Chevrolet TrailBlazer (2002-2009) fuse box and relay Diagrams
The Chevrolet TrailBlazer, produced from 2002 to 2009, is a midsize SUV known for its robust performance, versatile capabilities, and comfortable ride. Designed to accommodate both urban commuting and off-road adventures, the TrailBlazer’s electrical system is integral to its functionality. The fuse box and relays are crucial components that help manage and protect the vehicle’s complex array of electrical systems.
The fuse box in the Chevrolet TrailBlazer is vital for safeguarding the vehicle’s electrical circuits. These circuits power essential systems such as the engine management, lighting, climate control, infotainment, and power accessories, including windows and door locks. Typically, the TrailBlazer is equipped with two main fuse boxes: one in the engine compartment and another inside the cabin, usually located under the dashboard on the driver’s side. The engine compartment fuse box manages high-power systems related to the engine and transmission, while the interior fuse box handles many of the vehicle’s comfort and convenience features.
Each fuse is associated with a specific circuit and is designed to “blow” or break the circuit if there’s an overload or short circuit. This action prevents damage to more sensitive components, avoiding potential electrical fires and expensive repairs. If a system, such as the headlights or power windows, stops functioning, inspecting the related fuse is often the first troubleshooting step.
Relays are electrically operated switches that control the power supply to high-current systems such as the starter motor, fuel pump, and cooling fans. Relays enable these systems to be managed by lower-power control circuits, ensuring that the vehicle’s wiring and switches are not overloaded and operate safely. This setup enhances both the reliability and efficiency of the TrailBlazer’s electrical systems.
Regular maintenance of the fuse box and relays is crucial for preventing electrical issues in the TrailBlazer. A blown fuse or faulty relay can result in system malfunctions, such as the engine not starting if the starter relay is compromised, or overheating issues if the cooling fan relay fails. Replacing these components with the correct specifications is essential to restoring the vehicle’s functionality.
By understanding the roles of the fuse box and relays, owners can better maintain their Chevrolet TrailBlazer’s electrical system, ensuring all features operate reliably and safely. This attention to maintenance helps preserve the SUV’s performance and dependability, making it a trusted vehicle for both everyday commutes and adventurous trips.
MUST READ: DYI – How to Check Car Fuses?
(2002-2009) Chevrolet TrailBlazer fuse box and relay with Diagram
WARNING
- Never replace a fuse with one that has a higher amperage rating.
- A fuse with a too-high amperage could damage the electrical part and cause a fire.
- On no account should fuses be repaired (e.g. patched up with tin foil or wire) as this may cause serious damage elsewhere in the electrical circuit or cause a fire.
- If a fuse blows repeatedly, do not keep replacing it. Instead, have the cause for the repeated short circuit or overload tracked and fixed.
- Terminal and harness assignments for individual connectors will vary depending on vehicle equipment level, model, and market.
Chevrolet TrailBlazer 2002-2009 fuse assignment
- Cigar lighter (power outlet) fuses in the Chevrolet TrailBlazer is the fuse №. 13 (Cigarette Lighter) in the Underhood Fuse Box and fuses №. 15 (2002-2003, Auxiliary Power 2), №. 46 (Auxiliary Power 1) in the Rear Underseat Fuse Box.
Year of production: from 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
Engine Compartment Fuse Box
Fuse box location
It is located in the engine compartment on the driver’s side, under two covers.
Fuse box diagrams (L6 Engine)
L6 engine, 2002-2003
Assignment of the fuses and relay in the Underhood Fuse Box, L6 engine (2002, 2003)
| № | Usage |
|---|---|
| 1 | Electrically-Controlled Air Suspension |
| 2 | Passenger’s Side Hiqh-Beam Headlamp |
| 3 | Passenger’s Side Low-Beam Headlamp |
| 4 | Back-Up-Trailer Lamps |
| 5 | Driver’s Side High-Beam Headlamp |
| 6 | Driver s Side Low-Beam Headlamp |
| 7 | WASH |
| 8 | Automatic Transfer Case |
| g | Windshield Wipers |
| 10 | Powertrain Control Module B |
| 11 | Fog Lamps |
| 12 | Stop Lamp |
| 13 | Cigarette Lighter |
| 14 | Ignition Coils |
| 15 | Air Suspension Ride |
| 16 | TBD-Ignition 1 |
| 17 | Crank |
| 18 | Air Bag |
| 19 | Electric Brake |
| 20 | Cooling Fan |
| 21 | Horn |
| 22 | Ignition E |
| 23 | Electronic Throttle Control |
| 24 | Instrument Panel Cluster, Dnver Information Center |
| 25 | Automatic Shift Lock Control System |
| 26 | Engine 1 |
| 27 | Back-Up |
| 28 | Powertrain ControJ Module 1 |
| 29 | Oxygen Sensor |
| 30 | Air Conditioning |
| 31 | Truck Body Controller |
| 32 | Trailer |
| 33 | Anti-Lock Brakes (ABS) |
| 34 | Ignition A |
| 35 | Blower Motor |
| 36 | Ignition B |
| 50 | Passenger s Side Trailer Turn |
| 51 | Driver s Side Trailer Turn |
| 52 | Hazard Flashers |
| Relays | |
| 37 | Blank |
| 38 | Rear Window Washer |
| 39 | Fog Lamps |
| 40 | Horn |
| 41 | Fuel Pump |
| 42 | Windshield Wipers/Washer |
| 43 | High-Beam Headlamp |
| 44 | Air Conditioning |
| 45 | Cooling Fan |
| 46 | Headlamp Driver Modulo |
| 47 | Starter |
| Miscellaneous | |
| 48 | Instrument Panel Battery |
| 49 | Fuse Puller |
L6 engine, 2004-2006
Assignment of the fuses and relay in the Underhood Fuse Box, L6 engine (2004, 2005, 2006)
| № | Usage |
|---|---|
| 1 | Electrically-Controlled Air-suspension |
| 2 | Passenger’s Side High-Beam Headlamp |
| 3 | Passenger’s Side Low-Beam Headlamp |
| 4 | Back-Up Trailer Lamps |
| 5 | Driver’s Side High-Beam Headlamp |
| 6 | Driver’s Side Low-Beam Headlamp |
| 7 | Rear Window Washer, Headlamp Washer |
| 8 | Automatic Transfer Case |
| 9 | Windshield Washer |
| 10 | Powertrain Control Module B |
| 11 | Fog Lamps |
| 12 | Stoplamp |
| 13 | Cigarette Lighter |
| 14 | 2004-2005: Ignition Coils |
| 15 | Electric Adjustable Pedal |
| 16 | Truck Body Controller, Ignition 1 |
| 17 | Crank |
| 18 | Airbag |
| 19 | Trailer Electric Brake |
| 20 | Cooling Fan |
| 21 | Horn |
| 22 | Ignition E |
| 23 | Electronic Throttle Control |
| 24 | Instrument Panel Cluster, Driver Information Center |
| 25 | Automatic Shift Lock Control System |
| 26 | 2004: Backup 2005-2006: Engine 1 |
| 27 | 2004: Engine 1 2005-2006: Backup |
| 28 | Powertrain Control Module 1 |
| 29 | Oxygen Sensor |
| 30 | Air Conditioning |
| 31 | Truck Body Controller |
| 32 | Trailer |
| 33 | Anti-Lock Brakes (ABS) |
| 34 | Ignition A |
| 35 | Blower Motor |
| 36 | Ignition B |
| 50 | Passenger’s Side Trailer Turn |
| 51 | Driver’s Side Trailer Turn |
| 52 | Hazard Flashers |
| 53 | 2004: Electric Adjustable Pedal 2005-2006: Headlamp Driver Module |
| 54 | Air Injection Reactor (AIR) Solenoid |
| 56 | Air Injection Reactor (AIR) Pump |
| Relays | |
| 37 | Headlamp Washer |
| 38 | Rear Window Washer |
| 39 | Fog Lamps |
| 40 | Horn |
| 41 | Fuel Pump |
| 42 | Windshield Washer |
| 43 | High-Beam Headlamp |
| 44 | Air Conditioning |
| 45 | Cooling Fan |
| 46 | Headlamp Driver Module |
| 47 | Starter |
| 49 | Electric Adjustable Pedal |
| 55 | Air Injection Reactor (AIR) Solenoid |
| 57 | Powertrain (2006) |
| 58 | Vehicle Stability EnhancementSystem (StabiliTrak) (2006) |
| Miscellaneous | |
| 48 | Instrument Panel Battery |
L6 engine, 2007-2008
Assignment of the fuses and relay in the Underhood Fuse Box, L6 engine (2007, 2008)
| № | Usage |
|---|---|
| 1 | Electrically-Controlled Air Suspension |
| 2 | Passenger Side High-Beam Headlamp |
| 3 | Passenger Side Low-Beam Headlamp |
| 4 | Back-Up Trailer Lamps |
| 5 | Driver Side High-Beam Headlamp |
| 6 | Driver Side Low-Beam Headlamp |
| 7 | Windshield Wiper |
| 8 | Automatic Transfer Case |
| 9 | Windshield Washer |
| 10 | Powertrain Control Module B |
| 11 | Fog Lamps |
| 12 | Stoplamp |
| 13 | Cigarette Lighter |
| 14 | Not Used |
| 15 | Electric Adjustable Pedal |
| 16 | Truck Body Controller, Ignition 1 |
| 17 | Crank |
| 18 | Airbag |
| 19 | Trailer Electric Brake |
| 20 | Cooling Fan |
| 21 | Horn |
| 22 | Ignition E |
| 23 | Electronic Throttle Control |
| 24 | Instrument Panel Cluster, Driver Information Center |
| 25 | Automatic Shift Lock Control System |
| 26 | Transmission Control Module (TCM) Canister |
| 27 | Backup |
| 28 | Powertrain Control Module 1 |
| 29 | Oxygen Sensor |
| 30 | Air Conditioning |
| 31 | Truck Body Controller 1 |
| 32 | Trailer |
| 33 | Antilock Brakes (ABS) |
| 34 | Ignition A |
| 35 | Blower Motor |
| 36 | Ignition B |
| 50 | Passenger Side Trailer Turn |
| 51 | Driver Side Trailer Turn |
| 52 | Hazard Flashers |
| 53 | Headlamp Driver Module |
| 54 | Air Injection Reactor (AIR) Solenoid |
| 56 | Air Injection Reactor (AIR) Pump |
| 58 | Vehicle Stability Enhancement System (StabiliTrak) |
| 59 | Regulated Voltage Control |
| Relays | |
| 37 | Headlamp Washer |
| 38 | Rear Window Wiper/Washer |
| 39 | Fog Lamps |
| 40 | Horn |
| 41 | Fuel Pump |
| 42 | Windshield Washer |
| 43 | High-Beam Headlamp |
| 44 | Air Conditioning |
| 45 | Cooling Fan |
| 46 | Headlamp Driver Module |
| 47 | Starter |
| 49 | Electric Adjustable Pedal |
| 55 | Air Injection Reactor (AIR) Solenoid |
| 57 | Powertrain |
| Miscellaneous | |
| 48 | Instrument Panel Battery |
Underhood Fuse Box (2009)
Assignment of the fuses and relay in the Underhood Fuse Box (2009)
| № | Usage |
|---|---|
| 1 | Electrically-Controlled Air Suspension |
| 2 | Passenger Side High-Beam Headlamp |
| 3 | Passenger Side Low-Beam Headlamp |
| 4 | Back-Up Trailer Lamps |
| 5 | Driver Side High-Beam Headlamp |
| 6 | Driver Side Low-Beam Headlamp |
| 7 | Windshield Wiper |
| 8 | Active Transfer Case |
| 9 | Windshield Washer |
| 10 | Powertrain Control Module B |
| 11 | Fog Lamps |
| 12 | Stoplamp |
| 13 | Cigarette Lighter |
| 14 | Ignition Coils |
| 15 | Transmission Control Module Canister |
| 16 | Truck Body Controller, Ignition 1 |
| 17 | Crank |
| 18 | Airbag |
| 19 | Trailer Electric Brake |
| 21 | Horn |
| 22 | Ignition E |
| 23 | Electronic Throttle Control |
| 24 | Instrument Panel Cluster, Driver Information Center |
| 25 | Brake Transmission Shift Interlock |
| 26 | Engine 1 |
| 27 | Backup |
| 28 | Engine Control Module 1 |
| 29 | Engine Control Module |
| 30 | Air Conditioning |
| 31 | Injector A |
| 32 | Trailer |
| 33 | Antilock Brakes (ABS) |
| 34 | Ignition A |
| 35 | Blower |
| 36 | Ignition B |
| 50 | Passenger Side Trailer Turn |
| 51 | Driver Side Trailer Turn |
| 52 | Hazard Flashers |
| 53 | Transmission |
| 54 | Oxygen Sensor B |
| 55 | Oxygen Sensor A |
| 56 | Injector B |
| 57 | Headlamp Driver Module |
| 58 | Body Controller 1 |
| 59 | Electric Adjustable Pedals |
| 61 | Vehicle Stability Enhancement System |
| 62 | Regulated Voltage Control |
| 63 | Air Solenoid |
| 64 | Air Pump |
| Relays | |
| 37 | Headlamp Wiper |
| 38 | Rear Window Wiper/Washer |
| 39 | Fog Lamps |
| 40 | Horn |
| 41 | Fuel Pump |
| 42 | Windshield Washer |
| 43 | High-Beam Headlamp |
| 44 | Air Conditioning |
| 46 | Headlamp Driver Module |
| 47 | Starter |
| 49 | Electric Adjustable Pedal |
| 60 | Powertrain |
| 69 | Air Solenoid |
| Miscellaneous | |
| 48 | Instrument Panel Battery |
Fuse box diagrams (V8 Engine)
V8 engine, 2003-2004
Assignment of the fuses and relay in the Underhood Fuse Box, V8 engine (2003, 2004)
| № | Usage |
|---|---|
| 1 | Electrically-Controlled Air Suspension |
| 2 | Passenger’s Side High-Beam Headlamp |
| 3 | Passenger’s Side Low-Beam Headlamp |
| 4 | Back-Up-Trailer Lamps |
| 5 | Driver’s Side High-Beam Headlamp |
| 6 | Driver’s Side Low-Beam Headlamp |
| 7 | Rear Window Washer, Headlamp Washer |
| 8 | Automatic Transfer Case |
| 9 | Windshield Washer |
| 10 | Powertrain Control Module B |
| 11 | Fog Lamps |
| 12 | Stop Lamp |
| 13 | Cigarette Lighter |
| 14 | Ignition Coils |
| 15 | Canister Vent |
| 16 | TBC-Ignition 1 |
| 17 | Crank |
| 18 | Air Bag |
| 19 | Trailer Electric Brake |
| 20 | Cooling Fan |
| 21 | Horn |
| 22 | Ignition E |
| 23 | Electronic Throttle Control |
| 24 | Instrument Panel Cluster, Driver Information Center |
| 25 | Automatic Shift Lock Control System |
| 26 | 2003: Engine 1 2004: Backup |
| 27 | 2003: Backup 2004: Engine 1 |
| 28 | Powertrain Control Module 1 |
| 30 | Air Conditioning |
| 31 | Truck Body Controller |
| 32 | Trailer |
| 33 | Anti-Lock Brakes (ABS) |
| 34 | Ignition A |
| 35 | Blower Motor |
| 36 | Ignition B |
| 50 | Passenger’s Side Trailer Turn |
| 51 | Driver’s Side Trailer Turn |
| 52 | Hazard Flashers |
| 53 | Oxygen Sensor Bank B |
| 54 | Oxygen Sensor Bank A |
| 55 | Injector Bank A |
| 56 | Injector Bank B |
| 57 | Electric Adjustable Pedal |
| Relays | |
| 37 | Headlamp Washer |
| 38 | Rear Window Washer |
| 39 | Fog Lamps |
| 40 | Horn |
| 41 | Fuel Pump |
| 42 | Windshield Washer |
| 43 | High-Beam Headlamp |
| 44 | Air Conditioning |
| 45 | Cooling Fan |
| 46 | Headlamp Driver Module |
| 47 | Starter |
| 49 | Electric Adjustable Pedal |
| 58 | Ignition 1 |
| Miscellaneous | |
| 48 | Instrument Panel Battery |
V8 engine, 2005-2008
Assignment of the fuses and relay in the Underhood Fuse Box, V8 engine (2005-2008)
| № | Usage |
|---|---|
| 1 | Electrically-Controlled Air Suspension |
| 2 | Passenger Side High-Beam Headlamp |
| 3 | Passenger Side Low-Beam Headlamp |
| 4 | Back-Up-Trailer Lamps |
| 5 | Driver Side High-Beam Headlamp |
| 6 | Driver Side Low-Beam Headlamp |
| 7 | 2005-2006: Rear Window Washer, HeadlampWasher 2007-2008: Windshield Wiper |
| 8 | Automatic Transfer Case |
| 9 | Windshield Washer |
| 10 | Powertrain Control Module B |
| 11 | Fog Lamps |
| 12 | Stoplamp |
| 13 | Cigarette Lighter |
| 14 | Ignition Coils |
| 15 | 2005-2006: Canister Vent 2007-2008: Transmission Control Module / Canister Vent |
| 16 | Truck Body Controller, Ignition 1 |
| 17 | Crank |
| 18 | Airbag |
| 19 | Trailer Electric Brake |
| 20 | Cooling Fan |
| 21 | Horn |
| 22 | Ignition E |
| 23 | Electronic Throttle Control |
| 24 | Instrument Panel Cluster, Driver Information Center |
| 25 | Automatic Shift Lock Control System |
| 26 | Engine 1 |
| 27 | Backup |
| 28 | Powertrain Control Module 1 |
| 29 | Powertrain Control Module |
| 30 | Air Conditioning |
| 31 | Injector Bank A |
| 32 | Trailer |
| 33 | Antilock Brakes (ABS) |
| 34 | Ignition A |
| 35 | Blower Motor |
| 36 | Ignition B |
| 50 | Passenger Side Trailer Turn |
| 51 | Driver Side Trailer Turn |
| 52 | Hazard Flashers |
| 53 | Transmission |
| 54 | Oxygen Sensor Bank B |
| 55 | Oxygen Sensor Bank A |
| 56 | Injector Bank B |
| 57 | Headlamp Driver Module |
| 58 | Body Controller 1 |
| 59 | Electric Adjustable Pedal |
| 61 | Vehicle Stability Enhancement System (StabiliTrak) |
| 62 | Regulated Voltage Control |
| Relays | |
| 37 | Headlamp Washer |
| 38 | Rear Window Wiper |
| 39 | Fog Lamps |
| 40 | Horn |
| 41 | Fuel Pump |
| 42 | Windshield Washer |
| 43 | High-Beam Headlamp |
| 44 | Air Conditioning |
| 45 | Cooling Fan |
| 46 | Headlamp Driver Module |
| 47 | Starter |
| 49 | Electric Adjustable Pedal |
| 60 | Powertrain |
| Miscellaneous | |
| 48 | Instrument Panel Battery |
Rear Underseat Fuse Box
Fuse box location
It is located under of the left rear seat, under two covers.
Fuse box diagram (TrailBlazer)
Assignment of the fuses in the Rear Underseat Box (TrailBlazer, 2002-2009)
| № | Usage |
|---|---|
| 01 | Passenger Door Control Module |
| 02 | Driver Door Control Module |
| 03 | Liftgate Module 2 |
| 04 | Truck Body Controller 3 |
| 05 | Rear Fog Lamps |
| 06 | 2002-2003: Liftgate Module/Driver Seat Module 2004-2009: Blank |
| 07 | Truck Body Controller 2 |
| 08 | Power Seats |
| 09 | 2002-2003: Blank 2003-2009: Rear Wiper |
| 10 | Driver Door Module |
| 11 | Amplifer |
| 12 | Passenger Door Module |
| 13 | Rear Climate Controls |
| 14 | Driver Side Rear Parking Lamps |
| 15 | 2002-2003: Auxiliarv Power 2 2003-2009: Blank |
| 16 | Vehicle Center High-Mounted Stoplamp (CHMSL) |
| 17 | Passenger Side Rear Parking Lamps |
| 18 | Locks |
| 19 | 2002-2003: Blank 2003-2009: Liftgate Module/Driver Seat Module |
| 20 | 2002-2004: Sunroof 2005-2009: Blank |
| 21 | Lock |
| 23 | Blank |
| 24 | Unlock |
| 25 | Blank |
| 26 | Blank |
| 27 | OnStar Overhead Battery, OnStar System |
| 28 | 2002-2004: Blank 2005-2009: Sunroof |
| 29 | Not Used |
| 30 | Parking Lamps |
| 31 | Truck Body Controller Accessory |
| 32 | Truck Body Controller 5 |
| 33 | Front Wipers |
| 34 | Vehicle Stop |
| 35 | 2002-2004: Blank 2005-2009: Transmission Control Module |
| 36 | Heat Ventilation Air Conditioning B |
| 37 | Front Parking Lamps |
| 38 | Driver Side Turn Signal |
| 39 | Heat Ventilation Air Conditioning 1 |
| 40 | Truck Body Controller 4 |
| 41 | Radio |
| 42 | Trailer Park |
| 43 | Passenger Side Turn Signal |
| 44 | Heat Ventilation Air Conditioning |
| 45 | Rear Fog Lamps |
| 46 | Auxiliary Power 1 |
| 47 | Ignition 0 |
| 48 | Four-Wheel Drive |
| 49 | Blank |
| 50 | Truck Body Controller Ignition |
| 51 | Brakes |
| 52 | Truck Body Controller Run |
Fuse box diagram (TrailBlazer EXT)
Assignment of the fuses in the Rear Underseat Box (TrailBlazer EXT, 2004-2006)
| № | Usage |
|---|---|
| 01 | Right Door Control Module |
| 02 | Left Door Control Module |
| 03 | Liftgate Module 2 |
| 04 | Truck Body Controller 3 |
| 05 | Rear Fog Lamps |
| 06 | Blank |
| 07 | Truck Body Controller 2 |
| 08 | Power Seats |
| 09 | Rear Wiper |
| 10 | Driver Door Module |
| 11 | Amplifier |
| 12 | Passenger Door Module |
| 13 | Rear Climate Controls |
| 14 | Left Rear Parking Lamps |
| 15 | Blank |
| 16 | Vehicle Center High-Mounted Stop Lamp |
| 17 | Right Rear Parking Lamps |
| 18 | Locks |
| 19 | Liftgate Module/Driver Seat Module |
| 20 | Vent Window |
| 21 | Lock |
| 22 | Retained Accessory Power |
| 23 | Blank |
| 24 | Unlock |
| 25 | Blank |
| 26 | Blank |
| 27 | OnStar Overhead Battery, OnStar System |
| 28 | Sunroof |
| 29 | Rainsense Wipers |
| 30 | Parking Lamps |
| 31 | Truck Body Controller Accessory |
| 32 | Truck Body Controller 5 |
| 33 | Front Wipers |
| 34 | Vehicle Stop |
| 35 | Transmission Control Module |
| 36 | Heat Ventilation Air Conditioning B |
| 37 | Front Parking Lamps |
| 38 | Left Turn Signal |
| 39 | Heat Ventilation Air Conditioning 1 |
| 40 | Truck Body Controller 4 |
| 41 | Radio |
| 42 | Trailer Park |
| 43 | RightTurn Signal |
| 44 | Heat Ventilation Air Conditioning |
| 45 | Rear Fog Lamps |
| 46 | Auxiliary Power 1 |
| 47 | Ignition 0 |
| 48 | Four-Wheel Drive |
| 49 | Blank |
| 50 | Truck Body Controller Ignition |
| 51 | Brakes |
| 52 | Truck Body Controller Run |
| BLANK | Not Used |
Conclusion
For owners and enthusiasts of classic Chevrolet TrailBlazer 2002-2009, understanding the fuse box and relay systems is essential for vehicle maintenance. Regular inspection and maintenance of these components helped ensure the vehicle’s longevity and reliability, preserving its status as a symbol of Chevrolet’s craftsmanship and innovation in the automotive industry during that era.