Conditions for Setting the DTC

WARNING: This page is about a different car, the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

The system constantly monitors the voltage on the switch signal circuit.
If the system detects a voltage level outside the possible range produced when no buttons are depressed, (approx.-0.5 to 1.0 volts), the DTC is logged.