2020 GM Duramax 3500 with factory tow prep

**screamineagle** · 04-23-2020, 08:34 AM

Good morning, I bought a new momentum 395 at thanksgiving last year. parked it and tried to hook it up a few weeks ago for test run on the new 2020 Chevy.
I cannot get the truck to recognize the new trailer. It was doing funky things directional flashing too fast or not working at all. Message telling me their was a brake system problem. Any ideas?

**KamFlyer** · 04-23-2020, 02:01 PM

Originally Posted by screamineagle

Good morning, I bought a new momentum 395 at thanksgiving last year. parked it and tried to hook it up a few weeks ago for test run on the new 2020 Chevy.
I cannot get the truck to recognize the new trailer. It was doing funky things directional flashing too fast or not working at all. Message telling me their was a brake system problem. Any ideas?

I would start with the ground connection between the trailer 7 way plug and the trailer chassis. Typically trailer running lights use the chassis as the return path. New trucks with the integrated brake controllers also tend to be quite finicky about poor electrical connections.

**Gotime4** · 04-23-2020, 02:03 PM

Off topic, did you get a SRW or DRW?

**KamFlyer** · 04-23-2020, 02:07 PM

Originally Posted by Gotime4

Off topic, did you get a SRW or DRW?

Ours is a 2017 GMC DRW.

**Redapple63** · 04-23-2020, 08:01 PM

Definitely an electrical issue. As was pointed out check the 7 pin on both the truck and trailer sidecar wired correctly.

**traveldawg** · 04-24-2020, 09:06 AM

A buddy of mine had the same issue. He had to use something like this... https://www.etrailer.com/Accessories.../T4845900.html

Do you have disc brakes? it seems to happen more often with those than with standard drum brakes.

GM owners of the 2014 vintage range had to use them. Then they got fixed around 2016 or 2017. i guess the let that engineer go and the new engineer went back to the old ways????

**tomato** · 04-24-2020, 05:57 PM

I have a 2020 as well, and these trucks do not like to have the trailer plugged in while running or still powered. Need to turn the truck off and let it go to sleep (2 minutes I believe) before plugging in...PITA...

**screamineagle** · 04-27-2020, 04:36 AM

Thanks, that sounds like its a PITA but if it works.
Its funny, the dealer spent 3 hours on this when we took delivery but I am not sure what the truck status was. All I know is when I drive it seems like it starts working. Do you have the camera system in yours?

**tomato** · 04-27-2020, 08:20 AM

Originally Posted by screamineagle

Thanks, that sounds like its a PITA but if it works.
Its funny, the dealer spent 3 hours on this when we took delivery but I am not sure what the truck status was. All I know is when I drive it seems like it starts working. Do you have the camera system in yours?

I have the camera system but not the invisible trailer setup (5th wheel is too long). The lights, cameras (side view, turn signal operated ones) and TPMS sensors do funky things if plugged in when running.

**screamineagle** · 04-27-2020, 08:42 AM

OK, I have the same thing. When I am towing and turn right it shows the right side of the trailer when I am turning left the screen is black. does your do the same.