I just recently removed mine and installed a Tekonsha prodigy P2 after having problems like yours over 145k miles.Its real easy,Etrailer.com has a write up on it. Aftermarket Brake Control Wiring for 07-13 GM Full-Size Truck with Factory-Integrated Brake Control | etrailer.com

 

Its the trailer plug. Happens to me all the time. Try taking a wire brush to it clean up the contacts a bit

 

Jeff

What are you thinking?? You have a NEW TRUCK UNDER FULL WARRANTY!!! Take it back to the dealer and tell them to fix it. Take your trailer with you so they don't have an excuse for not being able to find the mistake when it's hooked up to YOUR TRAILER.

Sure you could do it yourself, but why do that? Get the ITBC working correctly now and you'll be glad you did.

 

Jeff What are you thinking?? You have a NEW TRUCK UNDER FULL WARRANTY!!! Take it back to the dealer and tell them to fix it. Take your trailer with you so they don't have an excuse for not being able to find the mistake when it's hooked up to YOUR TRAILER. Sure you could do it yourself, but why do that? Get the ITBC working correctly now and you'll be glad you did.

My guess: The truck dealer would say it’s the trailer and the trailer dealer would say it’s the truck.

 

They'll tell him to fix his trailer plug or have sweet could not replicate on the ticket. It'd be a waste of time

 

I cleaned up my plugs on both sides,and chased the wires for breaks and never found anything wrong.There are so many threads on this issue that it makes me believe the ITBC is faulty.Yes,some of you never have a problem with it,but then again you probably don't haul a trailer 400 miles a day,seven days a week.

 

126,364 purchased 11/18/14. I get it from time to time but its the trailer plug or it would do it more consistently on all the trailers

 

You must be hauling campers with that many miles.

 

Yup as well as utility equipment. Ive only gotten the message on maybe 4-5 out probably 30 or more trailers ive pulled. I always chocked it up to wonderful electricians at forest river. Ive had 4 itbc fuses blow and now carry a bunch with me since the micro j-case can only be bought at a dealer

 

Dont know if this will correct your issue, but it sure as damn corrected mine.

Ive been dealing with increasing issues with the check trailer wiring warning. Started out once in a blue moon and recent it damn near went continuous and drove me crazy. Thank god i work in the hospital or the dinging would have drove me nuts. I went through everything at the connector side, re-ran some wires, fixed the main trailer ground from the battery (it was through a thin piece of metal instead of the frame), removed the break away switch from the mix to make sure it wasnt causing issues and absolutely nothing fixed the issue. I decided to move to the axles themselves. Keep in mind my truck is brand new and the trailer is damn near brand new as well. First two axles on the passenger side on my toy hauler were covered in grease, over filled at the factory. Spent time cleaning them. The rear passenger side is where it got interesting. As soon as I pulled the drum off, the magnet falls to the ground. The clip that holds it on is missing/mia or never installed. The wiring wasnt snapped on by the clips to the arm either. It appeared that the wiring made it way to the brake drum and melted/twisted it around creating a short in the system. As soon as I pulled the wires apart, the truck said "trailer connected" I cut the wires, removed them from the housing and took the magnet out. I plan on going down to the trailer shop in the morning and buying a new magnet, but the 15 miles i put on the trailer since cutting the wire, I've had 0 issues. Attached is a picture of the magnet and wiring

While the trailer is still under factory warranty, and I know I could have had it covered, it cost me only time and the price of a new magnet. Plus I have the satisfaction of knowing I fixed, and it's April and almost every trailer ship is a minimum 1 month out if I'm paying for it and longer if the factory is paying for it.

 

Dont know if this will correct your issue, but it sure as damn corrected mine.

Ive been dealing with increasing issues with the check trailer wiring warning. Started out once in a blue moon and recent it damn near went continuous and drove me crazy. Thank god i work in the hospital or the dinging would have drove me nuts. I went through everything at the connector side, re-ran some wires, fixed the main trailer ground from the battery (it was through a thin piece of metal instead of the frame), removed the break away switch from the mix to make sure it wasnt causing issues and absolutely nothing fixed the issue. I decided to move to the axles themselves. Keep in mind my truck is brand new and the trailer is damn near brand new as well. First two axles on the passenger side on my toy hauler were covered in grease, over filled at the factory. Spent time cleaning them. The rear passenger side is where it got interesting. As soon as I pulled the drum off, the magnet falls to the ground. The clip that holds it on is missing/mia or never installed. The wiring wasnt snapped on by the clips to the arm either. It appeared that the wiring made it way to the brake drum and melted/twisted it around creating a short in the system. As soon as I pulled the wires apart, the truck said "trailer connected" I cut the wires, removed them from the housing and took the magnet out. I plan on going down to the trailer shop in the morning and buying a new magnet, but the 15 miles i put on the trailer since cutting the wire, I've had 0 issues. Attached is a picture of the magnet and wiring

While the trailer is still under factory warranty, and I know I could have had it covered, it cost me only time and the price of a new magnet. Plus I have the satisfaction of knowing I fixed, and it's April and almost every trailer ship is a minimum 1 month out if I'm paying for it and longer if the factory is paying for it.

I read your post. Took my 7 pin trailer side connector apart removed the one wire for the brakes. Drove it 35 miles home. No more dingy thing. I will dig into the brakes this week sometime.
If any one else is having this issue look towards the trailer brakes and or it’s wiring.
that is obviously where my pro was/is as well.

 

My 2015 road warrior toy hauler does this non stop. I have tried using the plug in the bed and the plug on the bumper. I've pumped dielectric grease into all the plugs, it's random. Once it starts, it does it non-stop while you drive. Constant dinging for 30-40 minutes while you drive makes me want to blow a gasket. Never had a trailer give me the problem except my toyhauler.


Sent from my iPhone using Tapatalk

 

GM Check Trailer Wiring error msg and TSB

Thank you all for your ideas! Most of the "fixes" described in the forum will work, at least for a while, but the problem will not have been addressed.It certainly hasn't been addressed by GM in either of their TSBs PIT5311A & B (for the different years affected). In fact, GM has the audacity to blame the trailer-side wiring and/or the "...trailer-side connectors that do not meet the SAE specification".!!
Why hasn't anyone noticed (or mentioned) that the only trucks having this problem have the 7-way/4-way combo plug oriented with the 7-way on top? GM certainly won't mention it (see below), and you know the folks in the trenches in the Service Departments have probably been told not to say anything to the customer. You know the TSB did not arise out of thin air, but because of a large number of errors arising...with customers who have the combo plug with the 7-way on top. Read on, if you're interested:
The real problem, and the reason folks have not had the error with older trucks or Fords, etc. is because GM came up with a great idea that was poorly implemented. They figured combining a 7-way and 4-way plug would save using converter plugs (correct) and save customers having to carry converters for boats and other 4-way wired trailers. Probably a nice gesture overall.
However, they did not bother to spec that the 7-way has to be on the bottom of the 7/4 combination plug. If you walk a dealer's lot, you'll see some of the trucks have 7-way on top, others have it on bottom. The truck-side 7/4 combo plug snaps in very nicely to the bumper with its cute little spring clips (another good idea), but the plug can NOT be inverted to put the 7-way on the bottom, where it should be, and like it has been for years. The two bottom terminals in a 7-way, when it is normally oriented with the truck-side lid lifting UP. are the GROUND and TRAILER BRAKE.
Hence the problem with GM trucks that have the 7-way on top: as the trailer side plug and wire hang and wiggle (imagine that, what a surprise for the GM engineers!), one or both of the two terminal connections (GROUND &/or BRAKE) can lose contact intermittently, causing the "DING, DING, DING: CHECK TRAILER WIRING" followed shortly by "TRAILER CONNECTED" as the terminals reconnect. This is also why your "Trailer Gain" display on trucks that have that in the info cluster will "grey out" and not show any activity when the connection is loose, then light back up to the normal orange and show activity when the connection is tight.
The bumper stampings are apparently done in batches, or perhaps at different locations, resulting in some bumpers having the 7-way hole on top and others with the 7-way on the bottom. Since the plug can not be inverted and GM did not think to spec the bumper stampings correctly, they chose to place the source of the problem with the trailer-side wiring!! Drill and add your own ground wire indeed! Sloppy and lazy on GM's part. Or buy a new trailer-side connector (at your expense), because yours probably "...does not meet the SAE specification". Really??
The REAL fix would be for GM to swap out your current bumper stamping with one having the 7/4 combo plug oriented with the 7-way on the bottom. I can't imagine GM would ever voluntarily do this, unless there were enough safety-related problems &/or accidents involving lack of trailer braking. Why wouldn't GM at least provide the Pollak trailer-side connector to the customer and recommend they visit their favorite RV service center? Or perhaps reimburse the customer for the cost of the Pollak trailer-side connector?
All of the affected vehicles are $ 50,000 plus, so a gesture of customer goodwill on the part of GM to really fix this problem (instead of placing blame on the trailer side) would certainly be reasonable. Wait! What was I thinking?! If they can get customers to foot the bill by not being transparent about their engineering snafu (for at least five model years!), nobody in GM has to be accountable.
I'm going to buy the Pollak trailer-side plug and start surfing the local and regional salvage yards for a "correctly" stamped bumper.
Good luck to you all!
Gordon Flowers
Sacramento, CA

 

I have been towing a 9,000lb travel trailer with my 2015 3500 DRW. The last 3 trips out we have been getting a random "Check trailer wiring" "service Trailer Brake System" "Trailer Connected" messages on the DIC. I have towed this trailer with my old truck and just started towing with this truck in March. We made 5 trips out to and from with no problem.
The first trip it happened on we were 2hours into the ride coming home. It popped on a few times saying "check trailer wiring" then would say "trailer connected". When the message occurred I could tell that my trailer running lights remained on still so I didn't figure the plug came out or the wire got damaged. We pulled over in a gas station and checked the plug and connections and all seemed good. We kept going on our way and the message didn't come on anymore.
The 2nd trip it happened on we didn't see the message in our 1 1/2 hr ride to our destination. On the way home about 1 hour into the trip, the warnings started again and kept coming off and on. Stopped and checked the plug and connection and all seemed good.
The 3rd trip out, 1 hour into the trip out it started again. Coincidentally I came over a bridge and we bounced quite a bit then it started coming on. Kept coming on and off until our destination. I noticed that when it said to "check trailer wiring" the trailer brakes wouldn't work coming down a big hill. I had tried to manually apply the trailer brakes through the factory brake controller on the dash and got nothing.
When we hooked up the trailer to leave and head home we immediately got the "Check Trailer Wiring" and "Service Trailer Brake System" messages as soon as we plugged in and hadn't moved. A buddy and I started looking over things. I checked the ground wire for the trailer connection and put a new clean end on it and reattached it firmly. No change.
We checked the Trailer brake fuse under the hood and nothing appeared blown. swapped it with another like fuse and still no change.
pulled out a test light and checked the function of all pins on the trucks 7 pin connection. When we tested the trailer brake controller pushing signal to the 7 pin connection it was completely grayed out on the dashboard and didn't send a signal to the 7 pin connection. I disconnected the back of the truck 7 pin connection behind the bumper. We tested that side with a test light and still nothing from the trailer brake termianl. We had to get on the road so we started on our drive. We still had brake lights on the trailer but there was no trailer brakes. We started driving down the road with the DING DING DING going off over 30 seconds.. IT SUCKED! about 40 minutes into the drive it stopped. The trailer brake output started showing when I hit the brakes, the manual brake controller was working properly. The rest of our 1 hr drive was uneventful. Plenty of bumps in the road and no more messages or DING noises. I tested the Trailer brake pin on the truck side again now that things were working. Still didn't show any voltage coming through and the DIC trailer brake display was grayed out. SO I am not sure that test proves anything. Maybe the trailer brake doesn't output anything unless another part of the 7 pin trailer side is connected too?
the terminals on both trailer and truck side 7 pin connection look pretty good. Very minor corrosion. I took some electronic terminal cleaner to them and scraped them up a bit. I applied some dielectric grease to both sides.

So looking for some guidance from the original post Jeff11, what did you determine to be the cause and solution?
Thanks in advance.

 

You might check the wiring going to brakes on trailer, sounds like an intermittent open. There is also a relay or some other electrical components in the box under bed. Trace the wires back from plug on truck to that box and reset connectors.

 

I have had the same issues on my 2017. After checking the wiring and finding no problems I changed out the wiring harness and plug on the trailer. Didn't fix anything, same message. To make a long story shorter I found when I plug the trailer plug in that if I use a small hammer to lightly tap the plug so that it has a good connection that I no longer get the message. In July I pulled the trailer to West Texas on a 9 hour trip and as we were pulling into the park the message came on. I don't know if if this was helpful or not, but it is easy to check.

 

So thanks for the replies guy. I hit the original poster up on PM. He linked his problem to the true alter. I went and looked at my trailer today. I popped one tire off and got under the drum and found a broken wire running to my magnet for the emergency brake.
I have the part on order to replace but I’m pretty sure that’s going to be the problem.
I recently hit a curb pretty good in a tight gas steroid parking lot. Must have knocked the wire loose and got it stuck inside the bearing as it rotated. I’m guess it was intermittent If the wires some how made a connection and made it turn off.

 

So thanks for the replies guy. I hit the original poster up on PM. He linked his problem to the true alter. I went and looked at my trailer today. I popped one tire off and got under the drum and found a broken wire running to my magnet for the emergency brake.
I have the part on order to replace but I’m pretty sure that’s going to be the problem.
I recently hit a curb pretty good in a tight gas steroid parking lot. Must have knocked the wire loose and got it stuck inside the bearing as it rotated. I’m guess it was intermittent If the wires some how made a connection and made it turn off.

Did this fix your problem? Sounds like all other suggestions are hit-or-miss. Having the same issue with 2016 RAM 1500. Thanks in advance.

 

I bought a new oem break controller because the old one sucked going off all the time.Just drove 2500 miles with the new one.
At 700 and then at 1100 miles I got a quick check trailer,connected.Maybe 2 more times in the 2500 miles.
Way better controller than original dash puncher! That one drove me nuts. I’m talking totally missing a song on the radio!
Wish I knew of the bad part long ago.Not that it did it all the time but when it did it sucked,the old one that is.
If this one goes hay wire 1 time I’ll install a prodigy.

 

I've got a 2018 and Haul a slide in Truck camper. Mine does this constantly plugged into the bed connector if my light selector is in the Auto mode. It stops when I move in one click to the right. it's done it since new.

 

2016 Yukon XL

I got the same message for a few hundred miles a year ago while pulling a 30 ft RV and then it disappeared. Now it started again with no trailer connected!

 

2016 Yukon XL

I got the same message for a few hundred miles a year ago while pulling a 30 ft RV and then it disappeared. Now it started again with no trailer connected!

Divert the air to the floor and the problem goes away.The control is getting too hot or cold

 

My 2018 3500 had the same warning. Turned out to be a loose harness going into the fender well for the in bed connector. I secured the factory harness connector which had come loose, then added a zip tie. Evidently it got rattled enough that it kept triggering the warning. On my trip from Georgia to California the warning would come up several times a day. On my trip back after my repair, it didn’t come on once. In fact it hasn’t happened at all since, and it’s been a year and several thousand miles towing. Might be a long shot but I’d check the wire loom coming from the in bed connector and see if the harness is secure.

 

I put aftermarket controller in and worked better. I wish there was a work around to totally redo the wiring from cab to back, at least new harnesses etc. my trucks a bit older and well been salting her for years!

 

Just had this happen to me on a recent trip from SF Bay Area to Los Angeles area. It was on 12/26 and the trip took 12-1/2 hours, but half way through the trip, I received the Check Trailer Wiring message as well as TSC light coming on. However, I WASN'T pulling any of my trailers.

The TSC light remained on in the dash so I pulled off the freeway I wasn't really moving on and tried to clear it by turning off the ignition and restarting, yet each time, the message and light re-appeared. As I was also travelling with my Wife and dog, my dog started getting restless so I pulled off into a large gravel area left the truck running and let the dog run around and go pee.

When I returned to the truck...warning light was off and message never came back on during the entire rest of the trip. However, I received an email from OnStar explaining that the warning was triggered and to make an appt with my dealer.

Thoughts/comments, should I go to the dealer?

 

TSC light? What does this mean, in English? Maybe Traction Control System (TCS) ??

 

My apologies. Yes, TCS.

 

Don't go the dealer, yet. Scan your truck for DTC codes. If you don't have a code reader, local parts store will read for you for free. Then react to the DTC that was found.



Lots of posts about TCS system problems on forums like this one and also Youtube. Could be any one of hundreds of problems.

 

We’re experiencing the same issue. We just purchased a 2015 GMC 2500HD along with a 2007 feather lite trailer. New brakes were installed along with a junction box and a new cable. Our mechanic was trying to save us a little money using a cheaper plug that was somewhat loose in the truck receptacle so we were having connection issues. After installing a better plug we now have brakes, turn signals, brake lights, emergency flashers and running lights We also have “check trailer wiring” notification along with the annoying sounds.
After searching forums this weekend we’re thinking it would be best for us to have an aftermarket controller installed. We looking at the Tekonsha P3. Especially considering all the problems with the factory integrated system.
My question is, will this solve the problem that is happening because the receptacle has the brake and ground at the top, or will that still be a possible problem? Thanks for any responses. John

 

We also have “check trailer wiring” notification along with the annoying sounds.

I follow problems about the ITBC system pretty closely and have found that when your truck tells you to “check trailer wiring”, that is exactly where the problem is about 90% of the time. And the problem is usually with the trailer wire grounding, or more properly, not grounding, or even shorting. I'd spend a little time checking the trailer's wiring, particularly the electrical brakes, and you'll likely discover the problem.


I used to have a little 21 ft 5th wheel I pulled behind my GMC Sonoma, and lost my brakes in Washington. Stopped in a trailer shop they worked for 4 hours, found the problem, and I'm on my way again. Before I got home, I was in SW Colorado and same problem, and same solution, found problems with the trailer brake wiring. Fixed and I drove home to Kansas. Again I had a problem, same problem, and decided to replace all the trailer brake wiring with 10 ga wiring, and new magnets, and never had a problem again. And you can replace most magnets with stronger magnets that original equipment. One well know problem area is the wire that runs through the center of the axle tube shorting out and the repair is to run the replacement wiring outside the axle with split loom or some kind of additional wiring protection. And make sure your trailer is grounding thru the trailer to truck plug, not thru the hitch.

 

Thank you.
I tested the trailer plug ground pin to the metal on the hitch getting good continuity. As I mentioned earlier all systems are working, but we’re still getting the display and dinging. We’re thinking about installing a Tekonsha P3 bypassing the factory controller. Tekonsha says I’ll need to use a blue wire from the P3 back to the 7 pin.

 

Correct, run a new power lead from controller to rear harness, or find the power lead under the hood and tap it there...