ELECTRICAL & FUSES
2015 Chevrolet Silverado 1500 Engine Compartment Fuses
The underhood fuse and relay block protects multiple powertrain and body circuits; position assignments depend on equipment.
Confirm the engine, trim, drivetrain, market and installed equipment before using a part number, capacity or repair procedure.
2015 Silverado 1500 underhood fuse and relay chart
Browse the entries below.
| Position | Device family | Protected circuit / function |
|---|---|---|
| 1 | Micro J-case | Trailer brake feed |
| 2 | Micro J-case | Trailer battery feed |
| 3 | J-case | ABS pump |
| 4 | J-case | Instrument panel electrical centre 1 |
| 5 | J-case | Spare |
| 6 | J-case | 4WD transfer case control |
| 7 | J-case | Spare |
| 8 | J-case | Instrument panel electrical centre 2 |
| 9 | J-case | Spare |
| 10 | J-case | Rear window defogger |
| 11 | J-case | Starter |
| 12 | J-case | Cooling fan 1 |
| 13 | J-case | Cooling fan 2 |
| 14 | Mini, 2 pin | Trailer left stop/turn lamps |
| 15 | Mini, 2 pin | Trailer parking lamps |
| 16 | Mini, 2 pin | Trailer reverse lamp |
| 17 | Mini, 2 pin | Trailer right stop/turn lamps |
| 18 | Micro, 2 pin | Fuel pump |
| 19 | Micro, 2 pin | Integrated chassis control module |
| 20 | Micro, 2 pin | Electronic suspension control |
| 21 | Micro, 2 pin | Fuel pump power module |
| 22 | Micro, 2 pin | Upfitter switch 1 |
| 23 | Micro, 2 pin | Upfitter 2 |
| 24 | Micro, 2 pin | Front windshield wiper |
| 25 | Micro, 2 pin | ABS valves |
| 26 | Micro, 2 pin | Upfitter switch 2 |
| 27 | Micro, 2 pin | Upfitter switch 3 |
| 28 | Micro, 2 pin | Right parking lamps |
| 29 | Micro, 2 pin | Left parking lamps |
| 30 | Micro, 2 pin | Upfitter 3 |
| 31 | Micro, 2 pin | Upfitter switch 4 |
| 32 | Micro, 2 pin | Upfitter 4 |
| 33 | Micro, 2 pin | Reverse lamps |
| 34 | Micro, 2 pin | Engine control module ignition |
| 35 | Micro, 2 pin | A/C compressor clutch |
| 36 | Micro, 2 pin | Heated outside mirrors |
| 37 | Micro, 2 pin | Upfitter 1 |
| 38 | Micro, 2 pin | Center high-mounted stop lamp |
| 39 | Micro, 2 pin | Miscellaneous ignition |
| 40 | Micro, 2 pin | Transmission ignition |
| 41 | Micro, 2 pin | Fuel pump 2 |
| 42 | Micro, 2 pin | Cooling fan clutch |
| 43 | Micro, 2 pin | Engine |
| 44 | Micro, 2 pin | Odd-cylinder fuel injectors |
| 45 | Micro, 2 pin | Even-cylinder fuel injectors |
| 46 | Micro, 2 pin | Oxygen sensor B |
| 47 | Micro, 2 pin | Throttle control |
| 48 | Micro, 2 pin | Horn |
| 49 | Micro, 2 pin | Fog lamps |
| 50 | Micro, 2 pin | Oxygen sensor A |
| 51 | Micro, 2 pin | Engine control module |
| 52 | Micro, 2 pin | Interior heater |
| 53 | Micro, 2 pin | Spare |
| 54 | Micro, 2 pin | Active grille shutter |
| 55 | Micro, 2 pin | Front washer |
| 56 | Micro, 3 pin | A/C compressor and regulated battery voltage control |
| 57 | Micro, 3 pin | A/C compressor module/battery pack |
| 58 | Micro, 3 pin | Transmission control module/engine control module |
| 59 | Micro, 3 pin | Headlamps |
| 60 | Micro relay | Fuel pump |
| 61 | Micro relay | Upfitter 2 |
| 62 | Micro relay | Upfitter 3 |
| 63 | Micro relay | Upfitter 4 |
| 64 | Micro relay | Trailer parking lamps |
| 65 | Micro relay | Run/crank |
| 66 | Micro relay | Upfitter 1 |
| 67 | Micro relay | Fuel pump 2 |
| 68 | Micro relay | Air conditioning control |
| 69 | Micro relay | Starter |
| 70 | Mini relay | Rear window defogger |
| 71 | Mini relay | Engine control module |
| 72 | Solid-state relay | Cooling fan clutch |
Positions 1–72 reflect the 2015 GM owner manual. Use the cover and your actual fuse marking for amperage; the owner chart does not state every rating. Some optional or spare positions may be empty.
Accessing the block
The engine-compartment block sits on the driver side under the hood. The 2015 owner manual groups its 72 positions into J-case, mini, micro and relay families. The table below gives the position, device family and associated function so you can search for a failed circuit without leaving the page.
Testing a circuit safely
If a component has stopped working, confirm whether the relevant fuse actually has power on the appropriate side of the circuit before replacing parts. A blown fuse may indicate a short, damaged accessory wire or failed component. Never probe high-current terminals without proper training.
- Compare the moulded lid diagram with the manual for your exact truck.
- Some cavities are unused on trucks without optional equipment.
- Never up-rate a fuse or bypass a protection device.
Using the factory circuit legend
Find the cavity number in the owner manual’s engine-compartment chart, then compare it with the imprint inside your actual lid. A maxi fuse, micro fuse and relay are not interchangeable even when they are close together. If the chart or lid cannot be read, obtain the correct factory diagram before installing anything.
Use the correct model-year manual and current service information. Stop if instructions or safety precautions are unclear, and use a qualified technician for work you cannot verify.
References and further reading
- Official GM 2015 Silverado Owner Manual (second printing)
- GM 2015 Silverado electrical body-builder service reference
This independent guide is not endorsed by the vehicle manufacturer. Let us know if you spot an error.