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

Power and Ground


Object Number: 775445  Size: FS
Master Electrical Component List
Engine Control Module Description
MIL Control and Serial Data
OBD II Symbol Description Notice
B+ Bus Bar
ECM I, FUEL HT, ENG 1, IGN E, ECMRPV, and INJ B
ECM I, FUEL HT, ENG 1, IGN E, ECMRPV, and INJ B
AIR, RTD, RADIO, RDO AMP, ECM B, FRT HVAC, and CIGAR Fuses
IGN 1, TURN, SEO IGN, AIR BAG, CRANK, and IGN 0 Fuses
G103 and G105 - Gas
IGN 1, TURN, SEO IGN, AIR BAG, CRANK, and IGN 0 Fuses
Figure 2:

MIL Control and Serial Data


Object Number: 775446  Size: FS
Master Electrical Component List
Engine Control Module Description
Engine Data Sensors - Pressure and Temperature
Power and Ground
OBD II Symbol Description Notice
Power, Ground, and Stop Lamp Switch TCC Signal Circuit
Splice Pack SP205
IGN 1, TURN, SEO IGN, AIR BAG, CRANK, and IGN 0 Fuses
AUX PWR and HORN Fuses
Indicators
CAN Serial data, VSS, and PNP Switch
CAN Serial data, VSS, and PNP Switch
Figure 3:

Engine Data Sensors - Pressure and Temperature


Object Number: 775447  Size: FS
Master Electrical Component List
Engine Control Module Description
Engine Data Sensors - EGR and Vacuum - California Emissions Only
MIL Control and Serial Data
OBD II Symbol Description Notice
Ignition, Run, and Start Bus Bar
Engine Data Sensors - EGR and Vacuum - California Emissions Only
Engine Data Sensors - EGR and Vacuum - California Emissions Only
Figure 4:

Engine Data Sensors - EGR and Vacuum - California Emissions only


Object Number: 775451  Size: FS
Master Electrical Component List
Engine Control Module Description
Engine Data Sensors - Pedal Position
Engine Data Sensors - Pressure and Temperature
OBD II Symbol Description Notice
ECM I, FUEL HT, ENG 1, IGN E, ECMRPV, and INJ B
ECM I, FUEL HT, ENG 1, IGN E, ECMRPV, and INJ B
ECM I, FUEL HT, ENG 1, IGN E, ECMRPV, and INJ B
Engine Data Sensors - Pressure and Temperature
Engine Data Sensors - Pressure and Temperature
Figure 5:

Engine Data Sensors - Pedal Position


Object Number: 775453  Size: FS
Master Electrical Component List
Engine Control Module Description
Engine Data Sensors - VSS and Injection Timing Controls
Engine Data Sensors - EGR and Vacuum - California Emissions Only
OBD II Symbol Description Notice
Figure 6:

Engine Data Sensors - VSS and Injection Timing Controls


Object Number: 775455  Size: FS
Master Electrical Component List
Engine Control Module Description
Engine Data Sensors - Glow Plug Controls - Except California Emissions
Engine Data Sensors - Pedal Position
OBD II Symbol Description Notice
Gages
Gages
Vehicle Speed Signal and 4WD Low Signal
Manual Transmission Schematics
G106 - Diesel
Figure 7:

Engine Data Sensors - Glow Plug Controls - All Except California Emissions


Object Number: 775449  Size: FS
Master Electrical Component List
Engine Control Module Description
Engine Data Sensors - Glow Plug Controls - w/California Emissions Only
Engine Data Sensors - VSS and Injection Timing Controls
OBD II Symbol Description Notice
IGN 1, TURN, SEO IGN, AIR BAG, CRANK, and IGN 0 Fuses
AUX PWR and HORN Fuses
Indicators
ECM I, FUEL HT, ENG 1, IGN E, ECMRPV, and INJ B
ECM I, FUEL HT, ENG 1, IGN E, ECMRPV, and INJ B
G304
Figure 8:

Engine Data Sensors - Glow Plug Controls - w/California Emissions Only


Object Number: 775450  Size: FS
Master Electrical Component List
Engine Control Module Description
Fuel Controls - Fuel Pump Controls
Engine Data Sensors - Glow Plug Controls - Except California Emissions
OBD II Symbol Description Notice
IGN 1, TURN, SEO IGN, AIR BAG, CRANK, and IGN 0 Fuses
AUX PWR and HORN Fuses
Indicators
ECM I, FUEL HT, ENG 1, IGN E, ECMRPV, and INJ B
ECM I, FUEL HT, ENG 1, IGN E, ECMRPV, and INJ B
Figure 9:

Fuel Controls - Fuel Pump Controls


Object Number: 775452  Size: FS
Master Electrical Component List
Engine Control Module Description
Fuel Controls - Water In Fuel, Fuel Temperature, and Pressure
Engine Data Sensors - Glow Plug Controls - w/California Emissions Only
OBD II Symbol Description Notice
Fuel Gage and Fuel Pump and Sender Assembly
AIR, RTD, RADIO, RDO AMP, ECM B, FRT HVAC, and CIGAR Fuses
G104 - Gas
G104 - Gas
AIR, RTD, RADIO, RDO AMP, ECM B, FRT HVAC, and CIGAR Fuses
G100 and G110
G401
Figure 10:

Fuel Controls - Water in Fuel, Fuel Temperature, and Fuel Pressure Sensors


Object Number: 775456  Size: FS
Master Electrical Component List
Engine Control Module Description
Fuel Controls - Injector and Pressure Controls
Fuel Controls - Fuel Pump Controls
OBD II Symbol Description Notice
AIR, RTD, RADIO, RDO AMP, ECM B, FRT HVAC, and CIGAR Fuses
B+ Bus Bar
Splice Pack SP205
ECM I, FUEL HT, ENG 1, IGN E, ECMRPV, and INJ B
Figure 11:

Fuel Controls - Injector and Pressure Control


Object Number: 885774  Size: FS
Master Electrical Component List
Engine Control Module Description
Fuel Controls - Fuel injectors
Fuel Controls - Water In Fuel, Fuel Temperature, and Pressure
OBD II Symbol Description Notice
ECM I, FUEL HT, ENG 1, IGN E, ECMRPV, and INJ B
G106 - Diesel
G106 - Diesel
Figure 12:

Fuel Controls - Fuel Injectors


Object Number: 812006  Size: FS
Master Electrical Component List
Engine Control Module Description
Controlled/Monitored Subsystem References
Fuel Controls - Injector and Pressure Controls
OBD II Symbol Description Notice
Figure 13:

Controlled/Monitored Subsystem References


Object Number: 812008  Size: FS
Master Electrical Component List
Engine Control Module Description
Transmission Controls - A/T
Fuel Controls - Fuel injectors
OBD II Symbol Description Notice
A/C Compressor Controls
Compressor Controls
Air Delivery Controls - Recirculation Actuator (Uplevel)
Air Delivery Controls - Actuators
Cruise Control ON/OFF Switch, Clutch Start Switch, Stoplamp Switch - Diesel
Backup Lamps
Charging w/Dual Generator
Charging w/Dual Generator
NP2 Transfercase Schematics
Power, Ground, Class 2 Communication (w/Traction Assist)
Power and Ground
Engine Cooling Schematic
Figure 14:

Transmission Controls - A/T


Object Number: 812011  Size: FS
Master Electrical Component List
Engine Control Module Description
Controlled/Monitored Subsystem References
OBD II Symbol Description Notice
Power, Ground, and Stop Lamp Switch TCC Signal Circuit
Power, Ground, and Stop Lamp Switch TCC Signal Circuit
Power, Ground, and Stop Lamp Switch TCC Signal Circuit
Power, Ground, and Stop Lamp Switch TCC Signal Circuit