Conditions for Setting the DTC

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.

During the ignition ON test, the PCM detects a PWM signal is out of range.
During the RUN test, the PCM detects a PWM signal less then 5 percent for more than 6 seconds.