Conditions for Setting the DTC
WARNING: This page is about a different car, the 2007 Pontiac G5 Pursuit, 2007 Pontiac G5, and 2007 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
The ECM detects 25 out of the last 35 cam revolutions occur with 2 cam sensor pulses outside the CKP window.