GM Service Manual Online
For 1990-2009 cars only

Name

Location

Locator View

Connector End View

Accelerator Pedal (AP) (Gasoline)

To the left of center, on the lower bulkhead

Engine Controls Component Views

Engine Controls Connector End Views

Automatic Transmission (AT) Modulator (Cat® Diesel)

On the lower left side of the transmission

Engine Controls Component Views

Engine Controls Connector End Views

Automatic Transmission (AT) Modulator (Gasoline)

On the lower left side of the transmission

Engine Controls Component Views

Engine Controls Connector End Views

Brake Switch Interface Module

In the center of the IP mounted on the shelf

Engine Controls Component Views

Engine Controls Connector End Views

Camshaft Position Sensor

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

Engine Controls Component Views

Engine Controls Connector End Views

Canister Purge Solenoid

On the left side of the intake plenum

Engine Controls Component Views

Engine Controls Connector End Views

Clutch/  Starter Interlock Switch (Cat® Diesel)

On the clutch pedal bracket

Engine Electrical Component Views in Engine Electrical

Engine Electrical Connector End Views in Engine Electrical

Clutch/  Starter Interlock Switch (Gasoline)

On the clutch pedal bracket

Engine Electrical Component Views in Engine Electrical

Engine Electrical Connector End Views in Engine Electrical

Clutch/ Starter Interlock Switch Jumper Harness (C215, 2 cavities) (Automatic Transmission) (Cat® Diesel)

On the clutch switch jumper, to the IP harness, at the clutch pedal support bracket

Engine Electrical Component Views in Engine Electrical

Engine Electrical Connector End Views in Engine Electrical

Clutch/ Starter Interlock Switch Jumper Harness (C215, 2 cavities) (Automatic Transmission) (Gasoline)

On the clutch switch jumper, to the IP harness, at the clutch pedal support bracket

Engine Electrical Component Views in Engine Electrical

Engine Electrical Connector End Views in Engine Electrical

Crankshaft Position (CKP) Sensor (Gasoline)

At the bottom of the front timing cover

Engine Controls Component Views

Engine Controls Connector End Views

Cruise Control Clutch Switch

Under the IP on the left side of the steering column

Engine Controls Component Views

Engine Controls Connector End Views

Cruise Control Switch

On the left side of the steering column

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

Engine Controls Connector End Views

Cruise Control Switch

On the left side of the steering column

Cruise Control Component Views in Cruise Control

Cruise Control Connector End Views in Cruise Control

Data Link Connector (DLC) (Cat® Diesel)

Under the left side of the IP

Data Link Communications Component Views in Wiring Systems

Power and Grounding Connector End Views

Data Link Connector (DLC) (Cat® Diesel)

Under the left side of the IP

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

Engine Controls Connector End Views

Data Link Connector (DLC) (Gasoline)

Under the left side of the IP

Data Link Communications Component Views in Wiring Systems

Power and Grounding Connector End Views

Data Link Connector (DLC) (Gasoline)

Under the left side of the IP

Engine Controls Component Views

Engine Controls Connector End Views

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 in Instrument Panel, Gauges and Console

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 in Instrument Panel, Gauges and Console

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 in Instrument Panel, Gauges and Console

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 in Instrument Panel, Gauges and Console

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 in Instrument Panel, Gauges and Console

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 in Instrument Panel, Gauges and Console

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 in Instrument Panel, Gauges and Console

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 in Instrument Panel, Gauges and Console

Instrument Panel, Gages, and Console Connector End Views

Electronic Throttle Actuator Control Module - C1

In the center of the IP mounted on the shelf

Engine Controls Component Views

Engine Controls Connector End Views

Electronic Throttle Actuator Control Module - C2

In the center of the IP mounted on the shelf

Engine Controls Component Views

Engine Controls Connector End Views

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 in Instrument Panel, Gauges and Console

Instrument Panel, Gages, and Console Connector End Views in Instrument Panel, Gauges and Console

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 in Instrument Panel, Gauges and Console

Instrument Panel, Gages, and Console Connector End Views in Instrument Panel, Gauges and Console

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 in Instrument Panel, Gauges and Console

Instrument Panel, Gages, and Console Connector End Views in Instrument Panel, Gauges and Console

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

Engine Controls Connector End Views

Exhaust Gas Recirculation Valve (EGR

On the left side of the intake plenum

Engine Controls Component Views

Engine Controls Connector End Views

Fuel Injectors (Gasoline)

Under the intake plenum, in the intake manifold

Engine Controls Component Views

Engine Exhaust Brake Connector End Views

Fuel Pump Prime (Gasoline)

In the center of the IP, under the hazard switch

Engine Controls Component Views

Engine Controls Connector End Views

Fuel Sender and Fuel Pump (FP) (Gasoline)

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

Engine Controls Component Views

Engine Controls Connector End Views

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

Fuel Sender, Left (Cat® Diesel)

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

Fuel Sender, Right (Cat® Diesel)

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

Instrument Panel, Gages, and Console Component Views

Instrument Panel, Gages, and Console Connector End Views

Fuse/Relay Center

On the right side of the dash

--

--

HI IDLE Switch (Cat® Diesel)

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

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

Engine Controls Connector End Views

HI IDLE Switch (Gasoline)

On the center of the IP

Engine Controls Component Views

Engine Controls 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

Ignition Coils

On the left and right side valve covers

Engine Controls Component Views

Engine Controls Connector End Views

Instrument Panel Cluster (IPC)

In the left side of the IP

Instrument Panel, Gages, and Console Component Views in Instrument Panel, Gauges and Console

Instrument Panel, Gages, and Console Connector End Views

Intake Air Temperature (IAT) Sensor (Gasoline)

In the air duct, between the air filter housing and the throttle body, on the right side of the engine

Engine Controls Component Views

Engine Controls Connector End Views

Knock Sensor (KS) Bank 1

In the engine block, left side below the exhaust manifold

Engine Controls Component Views

Engine Controls Connector End Views

Knock Sensor (KS) Bank 2

In the engine block, right side below the exhaust manifold

Engine Controls Component Views

Engine Controls Connector End Views

Manifold Absolute Pressure (MAP) Sensor

In the front center of the intake manifold, behind the water outlet

Engine Controls Component Views

Engine Controls Connector End Views

Mass Air Flow Sensor

In the air duct, between the air filter housing and the throttle body, on the right side of the engine

Engine Controls Component Views

Engine Controls 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

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

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

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

Multifunction Alarm Module (MFAM) (Gasoline)

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

Engine Controls Component Views

Engine Controls Connector End Views

Multifunction Alarm Module (MFAM) Jumper (Shunt) (Cat® Diesel w/ out Automatic Engine Shutdown)

In the IP harness, taped to the main harness, between the IP fuse block and MFAM breakouts.

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

Engine Controls Connector End Views

Neutral Switch (Automatic Transmission)

On the lower right side of the transmission

Engine Electrical Component Views in Engine Electrical

Engine Electrical Connector End Views

Oxygen Sensor (O2S) LH Pre-Convertor

On the left exhaust pipe, below the exhaust manifold

Engine Controls Component Views

Engine Controls Connector End Views

Oxygen Sensor (O2S) RH Pre-Convertor

On the right exhaust pipe, below the exhaust manifold

Engine Controls Component Views

Engine Controls 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

--

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

Under the left front cowel in front of driver

Engine Controls Component Views

Engine Controls Connector End Views

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

Under the left front cowel in front of driver

Engine Controls Component Views

Engine Controls Connector End Views

Speedo Adapter

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

Instrument Panel, Gages, and Console Component Views in Instrument Panel, Gauges and Console

Engine Electrical Connector End Views in Engine Electrical

Speedometer

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

Instrument Panel, Gages, and Console Component Views in Instrument Panel, Gauges and Console

Instrument Panel, Gages, and Console Connector End Views in Instrument Panel, Gauges and Console

Throttle Position (TP) Sensor

On the front side of the throttle body

Engine Controls Component Views

Engine Controls Connector End Views

Throttle Stepper Motor

On the back side of the throttle body

Engine Controls Component Views

Engine Controls Connector End Views

Vehicle Speed Sensor (VSS) (Gasoline)

On the lower right side of the transmission tailshaft housing

Instrument Panel, Gages, and Console Component Views in Instrument Panel, Gauges and Console

Engine Controls Connector End Views

Vehicle Speed Sensor (VSS) (Gasoline)

On the lower right side of the transmission tailshaft housing

Engine Controls Component Views

Engine Controls Connector End Views

Vehicle Speed Sensor (VSS) (Cat® Diesel)

On the lower right side of the transmission tailshaft housing

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

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

C109 (8 cavities) (gasoline)

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

--

Inline Harness Connector End Views in Wiring Systems

C110 (10 cavities) (gasoline)

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

--

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

--

Inline Harness Connector End Views in Wiring Systems

C116 (5 cavities) (Gasoline)

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

--

Inline Harness Connector End Views in Wiring Systems

C118 (3 cavities)

Engine harness to the crankshaft position sensor harness

--

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

--

Inline Harness Connector End Views in Wiring Systems

C127

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

--

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

--

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

--

Inline Harness Connector End Views in Wiring Systems

C210

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

--

Inline Harness Connector End Views in Wiring Systems

C212 (23 cavities) (Upfitter Connector)

Under the left side of the IP, by the left kick panel

--

Inline Harness Connector End Views in Wiring Systems

C215 (2 cavities) (Automatic Transmission)

In the IP harness, to the clutch/ starter interlock switch jumper, near the brake pedal

--

Inline Harness Connector End Views in Wiring Systems

C408

In the engine harness, to the transmission harness, on the left side of the engine, at the bellhousing

--

Inline Harness Connector End Views in Wiring Systems

C409 (8 cavities) (Cat® Diesel)

In the engine harness, to the transmission harness, on the left side of the engine, at the bellhousing

--

Inline Harness Connector End Views in Wiring Systems

C409 (8 cavities) (Gasoline)

In the engine harness, to the transmission harness, on the left side of the engine, at the bellhousing

--

Inline Harness Connector End Views in Wiring Systems

C415

In the engine harness, to the transmission harness, on the left side of the engine, at the bellhousing

--

Inline Harness Connector End Views in Wiring Systems

G106 (Gasoline)

From the engine harness to the left rear side of the left cylinder head

--

--

P100

On the right side of the bulkhead

--

--

P102

On the right side of the bulkhead

--

--

S138

In the engine harness, approximately 4 cm (1.6 in) from the generator harness breakout

--

--

S138 (Cat® Diesel)

In the engine harness, approximately 11 cm (4.3 in) from the main harness, toward the forward lamps harness connector

--

--

S141

In the engine harness, approximately 17 cm (6.7 in) throttle position (TP), from generator harness breakout

--

--

S142 (Gasoline)

In the engine harness, approximately 4 cm (1.6 in) from the throttle position (TP) sensor, toward the breakout

--

--

S142 (Cat® Diesel)

In the engine harness, approximately 4 cm (1.6 in)

--

--

S176

In the engine harness, approximately 19.5 cm (7.7 in) from the injector harness connector breakout towards powertrain control module (PCM)

--

--

S177

In the engine harness, approximately 26 cm (10.2 in) from the injector harness connector breakout towards powertrain control module (PCM)

--

--

S178

In the right bank ignition coil harness, approximately 18 cm (7 in) from the C110 connector

--

--

S179

In the left bank ignition coil harness, approximately 15 cm (6 in) from the C109 connector

--

--

S180

In the right bank ignition coil harness, approximately 10 cm (4 in) to the rear of the #4 coil breakout

--

--

S181

In the left bank ignition coil harness, approximately 36 cm (14 in) from the C109 connector

--

--

S184

In the engine harness, approximately 12.5 cm (4.9 in) from the breakout in the line for the mass air flow sensor

--

--

S185

In the engine harness, approximately 12.5 cm (4.9 in) from the breakout in the line for the starter solenoid wires

--

--

S186

In the engine harness, approximately 6.5 cm (2.5 in) from the P102 breakout toward the P100

--

--

S187

In the fuel injector harness, approximately 8 cm (3 in) from the #5 injector breakout, toward the #3 injector

--

--

S188

In the fuel injector harness, approximately 7 cm (2.5 in) from the #6 injector breakout, toward the #4 injector

--

--

S210

In the IP harness, approximately 4 cm (1.6 in) to the right of the hazard warning switch breakout

--

--

S219

In the IP harness, approximately 17 cm (6.7 in) to the right of the data link connector (DLC) breakout

--

--

S220

In the IP harness, approximately 15 cm (5.9 in) to the right of the data link connector (DLC) breakout

--

--

S221

In the IP harness, approximately 12 cm (4.7 in) to the right of the data link connector (DLC) breakout

--

--

S230

In the IP harness, approximately 4 cm (1.6 in) to the right of the instrument panel cluster (IPC) connector breakout

--

--

S232

In the IP harness, approximately 59 cm (23.2 in) from the main harness, toward the IP harness connector

--

--