2026 Cadillac CT4 Fuses and Fuse Box User Guide

2026 Cadillac CT4 Fuses and Fuse Box User Guide

This blog covers 2026 Cadillac CT4 fuses and fuse box. Understand the placement, layout, and purpose of each fuse to diagnose electrical issues and keep your car running smoothly.

Video: 2026 Cadillac CT4 Fuses 

Cadillac Electrical System Guide

Electrical System Overload
The vehicle has fuses and circuit breakers to protect against an electrical system overload.

When the current electrical load is too heavy, the circuit breaker opens and closes, protecting the circuit until the current load returns to normal or the problem is fixed. This greatly reduces the chance of circuit overload and fire caused by electrical problems.

Fuses and circuit breakers protect power devices in the vehicle.

If there is a problem on the road and a fuse needs to be replaced, the same amperage fuse can be borrowed. Choose some feature of the vehicle that is not needed to use and replace it as soon as possible.

To check a fuse, look at the band inside the fuse. If the band is broken or melted, replace the fuse. Be sure to replace a bad fuse with a fuse of the identical size and rating.

Replacing a Blown Fuse

1. Turn off the ignition.
2. Locate the fuse puller in the engine compartment fuse block. 
3. Use the fuse puller to remove the fuse from the top or side, as shown above.
4. If the fuse must be replaced immediately, borrow a replacement fuse with the same amperage from the fuse block. Choose a vehicle feature that is not needed to safely operate the vehicle. Repeat Steps 2-3.
5. Insert the replacement fuse into the empty slot of the blown fuse.

At the next opportunity, see your dealer to replace the blown fuse.

Headlamp Wiring
An electrical overload may cause the lamps to go on and off, or in some cases to remain off. Have the headlamp wiring checked right away if the lamps go on and off or remain off.

Windshield Wipers
If the wiper motor overheats due to heavy snow or ice, the windshield wipers will stop. Wiper function is available immediately after the wiper switch is set to off, and back to on.

To protect the wiper motor from overheating, the wipers may slow down when the windshield is dry for a long period of time. If a period of dry operation, or little moisture, exceeds 10 minutes, the wipers may switch to intermittent operation, and remain there.

When moisture is again detected on the windshield, wiper operation will return to the operator selected speed.

Although the circuit is protected from electrical overload, overload due to heavy snow or ice may cause wiper linkage damage. Always clear ice and heavy snow from the windshield before using the windshield wipers.

If the overload is caused by an electrical problem and not snow or ice, be sure to get it fixed.

Fuses and Circuit Breakers
The wiring circuits in the vehicle are protected from short circuits by a combination of fuses and circuit breakers. This greatly reduces the chance of damage caused by electrical problems.

Danger
Fuses and circuit breakers are marked with their ampere rating. Do not exceed the specified amperage rating when replacing fuses and circuit breakers. Use of an oversized fuse or circuit breaker can result in a vehicle fire. You and others could be seriously injured or killed.

Warning
Installation or use of fuses that do not meet GM’s original fuse specifications is dangerous. The fuses could fail, and result in a fire. You or others could be injured or killed, and the vehicle could be damaged.

Engine Compartment Fuse Block

The engine compartment fuse block is on the driver’s side of the engine compartment.

Lift the fuse block cover to access the fuses.
The vehicle may not be equipped with all of the fuses and relays shown.

Caution
Spilling liquid on any electrical component on the vehicle may damage it. Always keep the covers on any electrical component.

uses	Usage
1	Long Range Radar Front Sensor
2	Park/Daytime Running Lamps
3	Exterior Lighting Module 4
4	Exterior Lighting Module 7
5	Headlamp Level
6	–
7	Electronic Brake Control Module
8	Washer Pump
9	–
10	–
11	–
12	Horn
13	Front Wiper
14	Exterior Lighting Module 6
15	Exterior Lighting Module 1
16	Exterior Lighting Module 5
17	Exterior Lighting Module 3
18	Aero Shutter
19	–
20	–
21	Virtual Key System/ Power Sounder Module
22	Engine Control Module Battery
23	Transmission Control Module
24	Active Engine Mount
25	–
26	Engine Control Module
27	Injectors/Ignition 2
28	Charged Air Cooler/ Not Used
29	Transmission Aux Oil Pump/Transmission Reverse Lock Out
30	Injectors/Ignition 1
31	Emissions 1
32	Emissions 2
33	Starter Solenoid
34	–
35	–
36	Starter Pinion/Not Used
37	AC Clutch
38	–
39	–
40	–
41	–
42	Water Pump/Not Used
43	–
44	–

 

Relays	Usage
47	–
48	Front Wiper Speed/ Not Used
49	Front Wiper Control
51	–
52	Engine Control Module
53	Starter Solenoid
54	Starter Pinion/Not Used
55	–
57	AC Clutch

Instrument Panel Fuse Block

The instrument panel fuse block is in the end of the driver side of the instrument panel.

To access the fuses, remove the end panel by gently prying with a plastic tool near each clip, beginning at the point shown.

To install the end cover, insert the tabs on the back of the cover into the slots in the instrument panel at the points shown. Align the clips with the slots in the instrument panel, and press the cover into place.

The vehicle may not be equipped with all of the fuses and relays shown.

Fuses	Usage
1	–
2	Heating, Ventilation, and Air Conditioning Blower
3	–
4	–
5	Theft Deterrent/Universal Garage Door Opener/ Overhead Console/Rain Sensor
6	–
7	Air Quality Ionizer
8	Heated Steering Wheel
9	–
10	Electronic Steering Column Lock 1
11	–
12	–
13	–
14	–
15	–
16	–
17	–
18	Display/Infotainment/ USB/Multi-function Control Module
19	Sensing and Diagnostic Module/Automatic Occupant Sensing/Data Link Connection/Wireless Charging Module/Virtual Key Module
20	Power Steering Column Module/Electronic Steering Column Lock 2
21	Driver Monitor System/ Performance Data Recorder
22	–
23	–
24	–
25	USB
26	–
27	–
28	–
29	–
30	–
31	Headlamp Level/Spare
32	–
33	Body Ignition/IP Ignition
34	Exhaust Valve
35	Transmission Control Module Ignition/Engine Control Module Ignition/ Shift Ignition/Brake Ignition
36	Shift Module
37	Body Control Module 1/ Electronic Park Brake Switch
38	Center Stack Module
39	Steering Wheel Controls
40	Body Control Module 2
41	Body Control Module 3
42	Body Control Module 4

 

Circuit Breakers	Usage
CB1	Auxiliary Power Outlet 1
CB2	Auxiliary Power Outlet 2

 

Relays	Usage
1	Run After Park/Accessory
2	Run Crank
3	–
4	–
5	–

Rear Compartment Fuse Block

The rear compartment fuse block is behind a cover on the driver side of the rear compartment.

The vehicle may not be equipped with all of the fuses, relays, and features shown.

Fuses	Usage
1	Remote Function Actuator
2	–
3	Driver Heated Seat
4	Fuel Tank Zone Module
5	–
6	–
7	–
8	–
9	–
10	Motor Seat Belt Passenger
11	Canister Vent Solenoid
12	Sunroof
13	–
14	–
15	Passenger Heated Seat
16	–
17	Electronic Suspension Control
18	–
19	Motor Seat Belt Driver
20	Rear Defog
21	DC to DC Transformer 2
22	Driver Power Window/ Door Handle Switch
23	External Object Calculating Module/Front Camera Module/High Definition Localization Module/Short Range Radar
24	Passenger Power Window/Door Handle Switch
25	–
26	Amplifier (V Series Blackwing)
27	Rear Drive Control Module
28	–
29	–
30	–
31	DC to DC Transformer 1
32	Transfer Case Electronic Control
33	Central Gateway Module/Side Blind Zone Alert
34	Video Processing Module
35	Hands-Free Closure Release
36	Exterior Lighting Module 2
37	Passenger Memory Seat Module
38	–
39	Right Front/Right Rear Window
40	–
41	–
42	Amplifier
43	Park Assist Module
44	Driver Memory Seat Module
45	OnStar
46	–
47	–
48	–
49	–
50	Driver Seat
51	Left Front/Left Rear Window
52	Passenger Seat

 

Relays	Usage
53	–
54	–
55	Run

How to replace the Fuse of the 2026 Cadillac CT4

To replace a fuse in your 2026 Cadillac CT4, follow these steps:

Materials:

1. The new fuse of the correct amperage.
2. Fuse puller or needle-nose pliers.

Step-by-Step Fuse Replacement Guide

1. Identify the Fuse Box
   1. Engine compartment (Power Distribution Center): Located under the hood, typically near the battery.
   2. Passenger cabin fuse box: Mounted on the driver’s side end of the instrument panel, exposed when the driver-side door is open
2. Determine Which Fuse to Replace

   1. Check the diagram printed on the fuse box cover.

   2. Locate the specific fuse for the component that’s malfunctioning (e.g., interior lights, radio).

   3. Note the fuse’s location and amp rating (e.g. 10 A, 20 A).

3. Remove the Fuse Cover & Fuse

   1. Carefully lift off the fuse box cover—there’s often a diagram printed inside it.

   2. Use the built-in fuse puller (usually clipped inside the cover) or needle-nose pliers to extract the blown fuse.

   3. Inspect the fuse—if the internal metal strip is broken or burnt, it needs replacement.

4. Install the New Fuse

   1. Match the replacement fuse to the same amp rating as the original.

   2. Press it firmly into the correct slot until fully seated.

   3. Double‑check it aligns securely and sits flush with the surrounding fuses.

5. Test & Reassemble

   1. Turn the ignition or start the engine.

   2. Check if the previously non‑functional component is working properly.

   3. Close the fuse box by snapping the cover back into place securely.

Tips:
Always use a fuse with the correct amperage rating to prevent electrical issues or damage to the vehicle.

Useful Links:

2024 Cadillac CT4 V-SERIES Specs, Price, Features, Mileage and Review

2026 Cadillac CT4 Maintenance Schedule User Guide

2026 Cadillac CT4 Engine Oil and Fluid User Guide