The Cadillac XT4, manufactured from 2019 to 2022, is a compact luxury crossover SUV renowned for its stylish design, advanced technology features, and dynamic performance. Its electrical system, comprising the fuse box and relay components, is integral to its operational capabilities.
In the Cadillac XT4, the fuse box is responsible for safeguarding various electrical circuits throughout the vehicle. Each fuse is designed to protect specific systems such as the engine control module, lighting, entertainment, climate control, and other critical functions. If an electrical overload or short circuit occurs, the fuse will blow, interrupting the circuit to prevent damage to associated components.
Relays in the Cadillac XT4 act as electrically operated switches that control high-current circuits. These relays enable the precise activation and deactivation of functions such as the starter motor, fuel pump, air conditioning compressor, and power windows or seats. By efficiently managing power distribution, relays contribute to the vehicle’s overall reliability and performance.
Routine inspection and maintenance of the fuse box and relays are essential to ensure the Cadillac XT4 operates smoothly. This includes checking fuses for signs of wear or damage, ensuring relay connections are secure, and promptly addressing any electrical issues that may arise. Proper care of these components helps maintain the vehicle’s electrical integrity, enhancing safety and driving comfort in the Cadillac XT4.
MUST READ: DYI – How to Check Car Fuses?
(2019-2022) Cadillac XT4 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.
Cadillac XT4 2019-2022 fuse assignment
- Cigar lighter (power outlet) fuses in the Cadillac XT4 is the fuses F5 (Auxiliary power outlet – cargo), F37 (Auxiliary power outlet – front), F43 (Auxiliary power outlet – console (circuit breaker)), and F44 (Auxiliary power outlet – console) in the Instrument panel fuse box.
Year of production: 2019, 2020, 2021, 2022
Passenger compartment
The fuse box is located on the driver’s side of the instrument panel behind the cover.
To access, remove the panel, starting at the top. Once clips are disengaged, the tabs along the bottom of the door can be disengaged from the instrument panel to remove the door.
To reinstall the door, place the bottom tabs into the slots, and rotate the door into position, engaging the clips.
Engine compartment
Fuse box diagrams
2019, 2020, 2021
Instrument panel fuse block
Assignment of the fuses and relays in the instrument panel (2019, 2020, 2021)
| № | Usage |
|---|---|
| F1 | Left power window |
| F2 | Right power window |
| F3 | Not Used |
| F4 | DC DC battery 2/1 |
| F5 | Auxiliary power outlet – cargo |
| F6 | Heated seat battery 1 |
| F7 | Heated seat battery 2 |
| F8 | Body control module 3 |
| F9 | Electric parking brake switch |
| F10 | Body control module 2 (stop/start) |
| F11 | Not Used |
| F12 | Not Used |
| F13 | Not Used |
| F14 | Not Used |
| F15 | Transmission control module (stop/start) |
| F16 | Amplifier |
| F17 | Not Used |
| F18 | Video processing module |
| F19 | Power steering column |
| F20 | Body control module 6 |
| F21 | Body control module 4 |
| F22 | Body control module 7 |
| F23 | Electric steering column lock |
| F24 | Airbag |
| F25 | Data link connector |
| F26 | Not Used |
| F27 | Not Used |
| F28 | Not Used |
| F29 | Body control module 8 |
| F30 | Overhead console |
| F31 | Steering wheel control |
| F32 | Not Used |
| F33 | Heating ventilation/Air conditioning |
| F34 | Central gateway module (CGM) |
| F35 | Heated switch |
| F36 | Charger |
| F37 | Auxiliary power outlet – front |
| F38 | OnStar |
| F39 | Display |
| F40 | Obstacle detection |
| F41 | Body control module 1 (stop/start) |
| F42 | Radio |
| F43 | Auxiliary power outlet – console (circuit breaker) |
| F44 | Auxiliary power outlet – console |
| Relays | |
| K1 | Not Used |
| K2 | Retained accessory power |
| K3 | 2021: Content theft |
| K4 | Not Used |
| K5 | Not Used |
Engine compartment fuse block
Assignment of the fuses and relays in the engine compartment (2019, 2020, 2021)
| № | Usage |
|---|---|
| 3 | 2019-2020: Antilock brake system pump 2021: Electronic brake control module |
| 5 | 2019: Not Used 2020-2021: Trailer brake |
| 6 | Rear closure |
| 7 | Trailer stop/Turn LH |
| 8 | Memory seat module |
| 9 | Pedestrian friendly alert function |
| 10 | Semi-active damping system |
| 11 | 2019: DC-DC Battery 1 2020-2021: DC-DC Battery 1/2 |
| 12 | Rear defogger |
| 13 | Heated mirror |
| 14 | Not Used |
| 15 | Passive entry passive start |
| 16 | Front wiper |
| 17 | Passenger power seat |
| 18 | Power liftgate module |
| 19 | Driver power seat |
| 21 | Sunroof |
| 22 | Rear wiper |
| 23 | 2019: Auto headlamp leveling/Canister vent solenoid 2020-2021: Trailer interface module 2 |
| 26 | Transmission control module/Ignition |
| 27 | Instrument panel body/Ignition |
| 28 | Rear wiper |
| 29 | 2019: Seat ventilation 2020-2021: Trailer ignition |
| 30 | 2019-2020: Malfunction indicator lamp 2021: Malfunction indicator lamp start/stop Trailer interface module ignition |
| 32 | Rear drive control module 1 |
| 33 | 2019-2020: Front heated seat |
| 34 | Handsfree/Window switch |
| 35 | 2019: Not Used 2020-2021: Diesel exhaust fuel heater |
| 36 | Fuel module |
| 39 | Massage |
| 40 | Steering column lock |
| 41 | Not Used |
| 43 | Heated steering wheel |
| 44 | 2019: Not Used 2020: Seat ventilation 2021: Seat ventilation / Front heated seat |
| 46 | Engine control module/Ignition |
| 48 | Rear drive control module 2 |
| 49 | Heating ventilation/ Air conditioning blower motor |
| 50 | Not Used |
| 51 | Not Used |
| 54 | Not Used |
| 55 | Not Used |
| 56 | Starter motor |
| 57 | Not Used |
| 58 | Not Used |
| 59 | High-beam headlamps |
| 60 | 2019: Not Used 2020-2021: Trailer interface module 1 |
| 61 | Not Used |
| 62 | Not Used |
| 63 | Not Used |
| 65 | Air conditioning control |
| 67 | Not Used |
| 68 | Not Used |
| 69 | Not Used |
| 70 | Trailer park lamp |
| 72 | Starter pinion |
| 75 | Engine control module |
| 76 | Powertrain off engine |
| 78 | Horn |
| 79 | Washer pump |
| 81 | Transmission control module/Engine control module |
| 82 | 2019: Not Used 2020-2021: Nitrogen oxide sensor |
| 83 | Ignition coil |
| 84 | Powertrain on engine |
| 85 | Shunt |
| 86 | Shunt |
| 87 | 2019: Not Used 2020-2021: Diesel fuel heater 1 |
| 88 | Aeroshutter |
| 89 | 2019: Not Used 2020-2021: Selective catalytic reduction module |
| 92 | Trailer stop/Turn right |
| 93 | 2019: Not Used 2020-2021: Automatic headlamp leveling/Canister vent solenoid |
| 95 | 2019: Not Used 2020-2021: Smart sensors |
| 96 | 2019: Not Used 2020-2021: Diesel fuel heater 2 |
| 99 | Not Used |
| Relays | |
| 4 | Not Used |
| 20 | Rear defogger |
| 25 | Front wiper control |
| 31 | Run/Crank |
| 37 | Front wiper speed |
| 42 | Not Used |
| 64 | Starter motor |
| 66 | Powertrain |
| 71 | Trailer park lamp |
| 73 | Air conditioning control |
| 80 | Starter pinion |
| 90 | 2019: Not Used 2020-2021: Powertrain sensor |
| 94 | 2019: Not Used 2020-2021: Diesel exhaust fuel heater |
| 98 | 2019: Not Used 2020-2021: Diesel fuel heater |
2022
Instrument panel fuse block
Assignment of the fuses and relays in the instrument panel fuse box (2022)
| № | Usage |
|---|---|
| F1 | Left Power Window |
| F2 | Right Power Window |
| F3 | — |
| F4 | Direct Current to Direct Current Converter 2 |
| F5 | Auxiliary Power Outlet – Cargo |
| F6 | Heated Seat Battery 1 |
| F7 | Heated Seat Battery 2 |
| F8 | Body Control Module 3 – LED Headlamp Low Beam Right Control Signal, Right Front Turn Lamp Control Signal, Left Front Side Marker and Auxiliary Park, Left Rear Tail/Side Marker Control Signal, Left Daytime Running Lamps Control Signal |
| F9 | Electric Park Brake |
| F10 | Body Control Module 2 (Stop/Start) – Interior Lamps Control Signal, Door Handle Puddle Lamp (LED), Left Cornering Lamp, Right Cornering Lamp, Interior Lamps Control Signal, Backup Lamp Supply Voltage, License Plate Lamp Control Signal, Rear Closure Cargo Lamp Control Signal, Center High Mounted Stop Lamp LED Lamp Control Signal |
| F11 | — |
| F12 | — |
| F13 | — |
| F14 | — |
| F15 | Transmission Control Module (Stop/ Start) |
| F16 | Amplifier |
| F17 | |
| F18 | Video Processing Module |
| F19 | Power Steering Column |
| F20 | Body Control Module 6 – LED Backlight Control, Interior Lighting Inadvertent Load Control Signal, Fuel Door Lock Control Signal, LED Backlight Control Signal |
| F21 | Body Control Module 4 – LED Headlamp Low Beam Left Control Signal, Right Front Side Marker and Auxiliary Park, Right Rear Tail/ Side Marker Control Signal, Left Rear Stop Lamp Control Signal, Left Rear Stop/Turn Lamp Control Signal, Right DRL Control Signal |
| F22 | Body Control Module 7 – Right Rear Stop Lamp Control Signal, Right Rear Stop/ Turn Lamp Control Signal, Left Front Turn Lamp Control Signal, Right Rear Turn Control Signal |
| F23 | — |
| F24 | Airbag |
| F25 | Data Link Connector |
| F26 | — |
| F27 | — |
| F28 | — |
| F29 | Body Control Module 8 – Internal Driver/Fuel Door Unlock Relay Control Signal, Internal Non-Driver Door Lock Relay Control Signal, Internal All Door Unlock Relay Control Signal |
| F30 | Overhead Console |
| F31 | Steering Wheel Controls |
| F32 | — |
| F33 | Heating Ventilation and Air Conditioning Control Module |
| F34 | Central Gateway Module |
| F35 | Heated Seat Switch/Hazard Switch |
| F36 | Wireless Charger Module/USB Charge Port |
| F37 | — |
| F38 | OnStar |
| F39 | Shifter Interface Board/Center Stack/Head Up Display/ Instrument Panel Cluster/HVAC Display |
| F40 | Long Range Radar Sensor/ Ultrasonic Park Assist Module/Camera Module/External Object Calculating Module/ Side Blind Zone Alert Modules/Front Camera Module |
| F41 | Body Control Module 1 (Stop/Start) – LED Indicator Lighting Control, Accessory LED Control, Run-Start LED Control, Ambient Lighting LED Control 2, Liftgate Latch Motor Control Signal, Rear Wiper Control Signal, High Beam Lamp Control (Direct Drive), Rear Fog LED Lamp Control Signal, Windshield Washer Pump Motor Control Signal, Run/Crank Relay Control Signal, ECM/TCM ACC Wakeup Control Signal, Left Rear Turn Control Signal, Rear Wiper Wash Pump Control Signal, Brake Pedal Apply Signal |
| F42 | Radio |
| F43 | Console Auxiliary Power Outlet (Circuit Breaker) |
| F44 | Front Console Auxiliary Power Outlet |
| Relay | |
| K1 | — |
| K2 | Retained Accessory Power |
| K3 | — |
| K4 | — |
| K5 | — |
Engine compartment fuse block
Assignment of the fuses and relays in the engine compartment fuse box (2022)
| № | Usage |
|---|---|
| 3 | Electronic Brake Control Module |
| 5 | Not Used |
| 6 | Spare |
| 7 | Left Trailer Stop/Turn Lamp |
| 8 | Memory Seat Module, Driver and Passenger |
| 9 | — |
| 10 | Semi-active Damping System/Spare |
| 11 | Direct Current to Direct Current Converter 1 |
| 12 | Rear Window Defogger |
| 13 | Outside Rear View Mirrors Defogger |
| 14 | — |
| 15 | Passive Entry Passive Start Module |
| 16 | Front Wiper |
| 17 | Passenger Power Seat |
| 18 | Power Liftgate |
| 19 | Driver Power Seat/ Memory Seat Module/ Driver Seat Massage Control |
| 21 | Power Sunroof |
| 22 | — |
| 23 | — |
| 26 | Transmission Control Module/Ignition |
| 27 | Inside Rear View Mirror, Shifter Interface Board Module Run/Crank, Central Gateway Module Run/Crank, Heating Ventilation and Air Conditioning Control Module Run/Crank ignition 3 |
| 28 | Rear Wiper |
| 29 | — |
| 30 | Fuel Tank Zone Module Run/Crank, Direct Current to Direct Current Transformer Run/Crank, Electronic Brake Control Module Run/Crank, Instrument Panel Cluster Run/Crank |
| 32 | Rear Drive Control Module 1 |
| 33 | Front Heated Seat Power 2 |
| 34 | Liftgate Module / Front Window Switches |
| 35 | — |
| 36 | Fuel Tank Zone Module |
| 39 | Driver Seat Massage / Passenger Seat Massage |
| 40 | — |
| 41 | — |
| 43 | Heated Steering Wheel |
| 44 | Front Heated Seat Power Feed 1 / Front Vented Seats/ Rear Heated Seats |
| 46 | Engine Control Module Ignition |
| 48 | Rear Drive Control Module 2 |
| 49 | Heating Ventilation and Air Conditioning Control Blower Motor |
| 50 | Spare |
| 51 | Spare |
| 54 | Spare |
| 55 | Spare |
| 56 | Starter Motor |
| 57 | — |
| 58 | — |
| 59 | High Beam Headlamps |
| 60 | — |
| 61 | Spare |
| 62 | Spare |
| 63 | Spare |
| 65 | Air Conditioning Clutch |
| 67 | Spare |
| 68 | Spare |
| 69 | — |
| 70 | Trailer Park Lamp |
| — | |
| 72 | Starter Pinion |
| 75 | Engine Control Module Main |
| 76 | Powertrain Off Engine, Engine Control Module Power Train Ignition 1 |
| 78 | Horn |
| 79 | Front and Rear Washer Pump |
| 81 | Engine Control Module Battery/Spare |
| 82 | — |
| 83 | Ignition Coils |
| 84 | Canister Purge Solenoid / Step Cam Exhaust Solenoid Cylinder 2 and 3 / Step Cam Intake Cylinder Solenoids / Turbo Bypass Solenoid / Oxygen Sensor (Pre) / O2 Heater / Oxygen Heated Sensor / Mass Airflow / Inlet Air Temperature / Throttle Inlet Absolute Pressure / Coolant Flow Control Valve |
| 85 | Shunt |
| 86 | Shunt |
| 87 | — |
| 88 | Aeroshutter |
| 89 | — |
| 92 | — |
| 93 | Canister Vent Solenoid |
| 95 | — |
| 96 | — |
| 99 | — |
| Relays | |
| 20 | Rear Defogger / Outside Rear View Mirrors Defogger |
| 25 | Front Wiper Control |
| 31 | Run/ Crank |
| 37 | Front Wiper Speed |
| 42 | — |
| 64 | STRTR MTR, |
| 66 | Powertrain |
| 71 | Trailer Park Lamps |
| 73 | Air Conditioning Controls |
| 80 | Starter Pinion |
| 90 | — |
| 94 | — |
| 98 | — |
Conclusion
For owners and enthusiasts of classic Cadillac XT4 2019-2022, 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 Cadillac’s craftsmanship and innovation in the automotive industry during that era.
