Conditions For Setting DTC
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2002 Pontiac Grand Prix, 2002 Pontiac Bonneville, 2002 Chevrolet Monte Carlo, 2002 Chevrolet Impala, and 2002 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.
Ratio of 18X reference pulses to CAM signal pulses received by PCM equals 36:1 and the ratio of 18X reference pulses to 3X reference pulses received by PCM does not equal 6:1 for up to 30 seconds.