GM Service Manual Online
For 1990-2009 cars only
Figure 1:

Ambient Light Sensor, Headlamp Controls and Switches


Object Number: 1907420  Size: FS
Master Electrical Component List
Exterior Lighting Systems Description and Operation
Control Module References
Headlamps - TT5
Figure 2:

Headlamps - TT5


Object Number: 1907425  Size: FS
Master Electrical Component List
Exterior Lighting Systems Description and Operation
Control Module References
Ambient Light Sensor, Headlamp Controls and Switches