Conditions for Setting the DTC

WARNING: This page is about a different car, the 2006 Buick LaCrosse and 2006 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.

The BCM detects a short to battery positive voltage, short to ground, poor connection or an open in the park lamp relay control circuit when it is trying to energize the PK LP relay.
The BCM detects a short to ground in the switched park lamp voltage supply circuit.
The condition above must be present for more than 0.3 seconds.