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

Valve Controls and Brake Switch


Object Number: 1234512  Size: FS
Master Electrical Component List
Transmission Component and System Description
Switch Inputs
OBD II Symbol Description Notice
BRAKE, HTR/AC, and HVAC 1 Fuses
Ignition Switch - START, RUN, and ACC/RUN/START Bus Bars
BRAKE, HTR/AC, and HVAC 1 Fuses
IGN 0, TBC IGN 0,TBC ACCY, SEO ACCY, RR WPR, and WS WPR Fuses
4.8, 5.3, 6.0, and 8.1L - 2 of 2
4.3L - 2 of 2
8600 GVW or Less - 2 of 2
Figure 2:

Switch Inputs


Object Number: 1234524  Size: FS
Master Electrical Component List
Transmission Component and System Description
Tow/Haul and PNP Switches
Valve Controls and Brake Switch
OBD II Symbol Description Notice
Figure 3:

Tow/Haul and PNP Switches


Object Number: 1234655  Size: FS
Master Electrical Component List
Transmission Component and System Description
Vehicle Speed and 4WD Signal
Switch Inputs
OBD II Symbol Description Notice
SP205 - 2 of 2
G203 - 1 of 3
G203 - 1 of 3
G103 - Gas
Figure 4:

Vehicle Speed and 4WD Signal


Object Number: 1234660  Size: FS
Master Electrical Component List
Transmission Component and System Description
Auxiliary Pump Controls - Hybrid Only
Tow/Haul and PNP Switches
OBD II Symbol Description Notice
Figure 5:

Auxiliary Pump Controls - Hybrid Only


Object Number: 1375212  Size: FS
Master Electrical Component List
Transmission Component and System Description
Vehicle Speed and 4WD Signal
OBD II Symbol Description Notice
Continuous Mode Bus Bar (HP2)
Continuous Mode Bus Bar (HP2)
Continuous Mode Bus Bar (HP2)
G104, G106, and G107
G104, G106, and G107