Solution for 2020 GM Truck that Won't Recognize Trailer Wiring Connection

Updated 05/06/2026 | Published 03/21/2022

Question:

We have a 2020 chevy pickup 2500. Our truck disnt recognize our trailer when hooked up so lights dont work. The chip in new gm trucks dont recognize a trailer if it is under .55 ma. Our trailer is only .50ma so the truck dosnt recognize it. Dealer and gm manufacturer wont do anything. Lots of complaints on sites about this problem with gm trucks. Do you have any thing that can help? Please

asked by: Jeanne A

Expert Reply:

What you need is more resistance on your trailer wiring circuits so that your truck thinks a trailer is connected. So what you could do is install the load resistors part # DI34ZR on two of your trailer wiring circuits and your truck would draw more amperage when connected and you'd be good.

expert reply by: Jameson C

Terry D.

12/31/2025

I used the exact connectors listed and no change in symptoms - 2019 Cheverolet Silverado 1500 - truck still does not recognize that the trailer is hooked up.

Jameson C.

12/31/2025

@TerryD Have you been able to try connecting to a trailer that has incandescent bulbs to see if it shows a connection at that point?

Zack

5/6/2026

Tried adding the resistors and no luck. Tried hooking up to 3 other trailers and they all work (some with LED) just fine with my truck. The trailer is brand new and we hooked it up to our neighbors truck and the new trailer works perfectly fine with the other truck.

Jameson C.

5/6/2026

@Zack does new trailer have all LED taillights?

Zack

5/6/2026

@JamesonC yes. Wife just told me to do a manual brake module reset with the brake pedal and that seemed to get it to work for now. Will have to retest the other trailers tomorrow.