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2025 Cadillac OPTIQ
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Always the correct part
We know our products
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Factory (OEM) tow package required for installation
Warranty: One-Year Limited Warranty
Electrical System Type: 2W
Output Type: 4-Way Flat
Installation Difficulty: Novice
Installation Time Exact (Minutes): 5
CURT custom wiring connectors are the easiest way to outfit your vehicle with a CURT trailer wiring connection. They are built with some of the most advanced technology in the industry, and each one is custom-fitted to work with a specific make and model. Some automotive manufacturers install a special socket on the vehicle to be used for vehicle-to-trailer wiring. Although this special socket is not equipped on every vehicle, a CURT custom wiring connector -- also called a T-connector -- utilizes the socket for simple, stress-free installation. Rather than requiring you to cut, splice and solder into your vehicle's wiring system, the custom wiring connector uses a single OEM-compatible plug and instantly provides a standard, universal vehicle-to-trailer wiring connection, typically in the form a 4-way flat. All CURT custom wiring connectors are made vehicle-specific for the easiest possible installation and the best fit. This particular plug-in connector provides a 4-way flat socket and is designed to be a custom wiring option for certain years of the Cadillac XT4, Lyriq, Chevrolet Blazer EV, and Equinox EV (to verify your vehicle compatibility, see application info). It comes with all necessary hardware to establish a solid connection. It also comes with a dust cover to keep the connector socket clean when not in use. To ensure long-lasting reliability, all CURT custom wiring connectors are thoroughly tested for optimal functionality. Stress is the last thing you should feel when towing a trailer -- whether you're hauling your RV to that favorite camping destination, your ATVs up to the hunting grounds or your fishing boat to the new hidden hotspot. At CURT, we think your towing equipment should add to the enjoyment of your experience, not detract from it.
CURT offers a variety of high-quality trailer hitches and accessories for select vehicle models. Find the perfect fit for your towing needs at TowUniverse.
CURT, a Lippert brand, offers a complete line of towing products and is the leading manufacturer of custom-fit trailer hitches. We offer the broadest selection of custom-fit hitches, and each one is designed, welded, and coated in Wisconsin.
CURT is also a leader in flat towing products, as well as 5th wheel, gooseneck, and weight distribution hitches, ball mounts, electrical components, cargo solutions, and other towing accessories.
For everything from passenger cars and vans to full-size pickups and SUVs, CURT is 'The First Name in Towing Products®.'
Experts available to answer your questions
Call 888-634-9494Rediscover "Us" Time | Tested. Proven. Safe. Towing Products
6 compatible vehicles
| Year | Make & Model | Notes |
|---|---|---|
| 2023 - 2026 | Cadillac LYRIQ | Installation Time: 30-60 minutes |
| 2025 | Cadillac OPTIQ | — |
| 2019 - 2025 | Cadillac XT4 | Installation Time: 30-60 minutes |
| 2024 - 2026 | Chevrolet Blazer EV | Installation time: 30-60 minutes |
| 2024 - 2026 | Chevrolet Equinox EV | Installation time: 30-60 minutes |
| 2024 - 2026 | Honda Prologue | Installation time: 30-60 minutes |
The CURT Custom 4-Flat, Select Cadillac XT4, Requires Dealer Activation of Plug (Part #BKDK56427) fits 2023-2026 Cadillac LYRIQ models. The 2026 model year is the last year covered by this part number. For newer models, check for an updated version.
The CURT Custom 4-Flat, Select Cadillac XT4, Requires Dealer Activation of Plug (Part #BKDK56427) fits the following vehicles: 2023-2026 Cadillac LYRIQ; 2025 Cadillac OPTIQ; 2019-2025 Cadillac XT4; 2024-2026 Chevrolet Blazer EV; 2024-2026 Chevrolet Equinox EV; 2024-2026 Honda Prologue. Always verify your specific year, make, and model before ordering.
Yes, the CURT Custom 4-Flat, Select Cadillac XT4, Requires Dealer Activation of Plug (Part #BKDK56427) is designed to fit the 2023-2026 Cadillac LYRIQ.
The CURT Custom 4-Flat, Select Cadillac XT4, Requires Dealer Activation of Plug (Part #BKDK56427) Typical installation time is 30-60 minutes. Basic hand tools are typically all you need.
Yes, CURT part 56427 is designed for the Cadillac XT4. Installation requires disconnecting the negative battery terminal before beginning work.
Yes, CURT part 56427 is designed for the Cadillac Lyriq. The installation procedure differs from the XT4; the vehicle must be turned off but the battery does not need to be disconnected.
Yes, CURT part 56427 is designed for the Chevy Blazer, including the Blazer EV. The installation procedure differs from the XT4; the vehicle must be turned off but the battery does not need to be disconnected.
You will need a ratchet or wrench and a cutting tool. For Cadillac Lyriq and Chevy Blazer models, you will also need a 7mm socket (for Blazer EV) or T-15 Torx bit (for Lyriq) and a trim tool.
Yes. For the Cadillac XT4, you must locate the vehicle battery (refer to your vehicle owner's manual for location), disconnect the negative battery terminal, and fasten this wire down and away from the battery during installation.
No. For the Cadillac Lyriq and Chevy Blazer, you do not need to disconnect the battery. Simply ensure the vehicle is turned off before beginning installation.
1. Disconnect the negative battery terminal and fasten it away from the battery. 2. From under the rear bumper cover, locate the housing with dust cover. 3. Slide the red lock back, press the housing lock in, and remove the dust cover. 4. Install the custom wiring harness and slide the red lock back into the locked position. 5. Zip tie the harness as needed with the 4-flat mounted near the receiver hitch. 6. Test the harness with a test light, 4-flat tester, or functioning trailer. 7. Reinstall all removed items and reconnect the negative battery terminal. 8. Install the provided 4-flat dust cover.
1. Ensure the vehicle is turned off. 2. From under the rear bumper, locate the plastic facias. 3. Remove the facias using a 7mm socket (Blazer EV) or T-15 Torx bit (Lyriq). Remove all 16 screws and use a trim tool to remove 2 push fasteners. 4. On the passenger side, locate the backup alarm. Just above and to the rear of the backup alarm, find the black connector with white filler blocks. Locate the red tab, push it towards the white filler blocks, and press the housing release to remove the dust cover. 5. Install the custom wiring harness and slide the red lock back into the locked position. 6. Zip tie the harness as needed with the 4-flat mounted near the receiver hitch. 7. Test the harness with a test light, 4-flat tester, or functioning trailer. 8. Reinstall all removed items and install the provided 4-flat dust cover.
From under the vehicle rear bumper, locate the plastic facias. For Chevy Blazer EV, use a 7mm socket to remove the fasteners. For Cadillac Lyriq, use a T-15 Torx bit. Remove all 16 screws and use a trim tool to remove 2 push fasteners.
On the passenger side, locate the backup alarm. Just above and to the rear of the backup alarm, there is a black connector with white filler blocks protruding. Locate the red tab and push it towards the white filler blocks, then press the housing release to remove the dust cover.
Slide the red lock back, press the housing lock in, and remove the dust cover. Install the custom wiring harness into the connector and slide the red lock back into the locked position.
Zip tie the harness as needed with the 4-flat mounted near the receiver hitch. This secures the harness and prevents movement.
Once the harness is connected, verify that it is functioning by attaching the battery (if disconnected) and testing with a test light, 4-flat tester, or a functioning trailer. This confirms proper operation before final reassembly.
Reinstall all items removed during installation. If the negative battery terminal was disconnected at the beginning (XT4 only), reconnect it. Install the provided 4-flat dust cover to help prevent corrosion.
Periodic inspection of all wires and connections should be performed to ensure there is no visible damage or loose connections.
Do not exceed the product rating or tow vehicle lamp load rating, whichever is lower. Refer to the product documentation or contact CURT for the specific rating.
Do not lay tools across the positive terminal (typically labeled with red covers or a red '+' symbol). This can cause a ground short, resulting in sparks and/or electrical shocks.
CURT part 56427 fits the Cadillac XT4, Cadillac Lyriq, and Chevy Blazer (including Blazer EV).
You will need a ratchet or wrench and a cutting tool. For Lyriq and Blazer models, also a 7mm socket (Blazer EV) or T-15 Torx bit (Lyriq) and a trim tool.
Battery disconnection is required for Cadillac XT4 only. For Cadillac Lyriq and Chevy Blazer, simply turn off the vehicle.
The manual does not mention drilling as a required step for any supported vehicle model.
Do not exceed the product rating or tow vehicle lamp load rating, whichever is lower. Do not lay tools across the positive battery terminal to avoid shorts and electrical shocks.
Total for 4 items:
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