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

Power and Ground


Object Number: 885751  Size: FS
Master Electrical Component List
Engine Control Module Description
MIL Control and Serial Data
OBD II Symbol Description Notice
B+ Bus Bar (Diesel) - 2 of 3
ECM, ECMRPV, EDU, EDU Relay - Diesel Only
IGN 1 Relay Bus, SEO 2, RR DEFOG, SEO IGN, B/U LP
ECM, ECMRPV, EDU, EDU Relay - Diesel Only
IGN 0 , TBC IGN 0, TBC ACCY, SEO ACCY, W/S WIPER, RR WIPER
IGN 0 , TBC IGN 0, TBC ACCY, SEO ACCY, W/S WIPER, RR WIPER
FUEL HT and ECM I Fuses - Diesel Only
G102, G103-Gas
Figure 2:

MIL Control and Serial Data


Object Number: 885755  Size: FS
Master Electrical Component List
Engine Control Module Description
Engine Data Sensors - Pressure and Temperature
Power and Ground
OBD II Symbol Description Notice
SP205 - 2 of 2
B+ Bus Bar (Gas) - 1 of 3
RTD/ECAS, RR WPR, EAP, SUNROOF, IPC/DIC, SEO 1
Power, Ground, Serial Data
CAN Serial Data, VSS, and PNP Switch
CAN Serial Data, VSS, and PNP Switch
Figure 3:

Engine Data Sensors - Pressure and Temperature


Object Number: 885757  Size: FS
Master Electrical Component List
Engine Control Module Description
Engine Data Sensors - EGR and Vacuum
MIL Control and Serial Data
OBD II Symbol Description Notice
IGN 1 Relay Bus, SEO 2, RR DEFOG, SEO IGN, B/U LP
SBA, ETC, PCM 1, BTSI, TRL B/U
Engine Data Sensors - EGR and Vacuum
Engine Data Sensors - EGR and Vacuum
Figure 4:

Engine Data Sensors - EGR and Vacuum


Object Number: 885759  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
Ignition, Run, Start, Accy Bus Bar
Engine Data Sensors - Pressure and Temperature
Engine Data Sensors - Pressure and Temperature
FUEL HT and ECM I Fuses - Diesel Only
FUEL HT and ECM I Fuses - Diesel Only
Figure 5:

Engine Data Sensors - Pedal Position


Object Number: 885761  Size: FS
Master Electrical Component List
Engine Control Module Description
VSS and Injection Timing Controls
Engine Data Sensors - EGR and Vacuum
OBD II Symbol Description Notice
Figure 6:

Engine Data Sensors - VSS and Injection Timing Controls


Object Number: 885764  Size: FS
Master Electrical Component List
Engine Control Module Description
Data Sensors - Glow Plug Controls - Except California Emissions
Engine Data Sensors - Pedal Position
OBD II Symbol Description Notice
Gauges, VSS, Engine Oil Signals-Diesel Only
Gauges, VSS, Engine Oil Signals-Diesel Only
CAN Serial Data, VSS, and PNP Switch
Manual Transmission Schematics
G104, G106, G107
Figure 7:

Engine Data Sensors - Glow Plug Controls - Except California Emissions


Object Number: 885766  Size: FS
Master Electrical Component List
Engine Control Module Description
Engine Data Sensors - Glow Plug Controls - California Emissions
VSS and Injection Timing Controls
OBD II Symbol Description Notice
Ignition, Run, Start, Accy Bus Bar
FUEL HT and ECM I Fuses - Diesel Only
Ignition, Run, Start, Accy Bus Bar
Ignition, Run, Start, Accy Bus Bar
Indicators, DIC Controls, Washer Fluid Level Sensor
G104, G106, G107
Figure 8:

Engine Data Sensors - Glow Plug Controls - California Emissions


Object Number: 885769  Size: FS
Master Electrical Component List
Engine Control Module Description
Fuel Controls - Fuel Pump Controls
Data Sensors - Glow Plug Controls - Except California Emissions
OBD II Symbol Description Notice
Ignition, Run, Start, Accy Bus Bar
Ignition, Run, Start, Accy Bus Bar
FUEL HT and ECM I Fuses - Diesel Only
B+ Bus Bar (Gas) - 1 of 3
Ignition, Run, Start, Accy Bus Bar
Indicators, DIC Controls, Washer Fluid Level Sensor
Figure 9:

Fuel Controls - Fuel Pump Controls


Object Number: 885771  Size: FS
Master Electrical Component List
Engine Control Module Description
Fuel Controls - Water in Fuel, Fuel Temperature, and Fuel Pressure Sensors
Engine Data Sensors - Glow Plug Controls - California Emissions
OBD II Symbol Description Notice
B+ Bus Bar (Diesel) - 2 of 3
G102, G103, G108, and G109 - Diesel
G102, G103, G108, and G109 - Diesel
Fuel Gauge-Gas Only
G102, G103, G108, and G109 - Diesel
G110
ECM, ECMRPV, EDU, EDU Relay - Diesel Only
G403
Figure 10:

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


Object Number: 885772  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
QS4, RADIO, RDO AMP
Ignition, Run, Start, Accy Bus Bar
FUEL HT and ECM I Fuses - Diesel Only
G102, G103-Gas
SP205 - 2 of 2
G102, G103-Gas
Figure 11:

Fuel Controls - Injector and Pressure Controls


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 Fuel Pressure Sensors
OBD II Symbol Description Notice
Ignition, Run, Start, Accy Bus Bar
Figure 12:

Fuel Controls - Fuel Injectors


Object Number: 885776  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: 885777  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
A/C Compressor Controls
A/C Compressor Controls
A/C Compressor Controls
Backup Lamps - Chevrolet
Charging System-Diesel
Charging System-Diesel
Transfer Case Schematics - NP1
Power, Ground, and Transfer Case Encoder Motor
Over 8600 GVW - 2 of 2
Over 8600 GVW - 2 of 2
Gauges, VSS, Engine Oil Signals-Diesel Only
Engine Cooling
Figure 14:

Transmission Controls - A/T


Object Number: 885779  Size: FS
Master Electrical Component List
Engine Control Module Description
Controlled/Monitored Subsystem References
OBD II Symbol Description Notice
CAN Serial Data, VSS, and PNP Switch
CAN Serial Data, VSS, and PNP Switch
CAN Serial Data, VSS, and PNP Switch
Serial Data, Tow/Haul Switch, and Torque Signals