Circuit/System Verification
WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition ON, observe the scan tool Headlamp Switch parameter while turning the headlamp switch ON and OFF. The reading should toggle between Active and Inactive.
- If the reading does not change between the commanded states, refer to Headlamp Switch Malfunction .
- Observe the scan tool Flash to Pass Switch parameter while applying and releasing the flash to pass switch. The reading should toggle between Active and Inactive.
- If the reading does not change between the commanded states, refer to Headlamp Dimmer Switch Malfunction .
- Observe the scan tool High Beam Select Switch parameter while applying and releasing the high beam select switch. The reading should toggle between Active and Inactive.
- If the reading does not change between the commanded states, refer to Headlamp Dimmer Switch Malfunction .
- Observe the scan tool Auto Hdlp. Disable Sw. parameter while applying and releasing the automatic lamp control disable switch. The reading should toggle between Active and Inactive.
- If the reading does not change between the commanded states, refer to Headlamp Switch Malfunction .
- Command the Low Beams ON and OFF with a scan tool. The low beam headlamps should turn ON and OFF when commanded.
- If the low beam headlamps do not turn ON and OFF when commanded, refer to Headlamps Malfunction - Low Beam .
- Command the High Beams ON and OFF with a scan tool. The low beam headlamps should turn ON and OFF when commanded.
- If the high beam headlamps do not turn ON and OFF when commanded, refer to Headlamps Malfunction - High Beam .