Circuit/System Verification

WARNING: This page is about a different car, the 2009 GMC Canyon and 2009 Chevrolet Colorado. However, it is still accessible from the selected car via links, so may be relevant.

Ignition ON, observe the scan tool Dimming Potentiometer parameter while operating the dimmer switch from high to low. The voltage reading should change from high to low as the switch is rotated.

If the reading does not change, refer to Dimmer Switch Malfunction below.
If the scan tool dimmer control operates normal, refer to Interior Backlighting Malfunction below.