool. This will prevent engine damage from excessive valve overlap.