Conditions for Setting the DTC

WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.

Ignition ON engine OFF, the ECM/PCM detects a PWM signal that is greater than 65 percent for 5 seconds.
Engine running, the ECM/PCM detects a PWM signal that is less than 5 percent for 15 seconds.