Chevrolet TrailBlazer 2003 - 2003 GENERAL MOTORS Bravada, Envoy, Envoy XL, TrailBlazer, TrailBlazer XL

Chevrolet TrailBlazer 2003 - BUZZERS, RELAYS & TIMERS

Chevrolet TrailBlazer 2003 BUZZERS, RELAYS & TIMERS LOCATION

Component	Location
A/C Relay	On underhood fuse block.
Cooling Fan Relay	On underhood fuse block.
Foglamp Relay	On underhood fuse block.
Fuel Pump Relay	On underhood fuse block.
Headlamp Driver Module	On underhood fuse block.
Headlamp Hi-Beam Relay	On underhood fuse block.
Headlamp Washer Relay	On underhood fuse block.
Horn Relay	On underhood fuse block.
Lock Relay	On rear fuse block.
Park Lamp Relay	On rear fuse block.
Rear Foglamp Relay	On rear fuse block.
Rear Window Washer Relay	On underhood fuse block.
Starter Relay	On underhood fuse block.
Unlock Relay	On rear fuse block.
Windshield Washer Relay	On underhood fuse block.

Chevrolet TrailBlazer 2003 - CIRCUIT PROTECTION DEVICES

Chevrolet TrailBlazer 2003 CIRCUIT PROTECTION DEVICES LOCATION

Component	Location
Doors Circuit Breaker (Left)	On rear fuse block.
Doors Circuit Breaker (Right)	On rear fuse block.
Rear Fuse Block	Below left rear seat. See Fig. 7.
Seats Circuit Breaker	On rear fuse block.
Underhood Fuse Block	On left side of engine compartment.

Chevrolet TrailBlazer 2003 - CONTROL UNITS

Chevrolet TrailBlazer 2003 CONTROL UNITS LOCATION

Component	Location
Auxiliary Blower Motor Processor	In rear HVAC module, behind right rear interior panel.
Body Control Module (BCM)	Beneath left rear seat, on rear fuse block. See Fig. 7.
Driver Door Module	Below driver's door switch panel.
Electronic Brake Control Module	On inner left frame rail, beside transmission.
Front Passenger Door Module	Below front passenger door switch panel.
Headlamp Driver Module	On underhood fuse block.
Ignition Coil/Module (6)	On top of valve cover, above respective cylinder.
Inflatable Restraint Sensing & Diagnostic Module	Below rear of center console.
Inflatable Restraint Side Impact Sensing Module (Left)	In left front seat back.
Inflatable Restraint Side Impact Sensing Module (Right)	In right front seat back.
Memory Seat Module	Below left front seat.
Powertrain Control Module (PCM) (4.2L)	On upper left side of engine. See Fig. 3.
Powertrain Control Module (PCM) (5.3L)	Near lower left front of engine.
Sun Roof Module	Above headliner, at rear of sun roof assembly. See Fig. 11.
Transfer Case Shift Control Module	Behind lower left side of dash. See Fig. 6.
Turn Signal/Hazard Flasher Module	Behind lower left side of dash.
Vehicle Communication Interface Module	Under right rear seat.

Chevrolet TrailBlazer 2003 - MOTORS

Chevrolet TrailBlazer 2003 MOTORS LOCATION

Component	Location
Air Suspension Compressor Assembly (Except XL)	Behind right rear wheelwell, on frame rail. See Fig. 9.
Air Suspension Compressor Assembly (XL)	On left rear frame rail, near spare tire. See Fig. 10.
Air Temperature Actuator (Left)	Behind left center of dash. See Fig. 5.
Air Temperature Actuator (Right)	Behind right center of dash.
Blower Motor	Below right side of dash.
Blower Motor (Auxiliary) (Except XL)	Below center of dash.
Blower Motor (Auxiliary) (XL)	On right side of cargo area, behind trim panel.
Defrost Actuator	Behind upper left center of dash. See Fig. 5.
Front Axle Actuator	On inner flange of right front axle.
Fuel Pump & Sender Assembly	Inside fuel tank.
Headlamp Leveling Actuator (Left)	Behind left headlamp.
Headlamp Leveling Actuator (Right)	Behind right headlamp.
Mode Actuator	Behind upper left center of dash. See Fig. 5.
Mode Actuator (Auxiliary)	Below center of dash.
Recirculation Actuator	Behind upper right side of dash.
Sun Roof Motor	Above headliner, at rear of sun roof assembly.
Throttle Actuator Control (TAC) Motor (4.2L)	On throttle body. See Fig. 1.
Throttle Actuator Control (TAC) Motor (5.3L)	On throttle body.
Window Washer Pump (Rear)	On washer fluid reservoir.
Window Wiper Motor (Rear)	Inside tailgate.
Windshield Washer Fluid Pump	On washer fluid reservoir.
Windshield Wiper Motor	On upper center of firewall.

Chevrolet TrailBlazer 2003 - SENDING UNITS & SENSORS

Chevrolet TrailBlazer 2003 SENDING UNITS & SENSORS LOCATION

Component	Location
A/C Refrigerant Pressure Sensor	On high pressure line, near A/C compressor.
Accelerator Pedal Position Sensor	Above accelerator pedal, on bracket.
Air Suspension Sensor (Left)	On frame rail, near left rear suspension arm.
Air Suspension Sensor (Right)	On frame rail, near right rear suspension arm. See Fig. 8.
Ambient Air Temperature Sensor	On left center of radiator support.
Ambient Light Sensor	On top center of dash.
Ambient Light/Sun Load Sensor	On top center of dash, near base of windshield.
Camshaft Position (CMP) Sensor (4.2L)	On right front of cylinder head. See Fig. 2.
Camshaft Position (CMP) Sensor (5.3L)	On top rear of engine block, near transmission.
Crankshaft Position (CKP) Sensor (4.2L)	On left rear of engine block, below starter. See Fig. 4.
Crankshaft Position (CKP) Sensor (5.3L)	At right rear of engine, adjacent to starter.
Engine Coolant Temperature (ECT) Sensor	On left front of engine block, near generator. See Fig. 3.
Fuel Pump & Sender Assembly	Inside fuel tank.
Fuel Tank Pressure Sensor	At top left rear of fuel tank.
Heated Oxygen Sensor Bank No. 1 Sensor No. 1 (5.3L)	In left bank exhaust pipe, ahead of catalytic converter.
Heated Oxygen Sensor Bank No. 1 Sensor No. 2 (5.3L)	In left bank of exhaust pipe, behind catalytic converter.
Heated Oxygen Sensor Bank No. 2 Sensor No. 1 (5.3L)	In right bank of exhaust pipe, ahead of catalytic converter.
Heated Oxygen Sensor Bank No. 2 Sensor No. 2 (5.3L)	In right bank of exhaust pipe, behind catalytic converter.
Heated Oxygen Sensor No. 1 (4.2L)	On exhaust manifold, on right side of engine.
Heated Oxygen Sensor No. 2 (4.2L)	Downstream of catalytic converter, on exhaust pipe.
Inflatable Restraint Front End Discriminating Sensor (Left)	At left rear of front frame crossmember.
Inflatable Restraint Front End Discriminating Sensor (Right)	At right rear of front frame crossmember.
Inside Air Temperature Sensor Assembly	At top of left "B" pillar, behind trim.
Intake Air Temperature (IAT) Sensor	In air intake duct, on top right of engine. See Fig. 1.
Knock Sensor No. 1 (4.2L)	On lower left front of engine block. See Fig. 4.
Knock Sensor No. 2 (4.2L)	On lower left rear of engine block. See Fig. 4.
Knock Sensor (5.3L)	On top rear of engine.
Lower Left Air Temperature Sensor	Behind lower left center of dash, on air duct.
Lower Right Air Temperature Sensor	Behind lower right side of dash, on air duct.
Manifold Absolute Pressure (MAP) Sensor (4.2L)	On upper left side of engine. See Fig. 1.
Manifold Absolute Pressure (MAP) Sensor (5.3L)	On top of engine.
Mass Airfow/Intake Air Temperature Sensor	In air intake duct.
Passlock Sensor	In ignition lock cylinder case.
Propshaft Speed Sensor (Left Front)	On left front of transfer case.
Propshaft Speed Sensor (Right Rear)	On right rear of transfer case.
Rain Sensor	On upper center of windshield.
Upper Left Air Temperature Sensor	Behind upper left center of dash.
Upper Right Air Temperature Sensor	Behind upper right center of dash.
Vehicle Speed Sensor	On left rear of transfer case.
Wheel Speed Sensor (Left Front)	On left front spindle/hub assembly.
Wheel Speed Sensor (Right Front)	On right front spindle/hub assembly.

Chevrolet TrailBlazer 2003 - SOLENOIDS & SOLENOID VALVES

Chevrolet TrailBlazer 2003 SOLENOIDS & SOLENOID VALVES LOCATION

Component	Location
Camshaft Actuator Solenoid Assembly	On right front of cylinder head. See Fig. 2.
Evaporative Emission (EVAP) Canister Purge Solenoid	On left side of engine block. See Fig. 4.
Evaporative Emission (EVAP) Canister Vent Solenoid	At rear of fuel tank.
Ignition Lock Solenoid	Inside steering column.

Chevrolet TrailBlazer 2003 - SWITCHES

Chevrolet TrailBlazer 2003 SWITCHES LOCATION

Component	Location
A/C Low Pressure Switch	At right rear of engine compartment, on accumulator.
Air Suspension Inflator Switch (Except XL)	On right side of cargo area, on trim panel.
Air Suspension Inflator Switch (XL)	On left side of cargo area, on trim panel.
Back-Up Lamp Switch	Integral with park/neutral position switch.
Brake Fluid Level Switch	On brake master cylinder fluid reservoir.
Hood Ajar Switch	On top left of radiator support.
Ignition Key Alarm Switch	In steering column.
Oil Pressure Switch (4.2L)	On right side of engine block.
Oil Pressure Switch (5.3L)	At top rear of engine block, near transmission.
Park Brake Switch	On parking brake assembly.
Park/Neutral Position Switch	On lower left side of transmission.
Park Switch	On shift lever assembly.
Seat Belt Switch (Left Front)	In left front seat belt buckle.
TCC/Brake Switch	Above brake pedal, on bracket.
Windshield Washer Fluid Level Switch	In windshield washer fluid reservoir.

Chevrolet TrailBlazer 2003 - MISCELLANEOUS

Chevrolet TrailBlazer 2003 MISCELLANEOUS LOCATION

Component	Location
Audio Amplifier (Except XL)	On right side of cargo area, behind trim panel.
Audio Amplifier (XL)	On left side of cargo area, behind trim panel.
Blower Motor Resistor Assembly	Below right side of dash, near blower motor.
Data Link Connector	On bottom left side of dash.
Ignition Coil/Module (6)	On top of valve cover, above respective cylinder.
Star Connector No. 1	On lower left side of dash.
Star Connector No. 2	In body harness, below right rear seat.
Travel Note Recorder	Inside roof console.

Chevrolet TrailBlazer 2003 - CONNECTORS

Chevrolet TrailBlazer 2003 CONNECTORS LOCATION

Component	Location
C100 (Black, 10 Pin)	I/P harness to engine harness, in underhood compartment, to left of engine.
C101 (Black, 38 Pin)	I/P harness to chassis harness, in underhood compartment, to right of underhood fuse block.
C104 (Black, 8 Pin)	At rear of engine, near coil No. 6.
C105 (Black, 10 Pin)	Forward lamp harness to I/P harness, underhood compartment, near underhood fuse block.
C108 (Black, 8 Pin)	In coils harness to engine harness, on top of right bank valve cover.
C109 (Black, 8 Pin)	In coils harness to engine harness, on top of left bank valve cover.
C118	On upper left of fan shroud.
C175 (20 Pin)	Engine harness to automatic transmission harness, on right side of transmission.
C201 (Black/Gray, 48 Pin)	Steering column harness to I/P harness, lower part of steering column.
C202 (Natural)	I/P harness to headliner harness, lower right side of dash.
C203 (Yellow, 4 Pin)	I/P harness to body connector, lower right side of dash.
C301 (Black, 8 Pin)	I/P harness to body harness, under carpet, rear floor area.
C303 (6 Pin)	I/P harness to body harness, under carpet, rear floor area.
C304 (Black, 16 Pin)	I/P harness to body harness, under carpet, rear floor area.
C305 (Black, 16 Pin)	Overhead console harness to headliner harness, inside upper console.
C306 (Black, 6 Pin)	Body harness to headliner harness, under carpet, at rear floor area.
C307 (Gray, 18 Pin)	Beneath lower console.
C308 (Black, 6 Pin)	Headliner harness to sun roof harness, above left rear door.
C309 (Black, 10 Pin)	Console harness to body harness, under lower rear console, near C307.
C310 (Black, 2 Pin)	Chassis harness to engine harness, near transfer case.
C311 (Black, 10 Pin)	Body harness to seat harness, lower front of driver's seat.
C312 (Black, 16 Pin)	Seat harness to seat back harness, under driver's seat.
C313 (Black, 6 Pin)	Seat harness to seat motor harness, under driver's seat.
C314 (Black, 10 Pin)	Body harness to seat harness, lower front of passenger seat.
C315 (Black, 16 Pin)	Seat harness to seat back harness, under passenger seat.
C316 (Gray, 8 Pin)	Under passenger seat, main seat harness to seat motors.
C401 (12 Pin)	Body harness to rear HVAC module harness, behind right rear body side panel.
C500 (Black, 12 Pin)	Body harness to left front door harness, at midpoint of leading edge of door.
C600 (Black, 12 Pin)	Body harness to right front door harness, at midpoint of leading edge of door.
C700 (Black/Natural, 17 Pin)	Body harness to left rear door harness, at midpoint of leading edge of door.
C800 (Black/Natural, 17 Pin)	Body harness to right rear door harness, at midpoint of leading edge of door.
C900 (Black, 6 Pin)	Body harness to liftgate harness, at top of liftgate.
C901 (Gray, 2 Pin)	Liftgate harness to license lamp harness, inside liftgate.

Chevrolet TrailBlazer 2003 - GROUNDS

Chevrolet TrailBlazer 2003 GROUNDS LOCATION

Component	Location
G101	Left side of underhood compartment, near front of underhood fuse block.
G102	Left side of underhood compartment, near rear of underhood fuse block.
G103	Left front of underhood compartment, on left side of radiator support.
G104	On underside of hood, near underhood compartment lamp.
G105	In underhood compartment, on firewall, near I/P harness pass-through.
G106	On engine side of left front wheelwell.
G107	On lower left side of engine.
G108	On lower left side of engine.
G109	On lower left side of engine.
G110	On lower left side of engine.
G201	Ground splice pack near, right front of lower console.
G301	Floor in tunnel/console area.
G302	On lower left "B" pillar.
G303	On lower right "B" pillar.
G304	On outside of left frame rail, near electronic brake control module.
G305	On outside of left frame rail, near fuel tank.
G306	On body panel, rear of left rear door.
G401	On lower left "D" pillar.
G402	On lower right "D" pillar.
G403	On left side of rear frame crossmember.

Chevrolet TrailBlazer 2003 - SPLICES

Chevrolet TrailBlazer 2003 SPLICES LOCATION

Component	Location
SP201	At lower right front of lower console.
SP205	Behind left of dash, near headlamp switch connector.
SP306	In body harness, under right rear seat.
S103	Forward lamp harness, 8 cm from rear washer pump motor breakout, toward right turn signal breakout.
S105	I/P harness, 4.5 cm from C105 breakout, toward wiper motor breakout.
S107	Forward lamp harness, 4.5 cm from left turn signal breakout, toward left headlamp breakout.
S113	Forward lamp harness, 20 cm from windshield washer pump breakout, toward engine cooling fan breakout.
S117	I/P harness, 8.5 cm from C100 breakout, toward underhood fuse block C5 & C6 breakouts.
S202	I/P harness, 16.5 cm from steering column connector breakout, toward DLC breakout.
S211	I/P harness, 16 cm from SP201 breakout, toward DLC.
S216	I/P harness, 15.5 cm from recirculation actuator connector.
S217	I/P harness, 5 cm from mode motor breakout, toward instrument cluster breakout.
S226	Ground circuit splice in steering column.
S230	I/P harness, 5 cm from SP201 breakout, toward I/P auxiliary power breakout.
S232	I/P harness, 10 cm from steering column breakout, toward headlamp switch breakout.
S239	I/P harness, above dash left lower panel, 11 cm from steering column breakout, toward data link connector breakout.
S271	I/P harness, 14.5 cm from dash compartment lamp breakout, toward center of dash.
S302	5 cm from main harness breakout for C700, toward G302.
S303	5 cm from main harness breakout for C800, toward G303.
S307	Console harness.
S310	Under driver's seat.
S311	Under driver's seat, 4.5 cm from lumbar switch breakout, toward body connector.
S312	In main headliner harness, 80 cm from C308 breakout, toward front courtesy/reading lamp.
S313	Driver's seat motor harness, 17 cm from seat module connector C2.
S314	Driver's seat motor harness, 24 cm from seat module connector C2.
S317	Under passenger seat, 4.5 cm from lumbar switch breakout, toward body connector.
S318	Driver's seat main harness, 7 cm from body connector breakout, toward seat back connector.
S319	Passenger seat main harness, 7 cm from body connector breakout, toward seat back connector.
S320	I/P harness, 18 cm from automatic transmission shift lever connector breakout, toward DLC.
S322	Headliner harness, 16 cm from ISRVM breakout, toward right sun shade mirror lamp.
S324	In lower console harness, between auxiliary HVAC module & C309.
S325	In lower console harness, between auxiliary HVAC module & C309.
S326	In lower console harness, between auxiliary HVAC module & C309.
S329	Headliner harness, 25 cm from left sun shade mirror lamp breakout, toward C305.
S330	Overhead console harness.
S331	Headliner harness, 17 cm from left sun shade mirror lamp breakout, toward C305.
S332	Overhead console harness.
S333	In headliner harness, 13 cm from cargo lamp breakout, toward left quarterglass breakout.
S340	Overhead console harness.
S346 (Long Wheelbase)	Body harness, 5 cm from breakout for left front seat, toward C500.
S346 (Short Wheelbase)	Body harness, 15 cm from breakout for left front seat, toward C500.
S347 (Long Wheelbase)	Body harness, 5 cm from breakout for right front seat, toward C600.
S347 (Short Wheelbase)	Body harness, 15 cm from breakout for right front seat, toward C600.
S350	In headliner harness, 3.5 cm from left quarterglass breakout, toward left rear courtesy lamp breakout.
S390	Headliner harness, 26 cm from left front dome/reading lamp, toward left sun shade mirror lamp.
S391	In headliner harness, 6.5 cm from left quarterglass breakout, toward cargo lamp breakout.
S401 (Long Wheelbase)	Body harness, 13 cm from G402 breakout, toward front of vehicle.
S401 (Short Wheelbase)	Body harness, 7.5 cm from G402 breakout, toward front of vehicle.
S900	Main liftgate harness, 50 cm from liftgate module breakout, toward C900.
S902	License lamp harness.
S909	License lamp harness.