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

Valve Controls and Brake Switch


Object Number: 1251070  Size: FS
Master Electrical Component List
Electronic Component Description
Switch Inputs
Engine Controls Schematic Icons
Ignition Switch - START, and RUN Bus Bars
BRAKE, HTR/AC, HVAC I, CRUISE, 4WD Fuses
Ignition Switch - ACC/RUN/START, ACC/RUN, and RUN/START Bus Bars
BRAKE, HTR/AC, HVAC I, CRUISE, 4WD Fuses
IGN 0, TBC IGN 0, TBC ACCY, SEO ACCY, W/S WPR, RR WPR Fuses
Stop Lamp Switch and Traction Control Switch
Figure 2:

Switch Inputs


Object Number: 1234524  Size: FS
Master Electrical Component List
Electronic Component Description
Tow/Haul Switch and PNP Switch Inputs
Valve Controls and Brake Switch
Engine Controls Schematic Icons
Figure 3:

Tow/Haul Switch and PNP Switch Inputs


Object Number: 1251074  Size: FS
Master Electrical Component List
Electronic Component Description
Vehicle Speed Signal and 4WD Low Signal
Switch Inputs
Engine Controls Schematic Icons
SP205 - 2 of 2
G203 - 3 of 3
G203 - 1 of 3
G203 - 1 of 3
G102, G103
Figure 4:

Vehicle Speed Signal and 4WD Low Signal


Object Number: 1251077  Size: FS
Master Electrical Component List
Electronic Component Description
Tow/Haul Switch and PNP Switch Inputs
Engine Controls Schematic Icons