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

OnStar Component Locations - Typical


Object Number: 623162  Size: MF
(1)Global Positioning Satellite (GPS) Antenna
(2)Cellular Telephone Microphone
(3)Global Positioning System (GPS)
(4)Relay Block - Body
(5)Vehicle Communication Unit (VCU)
(6)OnStar Button Assembly
(7)Vehicle Interface Unit (VIU)
Figure 2:

LH Front of Vehicle - Typical


Object Number: 310802  Size: MF
(1)Upper Radiator Support (Tie Bar)
(2)Headlamp Assembly-LF
(3)Headlamp - High Beam - Left Connector
(4)Daytime Running Lamp (DRL)-Left
(5)Daytime Running Lamp (DRL)-Left Socket
(6)Windshield Washer Reservoir
(7)Park/Turn Signal Lamp Socket-LF
(8)Marker Lamp Socket-LF
(9)Marker Lamp-LF
(10)Park/Turn Signal Lamp-LF
(11)Snowplow (Option) Connector C125
(12)Headlamp Connector-Low Beam-Left
(13)Marker Lamp-LF
Figure 3:

Fuse Block - Underhood


Object Number: 310806  Size: MF
(1)Fuse Block - Underhood Bracket
(2)Inflatible Restraint Harness
(3)Radiator Support
(4)C103 -I/P Harness Side
(5)C103 -Forward Lamp Harness Side
(6)LH Battery Tray
(7)Fuse Block - Underhood Bracket
(8)Fuse Block - Underhood
Figure 4:

C100, C102 and C152


Object Number: 413351  Size: MF
(1)C102
(2)Fuse Block - Underhood Support Mount
(3)C152
(4)C100
Figure 5:

C104, C114, C150, C151, C153, C154, and PTO Relay


Object Number: 814636  Size: LF
(1)Fuse Block - Underhood
(2)C153 - Engine Harness to Transfer Case Harness
(3)C150 - Transfer Case Harness to Axle Jumper Harness
(4)Transfer Case Harness
(5)C151 - I/P Harness to Automatic Transfer Case Harness (w/NP8/NR4) or C104 - I/P Harness to Forward Lamp Harness (w/o NP8/NR4)
(6)C154 - I/P Harness to Automatic Transfer Case Harness (w/NP8/NR4) or C114 - Chassis Harness to I/P Harness (w/JL4/NYS)
(7)Power Take-Off (PTO) Relay
Figure 6:

Engine Harness - 4.3L


Object Number: 1402445  Size: LF
(1)Intake Air Temperature (IAT)/ Mass Air Flow (MAF) Sensor Connector
(2)Generator Connector
(3)Coolant Level Switch Connector
(4)Manifold Absolute Pressure (MAP) Sensor Connector
(5)A/C Low Pressure Switch Connector
(6)Auxiliary Battery Relay Connector (TP2)
(7)S102
(8)S103
(9)Heated Oxygen Sensor (HO2S) Bank 2 Sensor 1 Connector
(10)Heated Oxygen Sensor (HO2S) Bank 2 Sensor 2 Connector
(11)Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2 Connector
(12)Vehicle Speed Sensor (VSS)
(13)Backup Lamp Switch (Manual Trans)
(14)Heated Oxygen Sensor (HO2S) Bank 1 Sensor 1 Connector
(15)Camshaft Position (CMP) Sensor Connector
(16)Engine Oil Pressure (EOP) Sensor Connector
(17)Engine Coolant Temperature (ECT) Sensor Connector
(18)Idle Air Control (IAC) Motor Connector
(19)S110
(20)Throttle Position (TP) Sensor Connector
(21)C153
(22)C100
(23)Fuse Block - Underhood C2
(24)C152
(25)Powertrain Control Module (PCM) C2
(26)Powertrain Control Module (PCM) C1
(27)A/C Compressor Clutch Connector
(28)A/C Refrigerant Pressure Sensor Connector
Figure 7:

Primary Negative Battery Ground and G105 (6.6L)


Object Number: 768351  Size: MF
(1)Engine - 6.6L Diesel
(2)Primary Negative Battery Cable
(3)Primary Negative Battery Ground
(4)G105
(5)Engine Harness
Figure 8:

Lower Right Side of the Engine (6.6L)


Object Number: 768355  Size: MF
(1)Engine - 6.6L Diesel
(2)Engine Harness
(3)G102
(4)Auxiliary Negative Battery Ground
(5)Starter Relay Terminal
(6)Starter Solenoid
Figure 9:

C201 and A/T Shift Lock Control Connector


Object Number: 310109  Size: MF
(1)Inline Connector C201
(2)Inline Connector C201
(3)Inflatable Restraint Harness
(4)Inflatable Restraint Electrical Connector
(5)Body Control Module (BCM) Bracket
(6)Body Control Module (BCM) Harness
(7)A/T Shift Lock Control Solenoid Connector
(8)A/T Shift Lock Control Solenoid Electrical Connector
(9)Lower Steering Column Shaft
(10)Inflatable Restraint Steering Wheel Module Connector with Tether
(11)Instrument Panel Bracket
Figure 10:

Instrument Cluster


Object Number: 310124  Size: MF
(1)Instrument Panel Cluster (IPC)
(2)Inline Connector C202 M
(3)Inline Connector C202 F
(4)Instrument Cluster Electrical Connector
(5)Instrument Panel Carrier
(6)Instrument Panel
Figure 11:

Instrument Panel Harness Routing View


Object Number: 574009  Size: LF
(1)Instrument Panel
(2)Instrument Panel Cluster Connector
(3)Sunload Sensor
(4)Radio Connectors
(5)Daytime Running Lamps (DRL) Sensor
(6)Air Temperature Sensor - Upper
(7)Passenger Inflatable Restraint Module Connector
(8)Inflatable Restraint Module Switch Connector
(9)Inline Connector C206
(10)Inline Connector C207
(11)Speaker Connector
(12)Compartment Lamp Connector
(13)Fuse Block - Right I/P
(14)Inline Connector to RH Door Harness
(15)Inline Connector to RH Body Harness-06 only
(16)Ashtray Lamp Connector
(17)HVAC Control Module Connectors
(18)Cigarette Lighter Connector
(19)Power Accessary Connectors
(20)Inline Connector C352
(21)Inline Connector C307
(22)Steering Column Connector
(23)Inline Connector C340
(24)Body Control Module Connectors
(25)Cargo/Fog Switch Connector
(26)Headlamp Switch Connector
(27)Steering Column -SIR Connector
(28)Fuse Block
(29)Data Link Communication Connector
(30)Inflatable Restraint Sensing And Diagnostic Module (SDM) Connector
(31)Inline Connector C204
(32)Inline Connector C200
(33) Courtesy Lamp - Left
(34)Relay Block - Body
(35)Splice Pack SP203
(36)Inline Connectors to Automatic Transfer Case -C151 C153
(37)Inline Connector C102- I/P to Chassis Harness
(38)Inline Connector C103 -I/P to Forward Lamp Harness
(39)Fuse Block-Underhood
(40)Instrument Panel Battery Feed Connectors
(41)Trailer Power Feed Connector
(42)Cruise Control/Throttle Actuator Connector
(43)Underhood Lamp Connector
(44) Speaker - Left Connector
(45)Inline Connector C204 -I/P to LH Body Harness
(46)Underhood Lamp Ground
(47)I/P Harness to Plenum Ground
(48)Windshield Wiper System Module Connector
Figure 12:

Chassis Wiring Harness to Front Frame -25 Series


Object Number: 615810  Size: MF
(1)Shock Absorber Solenoid-LF Connector
(2)Wheel Speed Sensor (WSS)-LF Connector
(3)Wheel Speed Sensor (WSS)-LF Connector
(4)Suspension Position Sensor-LF Connector
(5)Suspension Position Sensor-LF Connector
(6)Chassis Harness
(7)Shock Absorber Solenoid-RF Connector
(8)Shock Absorber Solenoid-RF Connector
(9)Suspension Position Sensor-RF Connector
(10)Frame
Figure 13:

HVAC Module Assembly Connections, C296 and G200


Object Number: 310004  Size: MF
(1)Recirculation Actuator Connector
(2)Instrument Panel
(3)Electrical Harness Connector
(4)G200
(5)Blower Motor Resistor Assembly
(6)Blower Motor Resistor Connector
(7)C296
(8)Air Temperature Actuator Connector
(9)Air Temperature Actuator
(10)Mode Actuator
Figure 14:

Headliner Harness to Relay Block - Body


Object Number: 623107  Size: MF
(1) A - Pillar
(2)Headliner Wiring Harness
(3)Relay Block - Body
(4)Headliner Harness Connector C-6
Figure 15:

C200 and C204


Object Number: 310055  Size: MF
(1)C200 -I/P Harness Side
(2)C204
(3)A-Pillar
(4)C200 -Door Harness Side
Figure 16:

C208 and C299


Object Number: 617242  Size: MF
(1)Side Cowl Panel
(2)C299 -Door Harness Side
(3)C299 -I/P Harness Side
(4)C208 -Right Body Harness Side
(5)C208 -I/P Harness Side
Figure 17:

C210 and Relay Block-Body-C4


Object Number: 814939  Size: LF
(1)Relay Block-Body
(2)Relay Block-Body-C4
(3)C210-Roof Beacon Relay Inline
Figure 18:

C304 and C299


Object Number: 656720  Size: MF
(1)Fuse Block - Right I/P
(2)Fuse Block - Right I/P- C2
(3)RF Door Harness
(4)C304
(5)C299
Figure 19:

LH Rear of Passenger Compartment


Object Number: 309982  Size: MF
(1) Side Inner Body Panel - LH
(2)Panel Access Hole
(3) Speaker - LR Connector
(4)Speaker - LR Connector
(5)Body Wiring Harness
(6)Body Wiring Harness
(7)Rear Glass -Defogger Grid Not Shown
(8)Rear Defogger Grid Connector
(9)Rear Defogger Grid Connector
Figure 20:

Driver/Passenger Power Seat Wiring -C301, C305 and C399


Object Number: 656608  Size: MF
(1)C305
(2)C399
(3)Power Seat Wiring Harness to Heated Seat Switch
(4)C301
Figure 21:

Driver Seat (w/Memory -- 1 of 2)


Object Number: 784811  Size: MF
(1)Inline Connector C324
(2)Memory Seat Module-C2
(3)Memory Seat Module-C1
(4)Memory Seat Module
(5)Inline Connector C321
(6)Inline Connector C320
(7)Memory Seat Module-C3
(8)Positive Temperature Coefficient (PTC) Thermistor
(9)Inline Connector C305
(10)Inflatible Restraint Side Impact Sensor (SIS) - Left Connector
(11)Inline Connector C323
(12)Inline Connector C325
(13)Inline Connector C322
(14)Heated Seat Relay and Logic
(15)Seat Belt Switch Connector
(16)Seat Heater Element Connector