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

Module Power, Ground, Serial Data, and MIL


Object Number: 806011  Size: FS
Master Electrical Component List
Engine Control Component Description (Without RPO CTF)
Engine Data Sensors - 5 Volt and Low Reference
Engine Controls Schematic Icons
I/P Fuse Block, START and TRANS Fuses/Circuit Breakers
Underhood Fuse Block, ENGINE Fuse and I/P Fuse Block, PCM-I Fuse/Circuit Breaker
Ignition Switch, OFF/RUN/START, RUN/START, and START Bus Bars
I/P Fuse Block, R-RR TRUCK, L-RR TRUCK, GAGES, and SIR Fuses/Circuit Breaker
Underhood Fuse Block, PCM-B, HTD FUEL, A/C COMP, and RR DEFOG Fuses
Underhood Fuse Block, PCM-B, HTD FUEL, A/C COMP, and RR DEFOG Fuses
Instrument Panel Cluster - 2 of 2
Electronic Fan Controls, Coolant Level Switch
Engine Data Sensors - Glow Plug Controls
G103 - 1 of 2, G105, and G106
G103 - 2 of 2
Splice Pack SP203 (L18/LB7/LG4)
Figure 2:

Engine Data Sensors - 5-Volt and Low Reference


Object Number: 806021  Size: FS
Master Electrical Component List
Engine Control Component Description (Without RPO CTF)
Engine Data Sensors - Pressure and Temperature
Module Power, Ground, Serial Data, and MIL
Engine Controls Schematic Icons
Figure 3:

Engine Data Sensors - Pressure and Temperature Sensors


Object Number: 806029  Size: FS
Master Electrical Component List
Fuel System Description (Without RPO CTF)
Engine Data Sensors - Glow Plug Controls
Engine Data Sensors - 5 Volt and Low Reference
Engine Controls Schematic Icons
Instrument Panel Cluster - 1 of 2
Fuel Senders
Figure 4:

Engine Data Sensors - Pedal Position


Object Number: 806196  Size: FS
Master Electrical Component List
Engine Control Component Description (Without RPO CTF)
Fuel Controls - Fuel Injectors
Engine Data Sensors - Glow Plug Controls
Engine Controls Schematic Icons
Ignition Switch, RUN and ACC/RUN Bus Bars
BRAKE, CHASSIS, HTR/AC, and AXLE/4WD Fuses/Circuit Breakers
G101 - 2 of 2
Figure 5:

Fuel Controls Water In Fuel/Temperature Sensors


Object Number: 1348087  Size: FS
Master Electrical Component List
Fuel System Description (Without RPO CTF)
Fuel Controls - Fuel Injectors
Engine Data Sensors - Glow Plug Controls
Engine Controls Schematic Icons
Underhood Fuse Block, ENG 3, O2A, and ENG 2 Fuses (LG4)
B+ Bus Bar
Ignition Switch, OFF/RUN/START, RUN/START, and START Bus Bars
Underhood Fuse Block, ENG 3, O2A, and ENG 2 Fuses (LG4)
I/P Fuse Block, R-RR TRUCK, L-RR TRUCK, GAGES, and SIR Fuses/Circuit Breaker
Driver Information Center (DIC)
G103 - 1 of 2, G105, and G106
G118, G119, and G120
Figure 6:

Engine Data Sensors - Glow Plugs Controls


Object Number: 806030  Size: FS
Master Electrical Component List
Glow Plug System Description
Engine Data Sensors - Pedal Position
Engine Data Sensors - Pressure and Temperature
Engine Controls Schematic Icons
Ignition Switch, OFF/RUN/START, RUN/START, and START Bus Bars
I/P Fuse Block, R-RR TRUCK, L-RR TRUCK, GAGES, and SIR Fuses/Circuit Breaker
Module Power, Ground, Serial Data, and MIL
Module Power, Ground, Serial Data, and MIL
Module Power, Ground, Serial Data, and MIL
Figure 7:

Fuel Controls - Fuel Injectors


Object Number: 806039  Size: FS
Master Electrical Component List
Fuel System Description (Without RPO CTF)
Fuel Tank Senders
Engine Data Sensors - Pedal Position
Engine Controls Schematic Icons
FUEL Fuse/Circuit Breaker (L18/LB7), PCV Circuit Breaker (LG4), and ECM-B Circuit Breaker (LG5)
Underhood Fuse Block, ENG4 and ENG1 Fuses (LG4/LG5)
Figure 8:

Controlled/Monitored Subsystem References


Object Number: 806062  Size: FS
Master Electrical Component List
Engine Control Component Description (Without RPO CTF)
Controlled/Monitored Subsystem References
Fuel Tank Senders
Engine Controls Schematic Icons
Power Takeoff (LG4/L18/LB7) - 1 of 2
Power Takeoff (LG4/L18/LB7) - 1 of 2
Figure 9:

Controlled/Monitored Subsystems References


Object Number: 806066  Size: FS
Master Electrical Component List
Engine Control Component Description (Without RPO CTF)
Controlled/Monitored Subsystem Reference
Engine Controls Schematic Icons
Instrument Panel Cluster - 2 of 2
Engine Exhaust System
Electronic Fan Controls, Coolant Level Switch
Cruise Control Switch (L18/LB7)
Starting System (L18/LB7)
Backup Lamps
Blower Controls (C60)
Traction Control and Brake Lamp Switch
Two Speed Axle Controls