The third generation of the GMC Sierra was produced in 2013, 2014, 2015, 2016, 2017. In our post, we’ll go over the fuses and relays in the GMC Sierra 3G, with diagrams of the fuse box, where they’re located, and examples of how they look like. We’ll also point out the fuse that controls the cigarette lighter.
The fuse and relay assignment may vary from that shown and depends on the year of manufacture and the level of electrical equipment in your vehicle.
Passenger compartment
Left fuse box
The first fuse box is located in the left end of the dashboard.
Diagram
Assignment
| 1 | Accessory power outlet 2 |
| 2 | Special equipment option/Retained accessory power |
| 3 | Universal remote system/lnterior rearview mirror |
| 6 | Body control module 3 |
| 7 | Body control module 5 |
| 8 | Driver window switch/ Mirror switch |
| 9 | Not Used |
| 10 | Accessory power outlet/Retained accessory power |
| 11 | Accessory power outlet battery |
| 12 | Accessory power outlet 1/ Cigarette lighter |
| 13 | Discrete logic ignition switch |
| 14 | Switch backlighting |
| 17 | Body control module 1 |
| 19 | — |
| 20 | — |
| 22 | Heating, ventilation, and air conditioning/ Auxiliary heating, ventilation, and air conditioning/lgnition |
| 23 | Instrument cluster/ Ignition sensing diagnostic module/ Ignition |
| 24 | Not Used |
| 25 | Data link connector/ Driver seat module |
| 26 | Passive entry/Passive start/Heating, ventilation, and air conditioning |
| 27 | Not Used |
| 28 | Not Used |
| 29 | Park enable/ Electrically adjustable pedals |
| 30 | Special equipment option |
| 31 | Accessory/ Run/Crank |
| 32 | Heated steering wheel |
| 33 | Not Used |
| 34 | Instrument cluster |
| 36 | Not Used |
| 37 | Not Used |
| 38 | 4WD transfer case electronic control |
| 40 | Left doors |
| 41 | Driver power seat |
| 43 | Left heated, cooled or ventilated seats (if equipped) |
| 44 | Right heated, cooled or ventilated seats (if equipped) |
| 45 | — |
Some relays are attached to the back of the fuse box.
- 49 – Retained accessory power
- 50 – Run/Crank
Right fuse box
The first fuse box is located in the right end of the dashboard.
Location
Diagram
Designation
| 1 | Accessory power outlet 3 |
| 2 | Accessory power outlet 4 |
| 7 | Body control module 4 |
| 8 | Body control module 8 |
| 9 | Rear seat entertainment |
| 10 | Cargo lamp |
| 15 | Steering wheel controls |
| 18 | Radio |
| 19 | Not Used |
| 20 | Sunroof |
| 23 | Airbag/ Info |
| 26 | Export/ Power take off/ Special equipment option/Battery 1 |
| 27 | Obstacle detection/ USB ports |
| 28 | Body control module 2 |
| 32 | Special equipment option/Battery 2 |
| 35 | Air conditioning inverter |
| 36 | Amplifier |
| 37 | Battery system |
| 39 | Rear sliding window |
| 42 | Right door window motor |
| 43 | Front blower |
| 44 | Special equipment option |
| 45 | Body control module 6 |
| 46 | Body control module 7 |
| 47 | Passenger seat |
Relays are attached to the back of the fuse box.
- 50 – Retained accessory power
- 51 – Rear sliding window open
- 52 – Rear sliding window close
Engine compartment
Under the hood on the left hand side is the main fuse and relay box.
Diagram
| 1 | Trailer brake |
| 2 | Trailer battery |
| 3 | Antilock brake system pump |
| 4 | Instrument panel BEC 1 |
| 5 | Passenger motorized seat belt |
| 6 | 4WD transfer case electronic control |
| 7 | Electric park brake |
| 8 | Instrument panel BEC 2 |
| 9 | Driver motorized seat belt |
| 10 | Rear window defogger |
| 11 | Starter |
| 12 | Cooling fan 1 |
| 13 | Cooling fan 2 |
| 14 | Left trailer stop/ Turn signal lamps |
| 15 | Trailer parking lamps |
| 16 | Trailer reverse lamps |
| 17 | Right trailer stop/ Turn signal lamps |
| 18 | Fuel pump |
| 19 | Integrated chassis control module |
| 20 | Electronic suspension control module |
| 21 | Fuel pump power module |
| 22 | Upfitter 1 |
| 23 | Upfitter 2 |
| 24 | Front wiper |
| 25 | Antilock brake system valve |
| 26 | Upfitter 2 |
| 27 | Upfitter 3 |
| 28 | Right parking lamps |
| 29 | Left parking lamps |
| 30 | Upfitter 3 |
| 31 | Upfitter 4 |
| 32 | Upfitter 4 |
| 33 | Reverse lamps |
| 34 | Engine control module/Ignition |
| 35 | Air conditioning clutch |
| 36 | Heated mirrors |
| 37 | Upfitter 1 |
| 38 | Center high-mounted stoplamp |
| 39 | Miscellaneous/ Ignition |
| 40 | Transmission/ Ignition |
| 41 | Fuel pump 2 |
| 42 | Cooling fan clutch |
| 43 | Engine |
| 44 | Fuel injectors A–odd |
| 45 | Fuel injectors B–even |
| 46 | O2 Sensor B |
| 47 | Throttle control |
| 48 | Horn |
| 49 | Fog lamps |
| 50 | O2 Sensor A |
| 51 | Engine control module |
| 52 | Interior heater |
| 53 | Accessory power module/TPM pump |
| 54 | Front washer |
| 55 | Air conditioning/ Battery regulated voltage control |
| 56 | Air conditioning module/ Battery pack |
| 57 | Transmission control module/ Engine control module |
| 58 | Headlamps |
| 74 | Electric running boards (if equipped) |
| 76 | Fuel pump prime / MGU motor |
| 77 | Cabin pump motor |
| 79 | Vacuum pump |
| Relays | |
| 59 | Fuel pump |
| 60 | Upfitter 2 |
| 61 | Upfitter 3 |
| 62 | Upfitter 4 |
| 63 | Trailer parking lamps |
| 64 | Run/Crank |
| 65 | Upfitter 1 |
| 66 | Fuel pump 2 |
| 67 | Air conditioning control |
| 68 | Starter |
| 69 | Rear window defogger |
| 70 | Engine control module |
| 71 | Vacuum pump/ Cooling fan clutch |
| 72 | CKT 95 |
| 73 | CKT 92 |
| 75 | Fuel pump prime/ MGU motor |
| 78 | Vacuum pump switch |
Want to help flesh out the material, post in the comments.