The Chevrolet Tahoe and Suburban, produced from 2015 to 2020 under the GMT K2YC/G and K2UC/G platforms, are popular full-size SUVs known for their power, versatility, and spacious interiors. These vehicles are built to handle a variety of driving conditions, from daily commutes to heavy-duty towing, making them favorites among families and outdoor enthusiasts alike. A key aspect of their reliability and functionality is their electrical system, with the fuse box and relays playing vital roles in ensuring all systems operate smoothly.
The fuse box in the 2015-2020 Chevrolet Tahoe and Suburban is crucial for protecting the vehicle’s electrical circuits. These circuits power essential systems such as engine management, lighting, infotainment, climate control, and power accessories like windows, seats, and the liftgate. These models typically feature two primary fuse boxes: one in the engine compartment and another within the cabin, often under the dashboard or in the rear cargo area. The engine compartment fuse box manages high-power systems linked to the engine and transmission, while the interior fuse box covers systems related to comfort and convenience.
Each fuse within these boxes is connected to a specific circuit, designed to blow if there’s an overload or short circuit, thus preventing damage to the system and avoiding potential electrical fires. For example, if the air conditioning or power windows stop working, checking the associated fuse is a crucial first step in diagnosis.
Relays in these vehicles are electrically operated switches that control the power supply to high-current systems, such as the starter motor, fuel pump, and cooling fans. Relays allow these high-demand systems to be operated by lower-power control circuits, which ensures the vehicle’s wiring and switches aren’t overloaded, preserving safety and efficiency. For instance, if a relay controlling the cooling fan fails, it could lead to overheating, or if the starter relay fails, the engine might not start.
Regular inspection and maintenance of the fuse boxes and relays are essential to preventing electrical issues in the Chevrolet Tahoe and Suburban. A blown fuse or a faulty relay can lead to significant system failures, and addressing these promptly can save on costly repairs and ensure the vehicle remains dependable.
Understanding the importance of the fuse box and relays in these SUVs helps owners maintain their vehicles’ electrical systems, ensuring all features continue to function as intended. Proper maintenance of these components contributes to the overall reliability and longevity of the Tahoe and Suburban, making them trusted vehicles for both everyday use and extended adventures.
MUST READ: DYI – How to Check Car Fuses?
(2015-2020) Chevrolet Tahoe & Suburban (GMT K2YC/G / K2UC/G) 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 Tahoe & Suburban (GMT K2YC/G / K2UC/G) 2015-2020 fuse assignment
- Cigar lighter (power outlet) fuses in the Chevrolet Suburban (Tahoe) are the fuses №. 4 (Accessory Power Outlet 1), №. 50 (Accessory Power Outlet 2) in the Driver’s Side Instrument panel fuse box; fuses №. 4 (Accessory Power Outlet 4), №. 50 (Accessory Power Outlet 3) in the Passenger’s Side Instrument panel fuse box; fuse №. 14 (Rear accessory power outlet) in the Luggage Compartment Fuse Box.
Year of production: from 2015, 2016, 2017, 2018, 2019, 2020
Instrument Panel Fuse Box №. 1 (Driver’s Side)
Fuse box location
It is located on the driver’s side of the instrument panel, behind the cover.
Fuse box diagram
Assignment of the fuses in the Instrument Panel Fuse Box №. 1 (2015-2020)
| № | Usage |
|---|---|
| 1 | Not used |
| 2 | Not used |
| 3 | Not used |
| 4 | Accessory Power Outlet 1 |
| 5 | Retained Accessory Power/Accessory |
| 6 | Accessory power outlet from battery power |
| 7 | 2015-2018: Universal Garage Door Opener/Inside Rear View Mirror. 2019-2020: Universal garage door opener/SEO Roof beacon switch |
| 8 | SEO / Retained Accessory Power |
| 9 | Not used |
| 10 | Body Control Module 3 |
| 11 | Body Control Module 5 |
| 12 | Steering Wheel Controls Backlighting |
| 13 | Not used |
| 14 | Not used |
| 15 | Not used |
| 16 | Discrete Logic Ignition Sensor |
| 17 | 2015-2018: Video processing module. 2019-2020: Video processing module/Virtual key module |
| 18 | Mirror Window Module |
| 19 | Body Control Module 1 |
| 20 | Front Bolster (if equipped) |
| 21 | Not used |
| 22 | Not used |
| 23 | Not used |
| 24 | 2015-2016: Heater, Ventilation and Air Conditioning Ignition/Heater, Ventilation and Air Conditioning Auxiliary. 2017-2020: HVAC/Ignition |
| 25 | Instrument cluster/Ignition sensing diagnostic module/Ignition |
| 26 | 2015-2018: Tilt Column/SEO, Tilt Column Lock 1/SEO. 2019-2020: Tilt column/Tilt column lock 1/SEO 1/SEO 2 |
| 27 | Data link connector/Driver seat module |
| 28 | 2015-2018: Passive Entry/Passive Start/Heater, Ventilation and Air Conditioning Battery. 2019-2020: Passive entry, Passive start/HVAC battery/CGM |
| 29 | Content theft deterrent |
| 30 | Not used |
| 31 | Not used |
| 32 | Not used |
| 33 | 2015-2017: SEO/Automatic Level Control. 2018-2020: SEO automatic level control/Left heated seat |
| 34 | Park Enable Electric Adjustable Pedal (if equipped) |
| 35 | Not used |
| 36 | Miscellaneous/Run crank |
| 37 | Heated Steering Wheel |
| 38 | Steering Column Lock 2 (if equipped) |
| 39 | Instrument Cluster Battery |
| 40 | Not used |
| 41 | Not used |
| 42 | Euro Trailer (if equipped) |
| 43 | Left Doors |
| 44 | Driver Power Seat |
| 45 | Not used |
| 46 | Right heated, cooled, or ventilated seat (if equipped) |
| 47 | Left heated, cooled, or ventilated seat (if equipped) |
| 48 | Not used |
| 49 | Not used |
| 50 | Accessory Power Outlet 2 |
| 51 | Not used |
| 52 | Retained Accessory Power Relay |
| 53 | Run/Crank Relay |
| 54 | Not used |
| 55 | Not used |
| 56 | Not used |
Instrument Panel Fuse Box №. 2 (Passenger’s Side)
Fuse box location
It is located on the passenger side of the instrument panel, behind the cover.
Fuse box diagram
Assignment of the fuses in the Instrument Panel Fuse Box №. 2 (2015-2020)
| № | Usage |
|---|---|
| 1 | Not used |
| 2 | Not used |
| 3 | Not used |
| 4 | Accessory Power Outlet 4 |
| 5 | Not used |
| 6 | Not used |
| 7 | Not used |
| 8 | Not used / Glove box |
| 9 | Not used |
| 10 | Not used |
| 11 | Not used |
| 12 | Steering Wheel Controls |
| 13 | Body Control Module 8 |
| 14 | Not used |
| 15 | Not used |
| 16 | Not used |
| 17 | Not used |
| 18 | Not used |
| 19 | Body Control Module 4 |
| 20 | Rear Seat Entertainment |
| 21 | Sunroof/beacon upffiter |
| 22 | Not used |
| 23 | Not used |
| 24 | Not used |
| 25 | Not used |
| 26 | Infotainment/Airbag |
| 27 | Spare/RF window switch/Rain sensor |
| 28 | Obstacle Detection/USB |
| 29 | Radio |
| 30 | Not used |
| 31 | Not used |
| 32 | Not used |
| 33 | Not used |
| 34 | Not used |
| 35 | Not used |
| 36 | Special equipment option B2 |
| 37 | Special equipment option |
| 38 | Body Control Module 2 |
| 39 | A/C Inverter |
| 40 | Not used |
| 41 | Not used |
| 42 | Not used |
| 43 | Not used |
| 44 | Right Door Window Motor |
| 45 | Front Blower |
| 46 | Body Control Module 6 |
| 47 | Body Control Module 7 |
| 48 | Amplifier |
| 49 | Right Front Seat |
| 50 | Accessory Power Outlet 3 |
| 51 | Not used |
| 52 | Retained Accessory Power Relay |
| 53 | Not used |
| 54 | Not used |
| 55 | Not used |
| 56 | Not used |
Engine Compartment Fuse Box
Fuse box location
It is located in the engine compartment on the driver’s side.
Fuse box diagram
Assignment of the fuses and relay in the Engine Compartment (2015-2020)
| № | Usage |
|---|---|
| 1 | 2015-2019: Electric Running Boards. 2020: Power Assist Steps |
| 2 | Antilock Brake System Pump |
| 3 | Interior BEC LT1 |
| 4 | Passenger motorized safety belt |
| 5 | Suspension Leveling Compressor |
| 6 | 4WD Transfer Case Electronic Control |
| 7 | Not used |
| 8 | Not used |
| 9 | Fuel pump relay / Not Used |
| 10 | Electric Parking Brake / Not Used |
| 11 | Not used |
| 12 | Not used |
| 13 | Interior BEC LT2 |
| 14 | Rear BEC 1 |
| 15 | Not used |
| 16 | Not used |
| 17 | Driver motorized safety belt |
| 18 | Not used |
| 19 | Not used |
| 20 | Not used |
| 21 | Automatic headlamp leveling/ Exhaust solenoid |
| 22 | Fuel pump |
| 23 | Integrated Chassis Control Module |
| 24 | Real-Time Dampening |
| 25 | Fuel Pump Power Module |
| 26 | Active hydraulic assist/Battery regulated voltage control |
| 27 | Not used |
| 28 | Upfitter 2 |
| 29 | Upfitter 2 Relay |
| 30 | Wiper |
| 31 | Trailer interface module (TIM) |
| 32 | Not used |
| 33 | Not used |
| 34 | Reverse lamps |
| 35 | Antilock brake system valve |
| 36 | Trailer Brakes |
| 37 | Upfitter 3 Relay |
| 38 | Not used |
| 39 | Right trailer stoplamp/Turn signal lamp |
| 40 | Left trailer stoplamp/turn signal lamp |
| 41 | Trailer parking lamps |
| 42 | Right parking lamps |
| 43 | Left parking lamps |
| 44 | Upfitter 3 |
| 45 | Automatic Level Control Run/Crank |
| 46 | Not used |
| 47 | Upfitter 4 |
| 48 | Upfitter 4 Relay |
| 49 | Reverse Lamps |
| 50 | Not used |
| 51 | Parking Lamp Relay |
| 52 | Not used |
| 53 | Not used |
| 54 | Not used |
| 55 | Not used |
| 56 | Not used |
| 57 | Not used |
| 58 | Not used |
| 59 | Euro Trailer |
| 60 | A/C control |
| 61 | Not used |
| 62 | Not used |
| 63 | Upfitter 1 |
| 64 | Not used |
| 65 | Not used |
| 66 | Not used |
| 67 | Trailer Battery |
| 68 | Not used / Secondary fuel pump |
| 69 | RC Upfitter 3 and 4 |
| 70 | VBAT Upfitter 3 and 4 |
| 71 | Not used |
| 72 | Upfitter 1 Relay |
| 73 | Not used |
| 74 | Engine Control Module Ignition |
| 75 | Miscellaneous Ignition / Spare |
| 76 | Transmission Ignition |
| 77 | RC Upfitter 1 and 2 |
| 78 | VBAT Upfitter 1 and 2 |
| 79 | Not used |
| 80 | Not used |
| 81 | Not used |
| 82 | Not used |
| 83 | Euro Trailer / RC |
| 84 | Run/Crank Relay |
| 85 | Not used |
| 86 | Not used |
| 87 | Engine / MAF/IAT/Humidity/ TIAP sensor |
| 88 | Injector A – Odd |
| 89 | Injector B – Even |
| 90 | Oxygen Sensor B |
| 91 | Throttle Control |
| 92 | Engine Control Module Relay |
| 93 | Horn |
| 94 | Fog Lamps |
| 95 | High-Beam Headlamps |
| 96 | Not used |
| 97 | Not used |
| 98 | Not used |
| 99 | Not used |
| 100 | Oxygen Sensor A |
| 101 | Engine Control Module |
| 102 | Engine Control Module/Transmission Control Module |
| 103 | Auxiliary Interior Heater |
| 104 | Starter |
| 105 | Not used |
| 106 | Not used |
| 107 | AeroShutter |
| 108 | Not used |
| 109 | Police Upfitter |
| 110 | Not used |
| 111 | Not used |
| 112 | Starter Relay |
| 113 | Not used |
| 114 | Front Windshield Washer |
| 115 | Rear Window Washer |
| 116 | Left cooling fan |
| 117 | Fuel pump prime |
| 118 | Not used |
| 119 | Not used |
| 120 | Fuel pump prime relay |
| 121 | Right HID headlamp |
| 122 | Left HID Headlamp |
| 123 | Right cooling fan |
Luggage Compartment Fuse Box
Fuse box location
It is located in the left side of the luggage compartment behind the cover.
Fuse box diagram
Assignment of the fuses and relay in the Luggage Compartment (2015-2020)
| № | Usage |
|---|---|
| 2 | Left heated second row seat / Not used |
| 3 | Right heated second row seat |
| 4 | Heated Mirrors |
| 5 | Liftgate |
| 6 | Glass Breakage |
| 7 | Liftglass |
| 8 | Liftgate Module Logic |
| 9 | Rear Wiper |
| 10 | Rear Heater, Ventilation and Air Conditioning Blower |
| 11 | Second Row Seat |
| 12 | Liftgate module |
| 13 | Third row seat |
| 14 | Rear accessory power outlet |
| 15 | Rear defogger |
| Relay: | |
| 1 | Rear defogger |
| 16 | Liftgate |
| 17 | Liftglass |
| 18 | Rear fog lamp (if equipped) |
| 19 | Rear Fog Lamp (if equipped) |
| 20 | Heated mirror |
Conclusion
For owners and enthusiasts of classic Chevrolet Tahoe & Suburban (GMT K2YC/G / K2UC/G) 2015-2020, 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.
