Engine Compartment Fuse Block
The fuse block is located under the hood in the engine compartment on the driver’s side of the vehicle.
Engine L6
| Mini fuses | 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 Wipers |
| 10 | Powertrain Control Module B |
| 11 | Fog Lamps |
| 12 | Stop Lamp |
| 13 | Cigarette Lighter |
| 14 | Ignition Coils |
| 15 | Blank |
| 16 | TBD — 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 | Backup |
| 27 | Engine 1 |
| 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 | Electric Adjustable Pedal |
| 54 | A.I.R. Solenoid |
| 56 | A.I.R. Pump |
| Relays | Usage |
| 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 | A.I.R. Solenoid |
| Miscellaneous | Usage |
| 48 | Instrument Panel Battery |
| 49 | Blank |
Engine V8
| Mini fuses | 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 Wipers |
| 10 | Powertrain Control Module B |
| 11 | Fog Lamps |
| 12 | Stop Lamp |
| 13 | Cigarette Lighter |
| 14 | Ignition Coils |
| 15 | Canister Vent |
| 16 | TBD — 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 | Backup |
| 27 | 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 | Usage |
| 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 | Usage |
| 48 | Instrument Panel Battery |
Rear Underseat Fuse Block
The rear underseat fuse block is located under the rear seat on the driver’s side of the vehicle.
Trailblazer
| Fuses | 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 | Sunroof |
| 21 | Lock |
| 23 | Blank |
| 24 | Unlock |
| 25 | Blank |
| 26 | Blank |
| 27 | OH Battery/OnStar System |
| 29 | Rainsense Wipers |
| 30 | Parking Lamps |
| 31 | Truck Body Controller Accessory |
| 32 | Truck Body Controller 5 |
| 33 | Front Wipers |
| 34 | Vehicle Stop |
| 35 | Blank |
| 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 | Right 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 |
TrailBlazer EXT
| Fuses | 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 | OH 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 | Blank |
| 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 | Right 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 |
WARNING: Terminal and harness assignments for individual connectors will vary depending on vehicle equipment level, model, and market.