Conditions for Setting the DTC

WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

The PCM detects the heater control circuit voltage is less than a predetermined range when the circuit is commanded OFF.
The PCM detects the heater control circuit voltage is more than a predetermined range when the circuit is commanded ON.
The condition exists for more than 1 second.