"Check Trailer Wiring"

[Precise_One]

While returning from a week long trip from BC, we experienced our truck indicating Check Trailer Wiring on dash info centre. It then indicates trailer is connected and will go back and forth with these messages and annoying dinging sound. I have tried plugging the trailer into the factory plug on the bumper and still have the same issue. All lights and brakes seem to be working fine. Looked over exposed wiring and can see no obvious signs of problems. Our truck is a 2015 GMC 3500 srw, Duramax and our trailer is a 2015 Wildcat 312BHX. This is our third season with the trailer and second with the truck. Anyone experience this problem?
Thanks

[Toolguy5]

Precise One wrote:
While returning from a week long trip from BC, we experienced our truck indicating Check Trailer Wiring on dash info centre. It then indicates trailer is connected and will go back and forth with these messages and annoying dinging sound. I have tried plugging the trailer into the factory plug on the bumper and still have the same issue. All lights and brakes seem to be working fine. Looked over exposed wiring and can see no obvious signs of problems. Our truck is a 2015 GMC 3500 srw, Duramax and our trailer is a 2015 Wildcat 312BHX. This is our third season with the trailer and second with the truck. Anyone experience this problem?
Thanks

I have a 2015 3500 HD Denali same issue last year. Replace the trailer cord we are currently on a 3 month trip with 3000 miles of towing behind us and no issues.

[allen8106]

dahkota wrote:
When we had a tt/truck we had the same problem somewhere in Montana. Cleaned the dust and dirt out of the plug and the problem stopped.

Caig DeoxIT Contact and Connector Treatment.

[Crodad]

agesilaus wrote:
On my truck the problem was in the plug from the trailer. I bought a new plug and wired it in and that fixed the problem. Amazon

X2 same here. Changed the plug and problem solved.

[Ron_Nielson]

If you have a GM truck and the DIC message is exactly, CHECK TRAILER WIRING, don't bother to look at the truck. Look at the trailer wiring. The ITBC system is quite precise in determining this.

Check Trailer Wiring Message on the DIC

Some customers may experience an intermittent Check Trailer Wiring message in vehicles equipped with ITBC (Integrated Trailer Brake Controller) with no DTC stored. This message may be displayed each time the trailer's running lamps, turn signal lamps or brake lamps turn on - especially if the trailer is equipped with a large number of lamp loads.


This condition is caused by insufficient grounding between the trailer and vehicle.

To correct this condition, perform the following procedure:
Inspect and clean the ground wire (white wire) connection on the trailer side of the 7-pin connector.
Make sure that the wires inside the trailer side connector are clean and securely fastened.
If an electrical junction box exists on the trailer, make sure the wires inside the junction box are clean and securely fastened.
Once this procedure is complete, check to see if the condition has been corrected:
Remove the original trailer ground wire (white wire) from the trailer side of the 7-pin trailer connector.
Install a ring terminal (PN 12103512 or equivalent) to this wire and fasten the ring terminal to the metal or aluminum chassis of the trailer using a M6x1x20 self taping phosphate zinc coated screw (PN 11515925 or equivalent).
Pre-drill trailer chassis location with a 3/16" hole. Make sure the trailer chassis location is clean of paint or coating material prior to installation. Galvanic corrosion between dissimilar trailer and screw metals may require that this ground location be periodically cleaned.
Obtain a sufficient length of minimum 10 gauge (5.0 mm2) white wire and fasten with ring (PN 12103512 or equivalent) terminal to the trailer chassis at the same location as the original ground wire.
Install and fasten the other end of the new ground wire into the trailer side of the 7-pin trailer connector.
Install conduit on the original and new trailer ground wires, and secure the conduit to the existing trailer harness.

[CoMoCo]

Glad you got it fixed.

[Precise_One]

Update,
Just picked up the trailer today from Standens, a well known local frame and spring shop. They went through and found a short to the ground wire on the left rear brake magnet. All seems well.
Thanks to everyone who responded! Hopefully this helps someone else down the road.

[TBammer]

I think the truck owners manual set out a procedure for narrowing down the problem to the truck or the trailer.

[Charlie_D_]

OP-Have you found a solution, Please provide update,

[AZ_T_T]

I'm late on this but I did have the same problem on my 2011 Chevy and it was a bad plug on the truck. It was a very easy do it yourself fix.

[Diesel_Camper]

I've had similar problems that it turns out were caused by the brake wires chaffing along the trailer axle parts. I'd get underneath and do a full inspection on the wiring. When it happened to me I was on the one lane portion of Highway 4 in CA headed down a STEEP grade. I was lucky to get stopped and had all 4 wheels on the truck smoking. It didn't help that I was driving too fast to start with counting on the trailer brakes to be there...

[RustyJC]

If your trailer is being serviced at an RV/trailer dealer and you get the "its your truck" story, why not hook up the truck to 2 or 3 trailers there at the lot and see if it's the truck or not?

Rusty

[Precise_One]

Very good point. Honestly I am electrically challenged myself and have to rely on the service people to do their part. Fingers crossed it wasn't just a quick once over and easy answer is " it's your truck"

[Precise_One]

Charlie D. wrote:

Precise One wrote:
Thanks everyone for your responses. I had the trailer in to have it checked out. Received a call today stating they could find no issues. Bearings were to be serviced as part of the visit as well. Will pick up Wednesday and see if there is any change. Have trucked scheduled to be checked Thursday. From there I will try towing a separate trailer and see if issue arises.

Does not mean that the dealer did a comprehensive check. Needs to look at each individual wire form magnet attachment back to truck. Is wiring running through axle tube? What is the amp draw when full voltage is sent to brakes? Takes a DC amp meter. Does he have one?

[dedmiston]

While you're troubleshooting, squirt some WD-40 into both ends of the connection (trailer wiring and truck receptical). I've had this happen a couple of times over the years and the WD-40 cleared it right up. You might as well rule out the connection itself if you can. It's a simple fix if that's actually the problem.