Cadillac CT4 (2020-2021) – fuse and relay box
The cigarette lighter fuses (power receptacles) on the Cadillac CT4 are the CB1 and CB2 switches in the instrument panel fuse box.
Passenger compartment
The instrument panel fuse block is located on the driver’s end of the instrument panel. To access, remove the end cover by gently prying with a plastic tool near each clamp, starting from the point shown.
To install a cover, insert the tabs on the back of the cover into the slots on the dashboard. Align the clips with the holes in the instrument panel and snap the cover into place.
Arrangement of fuses in the instrument panel
| Number | Description |
|---|---|
| 1 | Not used |
| 2 | HVAC blower |
| 3 | Not used |
| 4 | Not used |
| 5 | Anti-theft alarm;
Universal garage door opener. |
| 6 | Not used |
| 7 | Air quality ionizer |
| 8 | Heated steering wheel |
| 9 | Not used |
| 10 | Electronic steering column lock 1 |
| 11 | Not used |
| 12 | Not used |
| 13 | Not used |
| 14 | Not used |
| 15 | Not used |
| 16 | Not used |
| 17 | Not used |
| 18 | Display;
Infotainment; USB; CSM. |
| 19 | Airbag;
Automatic detection of passengers; Data link connection; Wireless charging module. |
| 20 | Power steering column module;
Electronic steering column lock 2. |
| 21 | Not used |
| 22 | Not used |
| 23 | Not used |
| 24 | Not used |
| 25 | USB |
| 26 | Not used |
| 27 | Not used |
| 28 | Not used |
| 29 | Not used |
| 30 | Not used |
| 31 | Headlight level |
| 32 | Not used |
| 33 | Body ignition;
IP ignition. |
| 34 | Exhaust valve |
| 35 | Transmission control module ignition;
Engine control module ignition; Gear shift ignition; Brake ignition. |
| 36 | Offset module |
| 37 | Body control module 1;
Electronic parking brake switch. |
| 38 | Middle panel module |
| 39 | Steering wheel controls |
| 40 | Body control module 2 |
| 41 | Body control module 3 |
| 42 | Body control module 4 |
| CB1 | Auxiliary power socket 1 (switch) |
| CB2 | Auxiliary power socket 2 (switch) |
| Relays | |
| 1 | “Run after park”
Accessories |
| 2 | Run / start relay |
| 3 | Not used |
| 4 | Not used |
| 5 | Not used |
Engine compartment
The engine compartment fuse block is located on the driver’s side in the engine compartment. Lift the cover to access the fuses.
Arrangement of fuses and relays in the engine compartment
| Number | Description |
|---|---|
| 1 | Front long range radar sensor |
| 2 | Parking / daytime running lamps |
| 3 | Outdoor lighting module 4 |
| 4 | Outdoor lighting module 7 |
| 5 | Headlamp leveling |
| 6 | Not used |
| 7 | Electronic brake control module |
| 8 | Washer pump |
| 9 | Not used |
| 10 | Not used |
| 11 | Not used |
| 12 | Horn |
| 13 | Front wiper |
| 14 | Outdoor lighting module 6 |
| 15 | Outdoor lighting module 1 |
| 16 | Outdoor lighting module 5 |
| 17 | Outdoor lighting module 3 |
| 18 | Aero shutter |
| 19 | Not used |
| 20 | Not used |
| 21 | Virtual key system;
Acoustic signaling module. |
| 22 | Engine control module |
| 23 | Transmission control module;
Gearbox reverse lock. |
| 24 | Active engine mount |
| 25 | Not used |
| 26 | Engine control module |
| 27 | Injectors / Ignition 2 |
| 28 | Charge air cooler |
| 29 | Auxiliary gearbox oil pump;
Gearbox reverse lock. |
| 30 | Injectors / Ignition 1 |
| 31 | Emissions 1 |
| 32 | Emissions 2 |
| 33 | Starter solenoid |
| 34 | Not used |
| 35 | Not used |
| 36 | Starter gear |
| 37 | Air conditioning clutch |
| 38 | Not used |
| 39 | Not used |
| 40 | Not used |
| 41 | Not used |
| 42 | The water pump |
| 43 | Not used |
| 44 | Not used |
| Relays | |
| 47 | Not used |
| 48 | Front wiper speed |
| 49 | Front wiper control |
| 51 | – |
| 52 | Engine control module |
| 53 | Starter solenoid |
| 54 | Starter gear |
| 55 | Not used |
| 57 | Air conditioning clutch |
| 58 | Not used |
Trunk
The fuse block in the rear compartment is located behind the driver’s side cover in the rear compartment.
Arrangement of fuses and relays in the luggage compartment
| Number | Description |
|---|---|
| 1 | Remote function actuator |
| 2 | Not used |
| 3 | Heated driver’s seat |
| 4 | Fuel tank zone module |
| 5 | Not used |
| 6 | Not used |
| 7 | Not used |
| 8 | Not used |
| 9 | Not used |
| 10 | Motor seat belt passenger |
| 11 | Canister vent solenoid valve |
| 12 | Sunroof |
| 13 | Not used |
| 14 | Not used |
| 15 | Heated passenger seat |
| 16 | Not used |
| 17 | Electronic suspension control |
| 18 | Not used |
| 19 | Motor seat belt driver |
| twenty | Rear demisting |
| 21 | DC-DC transformer 2 |
| 22 | Driver’s window door lock switch |
| 23 | External module for calculating objects;
Front camera module; High definition localization; Short-range radar. |
| 24 | Passenger window door lock switch |
| 25 | Not used |
| 26 | Amplifier (V series) |
| 27 | Rear drive control module |
| 28 | Not used |
| 29 | Not used |
| thirty | Not used |
| 31 | DC-DC transformer 1 |
| 32 | Electronic transfer case control |
| 33 | Central gate module;
Side blind spot alarm. |
| 34 | Video processing module |
| 35 | Hands-free closure release |
| 36 | Outdoor lighting module 2 |
| 37 | Passenger seat module with memory |
| 38 | Not used |
| 39 | Right front / right rear window |
| 40 | Not used |
| 41 | Not used |
| 42 | Amplifier |
| 43 | Parking assist module |
| 44 | Driver memory module |
| 45 | OnStar |
| 46 | Not used |
| 47 | Not used |
| 48 | Not used |
| 49 | Not used |
| 50 | Driver’s seat |
| 51 | Left front and left rear windows |
| 52 | Passenger seat |
| Relays | |
| 53 | Not used |
| 54 | Not used |
| 55 | Start relay |
