GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2004 🢒 Savana 🢒 Body 🢒 Body Control System 🢒 Body Control System Schematics
Figure 1:

Power, Ground, Serial Data and Controlled/Monitored Subsystem References
Object Number: 1253825 Size: FS
Master Electrical Component List
Body Control System Description and Operation
Lighting Subsystem References
B+ Bus - Underhood Fuse Block
IGN B Fuse, ACCY/RUN and RUN/START Bus Bars
Crank, IGN 0, TBC ACC, FR WPR, BRKS and HVAC Fuses
IGN B Fuse, ACCY/RUN and RUN/START Bus Bars
Data Link Connector (DLC)
Horns Schematics
Retained Accessory Power (RAP) Schematics
Audible Warning Schematics
Brake Warning System Schematics
Lock and Unlock Control
Switches
Access Panel Relay Control
Theft Deterrent System Schematics
Tow/Haul and Park/Neutral Position Switch Inputs and Vehicle Speed Sensor
Stop Lamp, Tow/Haul, Park/Neutral Position Switch Inputs and Speed Sensors
G303 and G304
Figure 2:

Lighting Subsystem References
Object Number: 1253854 Size: FS
Master Electrical Component List
Body Control System Description and Operation
Power, Ground, Serial Data and Controlled/Monitored Subsystem References
Courtesy Lamps - w/o YF7 - 1 of 2
Courtesy Lamps - YF7
Dome Fluorescent Work Lamps - PRP w/UF2
I/P Dimming Supply Voltage 1 of 3 and LED Dimming Supply Voltage
Dome and Courtesy Lamp Switch Signals and Door Latch Assemblier
Underhood/Vanity Lamps and Rear Door Jamb Switches
Backup (Except Cutaway), Park/Turn, and Marker Lamps
Inside Rearview Mirror Schematics
Headlights Schematics
Headlamp and Panel Dimmer Switch Signals and Park Lamp Relay Control
Dome and Courtesy Lamp Switch Signals and Door Latch Assemblier
Hazard, Turn and Stop Lamp Signals
Headlights Schematics
I/P Dimming Supply Voltage 1 of 3 and LED Dimming Supply Voltage
Headlamp and Panel Dimmer Switch Signals and Park Lamp Relay Control
I/P Dimming Supply Voltage 1 of 3 and LED Dimming Supply Voltage