How To Fix Check Trailer Rear Lamp Message On 2022 Chevy/GMC with Tailgate Light Bar

Updated 11/11/2024 | Published 06/25/2022

Products Featured in This Question

7-Way RV to 4-Way Flat Trailer Connector Adapter

(125)

$20.57

Load Resistor Kit for LED Turn Signals - 50 Watts - 6 Ohm - Qty 2

(36)

$8.92

Question:

Hooked a light bar under the tailgate used the T- connector 7 pin to 4 pin , to trailer tow package.All connected works great But every time you press on the brakes, it says- Check Trailer Rear Lamp- and goes away when you release the brake on the instrument panel.

asked by: Victor B

Expert Reply:

I do have an option for you but this due to the internal computers and programs on the truck which can't be bypassed. That said, you can trick them and for this I recommend purchasing an adapter like the 7-Way RV to 4-Way Flat Trailer Connector Adapter part # HM47365 and then using load resistors like the LED Load Resistor Kit part # DI34ZR. This will simulate a full load on the truck tail light circuits.

expert reply by: Conner L

Matt T.

11/10/2024

Ca. Warranty or something do something to the computer to stop it? I have the same issue. Seems like it start on a rainy day

Kevin C.

11/11/2024

@MattT No, the truck system is designed to sense for that specific signal and since LED lights require less power they can't trigger the sensor without adding in load resistors. It would require GM to use a different signal to sense the trailer or add in some kind of parameter to the system to sense the lower amperage of the LED lights.