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

Forward Lamp Harness, Fuse Block-Underhood


Object Number: 748823  Size: MF
(1)C105
(2)Forward Lamp Harness
(3)G101
(4)Brake Fluid Level Connector
(5)G105
(6)G102
Figure 2:

Forward Lamp Harness, Fuse Block-Underhood


Object Number: 748813  Size: MF
(1)G101
(2)Forward Lamp Harness
(3)Fuse Block-Underhood, C4
Figure 3:

Forward Lamp Harness, Front


Object Number: 748819  Size: MF
(1)Ambient Air Temperature Sensor Connector
(2)Forward Lamp Harness
(3)Engine Fan Connector, C118
Figure 4:

Forward Lamp Harness, Right Side


Object Number: 748820  Size: MF
(1)G103
(2)A/C Low Pressure Switch
(3)Winshield Washer Fluid Pump Connectors
(4)Windshield Washer Fluid Level Switch
(5)Forward Lamp Harness
Figure 5:

Engine Harness, Fuse Block-Underhood


Object Number: 748821  Size: MF
(1)C105, I/P to Forward Lamp Harness, Fuse Block-Underhood
(2)C4, Forward Lamp Harness, Fuse Block-Underhood
(3)C3, Chassis Harness, Fuse Block-Underhood
(4)C2, Instrument Panel Harness, Fuse Block-Underhood
(5)C101, I/P to Chassis Harness
(6)C1, Engine Harness, Fuse Block-Underhood
Figure 6:

Engine Harness, Fuse Block-Underhood (Six Cylinder Engine, 4.2L)


Object Number: 748824  Size: MF
(1)PCM
(2)C100, Engine Harness to I/P Harness
(3)C1, Fuse Block-Underhood
(4)PCM Connectors
(5)Engine Harness
Figure 7:

Instrument Harness, Engine Compartment (Six Cylinder Engine, 4.2L)


Object Number: 748860  Size: MF
(1)C104, Engine to Fuel Injector Harness
(2)C100, I/P to Engine Harness
(3)C105, I/P to Forward Lamp Harness
(4)Fuse Block Underhood, C2
(5)C101, Instrument to Chassis Harness
(6)PCM Connector, C1
Figure 8:

Engine Harness Routing - 4.2L (1 of 2)


Object Number: 1332619  Size: LF
(1)Ignition Coil 1
(2)Ignition Coil 2
(3)Ignition Coil 3
(4)Intake Air Temperature (IAT) Sensor
(5)Ignition Coil 4
(6)Ignition Coil 5
(7)C104
(8)Ignition Coil 6
(9)Starter
(10)C175
(11)Heated Oxygen Sensor (HO2S) Sensor 2
(12)Vehicle Speed Sensor (VSS)
(13)Park/Neutral Position (PNP) Switch
(14)Evaporative Emission (EVAP) Canister Purge Solenoid
(15)G107
(16)Manifold Absolute Pressure (MAP) Sensor
(17)Throttle Body
(18)Engine Oil Pressure (EOP) Switch
(19)Camshaft Position (CMP) Sensor
(20)Camshaft Actuator Solenoid Assembly
(21)Heated Oxygen Sensor (HO2S) Sensor 1
Figure 9:

Engine Harness Routing - 4.2L (2 of 2)


Object Number: 1332620  Size: LF
(1)Engine Coolant Temperature (ECT) Sensor
(2)Powertrain Control Module (PCM) Connector C2, C3
(3)C100
(4)Crankshaft Position Sensor (CKP) Sensor
(5)Knock Sensor (KS) 2
(6)G101
(7)Fuse Block - Underhood, Connector C1
(8)Battery Positive
(9)G109
(10)G108
(11)A/C Refrigerant Pressure Sensor
(12)A/C Compressor Clutch Assembly
(13)Battery Negative
(14)Knock Sensor (KS) 1
(15)Generator
Figure 10:

Engine Harness Routing - 5.3L (1 of 2)


Object Number: 1332621  Size: LF
(1)Fuel Injector 4
(2)C108
(3)Evaporative Emission (EVAP) Canister Purge Solenoid
(4)S102
(5)Fuel Injector 3
(6)Engine Coolant Temperature (ECT) Sensor
(7)Throttle Actuator Control (TAC) Module C1
(8)C107
(9)Fuse Block Underhood C1
(10)G107
(11)S101
(12)G108
(13)G109
(14)Powertrain Control Module (PCM) Connector C1, C2
(15)Ignition Coil 5
(16)Crankshaft Position (CKP) Sensor
(17)Starter
(18)A/C Compressor Clutch Assembly
(19)Fuel Injector 6
(20)A/C Refrigerant Pressure Sensor
(21)Fuel Injector 2
(22)Throttle Body
(23)Intake Air Temperature (IAT)/Mass Air Flow (MAF) Sensor
Figure 11:

Engine Harness Routing - 5.3L (2 of 2)


Object Number: 1332623  Size: LF
(1)Generator
(2)Fuel Injector 8
(3)Manifold Absolute Pressure (MAP) Sensor
(4)C115
(5)Fuel Injector 5
(6)Fuel Injector 7
(7)Ignition Coil 7
(8)Heated Oxygen Sensor (HO2S) Bank 1, Sensor 2
(9)C310
(10)Heated Oxygen Sensor (HO2S) Bank 1, Sensor 1
(11)C175
(12)C109
(13)Ignition Coil 1
(14)Fuel Injector 1
(15)Engine Oil Pressure (EOP) Sensor
(16)Heated Oxygen Sensor (HO2S) Bank 2, Sensor 1
Figure 12:

Engine Harness, Automatic Transmission


Object Number: 748827  Size: MF
(1)Engine Harness
(2)Engine Harness
Figure 13:

Engine Harness, Transfer Case


Object Number: 799400  Size: MF
(1)Transfer Case Motor Encoder Connector
(2)C310, Engine to Chassis Harness
(3)Engine Harness
(4)Chassis Harness
Figure 14:

Chassis Harness Routing


Object Number: 1332624  Size: LF
(1)Fuse Block Underhood Eyelet (Trailer Wiring)
(2)Fuse Block Underhood, Connector C3
(3)Fuse Block Underhood, Connector C7
(4)C101
(5)Brake Fluid Level Switch
(6)C310
(7)Propshaft Speed Sensor - Rear
(8)Vehicle Speed Sensor
(9)Fuel Pump and Sender Assembly
(10)Air Suspension - RR
(11)Backup Lamp - Right
(12)Evaporative Emission (EVAP) Canister Vent Solenoid
(13)Fuel Tank Pressure (FTP) Sensor
(14)Air Suspension Compressor Assembly
(15)Trailer Connector
(16)Backup Lamp - Left
(17)S408
(18)G403
(19)Air Suspension Sensor - LR
(20)S306
(21)S359
(22)G305
(23)Electronic Brake Control Module, Connector C1 and C2
(24)Transfer Case Encoder Motor
(25)Propshaft Speed Sensor - Front
(26)G304
(27)Wheel Speed Sensor - LF
(28)Electronic Frontal Sensor - Left
(29)Electronic Frontal Sensor - Right
(30)Front Axle Actuator
(31)Wheel Speed Sensor - RF
Figure 15:

Connector C201


Object Number: 748385  Size: MF
(1)Multi-function Switch
(2)C201
Figure 16:

Front Passenger and Driver Seats


Object Number: 800582  Size: MF
(1)C312
(2)C313
(3)C311
(4)C315
(5)C316
(6)C314
Figure 17:

Underhood Fuse Block


Object Number: 748854  Size: MF
(1)G104
(2)G105
(3)C105, Instrument to Forward Lamp Harness
(4)C101, Instrument to Chassis Harness
(5)G102
(6)Windshield Wiper Connector
Figure 18:

Instrument Harness, Left I/P


Object Number: 748862  Size: MF
(1)Headlamp Switch Connectors
(2)Splice Pack SP205
(3)Grommet
(4)Instrument Panel Harness
Figure 19:

Instrument Harness, Instrument Panel


Object Number: 748865  Size: MF
(1)Connector C203
(2)Accessory Power Connector
(3)Cigar Lighter Connector
(4)Rear Window Wiper/Washer Connector
(5)Headlamp Switch
Figure 20:

Instrument Harness, Console


Object Number: 748867  Size: MF
(1)C307, I/P to Console Harness
Figure 21:

Instrument Panel, Right Side


Object Number: 879165  Size: MF
(1)Instrument Panel
(2)Body Harness
(3)C203, Body Harness
(4)C203, I/P Harness
Figure 22:

Instrument Harness, Floor


Object Number: 748869  Size: MF
(1)SP201, Ground Splice Pack
(2)Instrument Panel Harness
(3)C307, I/P to Console Harness
(4)Sensing and Diagnostic Module Connector
(5)C304, I/P to Body Harness
(6)C301, I/P to Body Harness
Figure 23:

Instrument Harness, Rear Floor


Object Number: 748868  Size: MF
(1)Body Control Module (BCM) Connectors
(2)Fuse Block-Rear, I/P Connector, C1
(3)Fuse Block-Rear, Body Connector, C2
(4)Fuse Block-Rear, Headliner Connector, C3
(5)I/P Harness
(6)VCIM Connectors
(7)Splice Pack SP306
Figure 24:

Floor Console (Long Wheelbase, Body Type VIN 6)


Object Number: 855630  Size: MF
(1)Front Floor Panel
(2)Front Floor Console
(3)Body Harness
(4)C309
Figure 25:

Body Wiring Harness Extension Harness


Object Number: 841111  Size: MF
(1)Body Control Module (BCM)
(2)Body Wiring Harness Extension Harness
(3)Fuse Block-Rear
Figure 26:

Body Harness, Rear Floor


Object Number: 748872  Size: MF
(1)Fuse Block-Rear, Body Connector, C2
(2)C304, Body to Instrument Harness (Short Wheelbase, Body Type VIN 3)
(3)C306 Body to Headliner Harness (Short Wheelbase, Body Type VIN 3)
(4)C301, Body to Instrument Harness (Short Wheelbase, Body Type VIN 3)
(5)Vehicle Communication Interface Module (VCIM) Connectors
Figure 27:

Body Harness, Rear Floor (Long Wheelbase, Body Type VIN 6)


Object Number: 849565  Size: MF
(1)C301
(2)C304
(3)Body Harness
(4)Rear Floor
(5)Instrument Panel Harness
Figure 28:

Body Harness, Left Rear Floor (Long Wheelbase, Body Type VIN 6)


Object Number: 849569  Size: MF
(1)Fuse Block-Rear
(2)Body Harness
(3)Headliner Harness
(4)C306
Figure 29:

Body Harness, C401 (Long Wheelbase, Body Type VIN 6)


Object Number: 872310  Size: MF
(1)Mode Actuator-Auxiliary
(2)Blower-Auxiliary
(3)Air Temperature Actuator-Auxiliary
(4)C401
(5)In-Line 30A Fuse
Figure 30:

Headliner Harness, Overhead Console


Object Number: 795316  Size: MF
(1)Overhead Console
(2)C305
Figure 31:

Headliner Harness, Left B-Pillar


Object Number: 748876  Size: MF
(1)Headliner Harness
(2)Door Frame
(3)G302
Figure 32:

Headliner Harness, Left Rear Floor


Object Number: 748877  Size: MF
(1)C306, Headliner Harness to Body Harness
(2)Fuse Block-Rear, Headliner Connector, C3
(3)Body Harness
(4)Headliner Harness
Figure 33:

Sunroof Harness With Headliner Removed


Object Number: 813455  Size: MF
(1)C308
(2)Sunroof Motor Connector
(3)Connector C1
(4)Sunroof Module
(5)Connector C2
Figure 34:

Front Doors, C500 and C600


Object Number: 1232491  Size: MF
(1)Door, LF
(2)Body Wiring Harness
(3)C500, C600 similar on right side
Figure 35:

Rear Doors, C700 and C800


Object Number: 755998  Size: MF
(1)Door, LR
(2)C700, C800 similar on right side
(3)Body Wiring Harness
Figure 36:

G401, G402


Object Number: 826159  Size: MF
(1)Body Side Lower Reinforcement
(2)Body Harness
(3)G401; G402 Similar on Opposite Side
Figure 37:

Tailgate Connector


Object Number: 755995  Size: MF
(1)Liftgate
(2)C900
(3)Body Opening