GM Service Manual Online
For 1990-2009 cars only

Name

Location

Locator View

Connector End View

Automatic Engine Shutdown/ Engine Coolant Temperature (ECT) Switch (Cat® Diesel)

On the right side of the engine, on the left rear side of the coolant outlet housing

Engine Controls Component Views in Engine Controls 7.2L (Caterpillar®)

Engine Controls Connector End Views in Engine Controls 7.2L (Caterpillar®)

Automatic Transmission (AT) Oil Temperature Gauge Sensor

On the lower right rear of the radiator, on the transmission oil cooler inlet fitting

Instrument Panel, Gages, and Console Component Views

Instrument Panel, Gages, and Console Connector End Views

Brake Fluid Level Switch

On the left side of the brake master cylinder reservoir

Instrument Panel, Gages, and Console Component Views

Instrument Panel, Gages, and Console Connector End Views

Daytime Running Lights (DRL) Control Module

On the left kick panel, in the DRL harness

Lighting Systems Component Views in Lighting Systems

Lighting Systems Connector End Views in Lighting Systems

Driver Information Center (DIC) (Cat® Diesel)

On the left side of the IP, part of the instrument panel cluster (IPC)

Instrument Panel, Gages, and Console Component Views

Instrument Panel, Gages, and Console Connector End Views

C1 (11 cavities)

In the IP harness, to the DIC

Instrument Panel, Gages, and Console Component Views

Instrument Panel, Gages, and Console Connector End Views

C2 (11 cavities)

In the IP harness, to the DIC

Instrument Panel, Gages, and Console Component Views

Instrument Panel, Gages, and Console Connector End Views

Driver Information Center (DIC) (Gasoline)

On the left side of the IP, part of the instrument panel cluster (IPC)

Instrument Panel, Gages, and Console Component Views

Instrument Panel, Gages, and Console Connector End Views

C1 (11 cavities)

In the IP harness, to the DIC

Instrument Panel, Gages, and Console Component Views

Instrument Panel, Gages, and Console Connector End Views

C2 (11 cavities)

In the IP harness, to the DIC

Instrument Panel, Gages, and Console Component Views

Instrument Panel, Gages, and Console Connector End Views

C1 (11 cavities)

In the IP harness, to the DIC

Instrument Panel, Gages, and Console Component Views

Instrument Panel, Gages, and Console Connector End Views

C2 (11 cavities)

In the IP harness, to the DIC

Instrument Panel, Gages, and Console Component Views

Instrument Panel, Gages, and Console Connector End Views

Electronic Brake Control Module (EBCM) (ABS-Air)

On a bracket, on the left side, upper exterior bulkhead, on the top of the air brake application valve

Air Antilock Brake System Component Views in Air Antilock Brake Systems

Air Antilock Brake System Connector End Views in Air Antilock Brake Systems

C1 (30 cavities)

In the electronic brake control harness, to the EBCM

Air Antilock Brake System Component Views in Air Antilock Brake Systems

Air Antilock Brake System Connector End Views in Air Antilock Brake Systems

C2 (18 cavities)

In the electronic brake control harness, to the EBCM

Air Antilock Brake System Component Views in Air Antilock Brake Systems

Air Antilock Brake System Connector End Views in Air Antilock Brake Systems

Electronic Brake Control Module (EBCM) (ABS-Hydraulic)

On the inboard side of the left frame rail, to the rear of number one crossmember, on the bracket

Antilock Brake System Component Views in Antilock Brake Systems

Antilock Brake System Connector End Views in Antilock Brake Systems

C1 (2 cavities)

In the electronic brake control harness, to the EBCM

Antilock Brake System Component Views in Antilock Brake Systems

Antilock Brake System Connector End Views in Antilock Brake Systems

C2 (24 cavities)

In the electronic brake control harness, to the EBCM

Antilock Brake System Component Views in Antilock Brake Systems

Antilock Brake System Connector End Views in Antilock Brake Systems

Engine Coolant Temperature (ECT) Gauge Sensor (Cat® Diesel)

On the right side of the engine, on the right rear side of the coolant outlet housing

Instrument Panel, Gages, and Console Component Views

Instrument Panel, Gages, and Console Connector End Views

Engine Coolant Temperature (ECT) Gauge Sensor (Gasoline)

In the right hand cylinder head, above the spark plugs, between the #5 and #7 cylinder

Instrument Panel, Gages, and Console Component Views

Instrument Panel, Gages, and Console Connector End Views

Engine Oil Pressure (EOP) Gauge Sensor and Fuel Pump (FP) Switch (Gasoline)

On the top rear of the engine, behind the intake manifold

Instrument Panel, Gages, and Console Component Views

Instrument Panel, Gages, and Console Connector End Views

Engine Oil Pressure (EOP) Gauge Sensor and Fuel Pump (FP) Switch (Gasoline)

On the top rear of the engine near the bell housing

Engine Controls Component Views in Engine Controls-7.4L

Engine Controls Connector End Views in Engine Controls-7.4L

Fuel Sender and Fuel Pump (FP) (Gasoline)

On the outboard side of the left frame rail, in the fuel tank

Engine Controls Component Views in Engine Controls-7.4L

Engine Controls Connector End Views in Engine Controls-7.4L

Fuel Sender and Fuel Pump (FP) (Gasoline)

On the outboard side of the left frame rail, in the fuel tank

Instrument Panel, Gages, and Console Component Views

Instrument Panel, Gages, and Console Connector End Views

Generator (Cat® Diesel)

On the right side of the engine

Engine Electrical Component Views in Engine Electrical

Engine Electrical Connector End Views in Engine Electrical

C1 (ring terminal)

In the engine harness, to the generator Bat terminal

Engine Electrical Component Views in Engine Electrical

Engine Electrical Connector End Views in Engine Electrical

C2 (ring terminal)

In the engine harness, to the generator R terminal

Engine Electrical Component Views in Engine Electrical

Engine Electrical Connector End Views in Engine Electrical

C3 (2 cavities)

In the engine harness, to the generator

Engine Electrical Component Views in Engine Electrical

Engine Electrical Connector End Views in Engine Electrical

Generator (Gasoline)

On the upper right side of the engine

Engine Electrical Component Views in Engine Electrical

Engine Electrical Connector End Views in Engine Electrical

C1 (ring terminal)

In the engine harness, to the generator Bat terminal

Engine Electrical Component Views in Engine Electrical

Engine Electrical Connector End Views in Engine Electrical

C2 (4 cavities)

In the engine harness, to the generator

Engine Electrical Component Views in Engine Electrical

Engine Electrical Connector End Views in Engine Electrical

C1 (ring terminal)

In the engine harness, to the generator Bat terminal

Engine Electrical Component Views in Engine Electrical

Engine Electrical Connector End Views in Engine Electrical

C2 (4 cavities)

In the engine harness, to the generator

Engine Electrical Component Views in Engine Electrical

Engine Electrical Connector End Views in Engine Electrical

Hourmeter

On the left side of the IP, to the right of the steering column, on the center accessory trim plate, the top gauge

Instrument Panel, Gages, and Console Component Views

Instrument Panel, Gages, and Console Connector End Views

IP Fuse Block

In the center of the IP, to the left of the instrument panel cluster (IPC)

Power and Grounding Component Views in Wiring Systems

Power and Grounding Connector End Views in Wiring Systems

Instrument Panel Cluster (IPC)

In the left side of the IP

Instrument Panel, Gages, and Console Component Views

Instrument Panel, Gages, and Console Connector End Views

Low Air Pressure Switch

Under the IP, above the accelerator pedal

Air Brake System Component Views in Air Brakes

Air Brake System Connector End Views in Air Brakes

Low Air Pressure Switch

Under the IP, above the accelerator pedal

Instrument Panel, Gages, and Console Component Views

Instrument Panel, Gages, and Console Connector End Views

MaxiFuse® Block/ Mini-Relay Center

On the right side of the IP, under the access cover

Power and Grounding Component Views in Wiring Systems

Power and Grounding Connector End Views in Wiring Systems

Multifunction Alarm Module (MFAM) (Cat® Diesel)

In the center of the IP harness, behind the right access panel

Engine Controls Component Views in Engine Controls 7.2L (Caterpillar®)

Engine Controls Connector End Views in Engine Controls 7.2L (Caterpillar®)

C1 (16 cavities)

In the IP harness, to the MFAM

Engine Controls Component Views in Engine Controls 7.2L (Caterpillar®)

Engine Controls Connector End Views in Engine Controls 7.2L (Caterpillar®)

C2 (4 cavities) (with Automatic Engine Shutdown)

In the IP harness to the MFAM

Engine Controls Component Views in Engine Controls 7.2L (Caterpillar®)

Engine Controls Connector End Views in Engine Controls 7.2L (Caterpillar®)

Multifunction Alarm Module (MFAM) (Gasoline)

In the center of the IP, behind the right access panel

Engine Controls Component Views in Engine Controls-7.4L

Engine Controls Connector End Views in Engine Controls-7.4L

Park Brake Switch (ABS-Air)

On the right side of the IP, on the park brake valve

Lighting Systems Component Views in Lighting Systems

Lighting Systems Connector End Views in Lighting Systems

Park Brake Switch (ABS-Air)

On the right side of the IP, on the park brake valve

Lighting Systems Component Views in Lighting Systems

Lighting Systems Connector End Views in Lighting Systems

Park Brake Switch (ABS Hydraulic)

On the left kick panel, to the right rear of the park brake lever

Instrument Panel, Gages, and Console Component Views

Instrument Panel, Gages, and Console Connector End Views

Park Brake Switch (ABS Hydraulic)

On the left kick panel, to the right rear of the park brake lever

Instrument Panel, Gages, and Console Component Views

Instrument Panel, Gages, and Console Connector End Views

Powertrain Control Module (PCM) (Cat® Diesel)

On the left rear side of the engine block

Engine Controls Component Views in Engine Controls-7.2L (Caterpillar®)

Engine Controls Connector End Views in Engine Controls-7.2L (Caterpillar®)

Powertrain Control Module (PCM) (Gasoline)

Under the left front cowel in front of driver

Engine Controls Component Views in Engine Controls-7.4L

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Powertrain Control Module (PCM) - C1 (Gasoline) (32 cavities)

Under the left front cowel in front of driver

Engine Controls Component Views in Engine Controls-7.4L

Engine Controls Connector End Views in Engine Controls-7.4L

Powertrain Control Module (PCM) - C2 (Gasoline) (24 cavities)

Under the left front cowel in front of driver

Engine Controls Component Views in Engine Controls-7.4L

Engine Controls Connector End Views in Engine Controls-7.4L

Speedo Adapter

In the right side of the IP under the MaxiFuse® block/ mini-relay center

Instrument Panel, Gages, and Console Component Views

Engine Electrical Connector End Views in Engine Electrical

C109 (8 cavities) (gasoline)

Engine harness to the odd bank (left side) ignition coil harness

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Inline Harness Connector End Views in Wiring Systems

C110 (10 cavities) (gasoline)

Engine harness to the even bank (right side) ignition coil harness

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Inline Harness Connector End Views in Wiring Systems

C116 (5 cavities) (Cat® Diesel)

In the engine harness, to the fuel tank harness, at the right frame rail, near the starter

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Inline Harness Connector End Views in Wiring Systems

C116 (5 cavities) (Gasoline)

In the engine harness at the right frame rail, near the starter

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Inline Harness Connector End Views in Wiring Systems

C119 (7 cavities) (Cat® Diesel)

In the ABS-hydraulic jumper harness, to the ABS-hydraulic chassis harness, in the engine compartment, on the left side of the bulkhead

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Inline Harness Connector End Views in Wiring Systems

C119 (7 cavities) (Gasoline)

In the engine harness, to the ABS-hydraulic chassis harness, in the engine compartment, on the left side of the bulkhead

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Inline Harness Connector End Views in Wiring Systems

C127 (Cat® Diesel

On the engine harness, to the Cat® diesel engine harness, near the air intake heater relay

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Inline Harness Connector End Views in Wiring Systems

C127

On the engine harness, to the fuel injector harness, at the rear of the engine

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Inline Harness Connector End Views in Wiring Systems

C200 (56 cavities) (Cat® Diesel)

In the IP harness, to the engine harness, under the right side of the IP

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Inline Harness Connector End Views in Wiring Systems

C200 (56 cavities) (Gasoline)

In the IP harness, to the engine harness, under the right side of the IP

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Inline Harness Connector End Views in Wiring Systems

C210

In the right center of the dash, behind IP fuse block

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Inline Harness Connector End Views in Wiring Systems

C232 (3 cavities) (ABS-Hydraulic)

In the IP harness, inline to the ABS-hydraulic brake harness, near the left side of the interior bulkhead

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Inline Harness Connector End Views in Wiring Systems

C233 (2 cavities) (ABS-Hydraulic)

In the IP harness, inline to the ABS-hydraulic brake harness, near the left side of the interior bulkhead

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Inline Harness Connector End Views in Wiring Systems

C234 (7 cavities) (ABS-Hydraulic)

In the IP harness, inline to the ABS-hydraulic brake harness, near the left side of the interior bulkhead

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Inline Harness Connector End Views in Wiring Systems

D200 (Charge Indicator Diode) (Cat® Diesel)

In the IP harness, in the main harness, the in-line generator diode, approximately 4 cm (2 in) to the left of the data link connector (DLC) breakout

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D201 (ABS Diode) (ABS-Hydraulic)

In the IP harness, approximately 4 cm (2 in) from the MaxiFuse® block/ mini-relay center

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G101 (Cat® Diesel)

From the starter motor end ground stud (G101) to the right frame rail ground (G100)

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G102 (Cat® Diesel)

From the engine harness, to the lower right front side of the engine

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G102 (Gasoline)

From the engine harness, to the back of the left cylinder head

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G117 (Cat® Diesel)

The engine harness ground and generator ground strap, at the right side of the engine (G117) to the generator (G119)

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G117 (Gasoline)

The generator ground strap, from the right side of the engine (G117) to the generator (G119)

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G401

From the negative battery cable to the right frame rail

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P100

On the right side of the bulkhead

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P102

On the right side of the bulkhead

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P103

On the left side of the bulkhead

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S138

In the engine harness, approximately 4 cm (2 in) from the generator harness breakout

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S138 (Cat® Diesel)

In the engine harness, approximately 11 cm (4 in) from the main harness, toward the forward lamps harness connector

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S141

In the engine harness, approximately 17 cm (7 in) throttle position (TP), from generator harness breakout

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S142 (Gasoline)

In the engine harness, approximately 4 cm (2 in) from the throttle position (TP) sensor, toward the breakout

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S142 (Cat® Diesel)

In the engine harness, approximately 4 cm ( in)

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S210

In the IP harness, approximately 4 cm (2 in) to the right of the hazard warning switch breakout

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S211

In the IP harness, approximately 4 cm (2 in) to the left of the hazard warning switch breakout

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S213

In the IP harness, approximately 9 cm (4 in) to the left of the hazard warning switch breakout

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S214

In the IP harness, approximately 25 cm (10 in) to the right of the data link connector (DLC) breakout

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S219

In the IP harness, approximately 17 cm (7 in) to the right of the data link connector (DLC) breakout

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S220

In the IP harness, approximately 15 cm (6 in) to the right of the data link connector (DLC) breakout

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S221

In the IP harness, approximately 12 cm (5 in) to the right of the data link connector (DLC) breakout

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S225 (Cat® Diesel)

In the IP harness, at the anode (+) end of the charge indicator diode (D200), approximately 4 cm (2 in) to the right of the data link connector (DLC) breakout

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S226 (Cat® Diesel)

In the IP harness, at the cathode (-) end of the charge indicator diode (D200), approximately 10 cm (4 in) to the right of the data link connector (DLC) breakout

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S227

In the IP harness, approximately 57 cm (22 in) from the headlamps dimmer switch breakout

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S230

In the IP harness, approximately 4 cm (2 in) to the right of the instrument panel cluster (IPC) connector breakout

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S231

In the IP harness, approximately 66 cm (26 in) from the main harness, toward the IP harness connector

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S232

In the IP harness, approximately 59 cm (23 in) from the main harness, toward the IP harness connector

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S234

In the IP harness, approximately 4 cm (2 in) to the right of the daytime running lights (DRL) module breakout

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S235 (ABS-Hydraulic)

In the IP harness, at the cathode (-) end of the ABS diode (D201), approximately 4 cm (2 in) from the MaxiFuse® block/ mini-relay center, toward the bulkhead

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S258

In the IP harness, approximately 9 cm (4 in) to the right of the hazard warning switch breakout

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S261 (ABS-Hydraulic)

In the ABS-hydraulic jumper harness, approximately 40 cm (16 in) from the exterior bulkhead pass-through P103

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S262 (ABS-Hydraulic)

In the ABS-hydraulic jumper harness, approximately 46 cm (18 in) from the exterior bulkhead pass-through P103

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S405

In the fuel tank harness, approximately 196 cm (77 in) to the rear of the fuel harness connector

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