[Rusty Scupper]

Getting the dreaded check trailer wiring. Went to mechanic and he said it was the truck. Sometimes voltage for brakes and sometimes not. Had code c1114. He cleared it. Still getting message. He thinks it is the brake contol module by spare.

Went to chev dealer. They said it was the trailer.

Went to trailer dealer and they went thru it, pulled hubs, new plug and still getting message. They think the body control module needs to be reset or something Wring with IBC.

on way home kept getting “check trailer wiring”. Then it flashed up on dic “reduce speed hill decent”. Wtf. That wasnt on.

heading west at 3:00am. Any suggestions? Prev posts say it is most likely trailer. I am thinking chev dealer didnt spend much time on it compared to other two places.

 

[Ron Nielson]

Rusty
It's the trailer. The message to 'check trailer wiring' means that there is a problem with the trailer. Truck is seldom wrong about that. But there have been some who have found that the truck is at fault, but very few that I have heard of.
It's the truck. Any tech should be able to follow the information regarding C1114. See attached. It's a circuit problem.
So it's BOTH! MAYBE!

The attachment specifically applies to my 2008 model and there was a change in the EBCM system sometime after the LMM series, not sure exactly when that happened.
This would be a great time to invest in a subscription to ALLDATADIY.COM so you can keep up with your specific truck. .

 

[Rusty Scupper]

Thanks Ron. That is beyond my capabilities. Now i need to figure out where to take it so nobody points fingers at the other while the $$ keep adding up. I have $500 into it and no resolution.

 

[Rusty Scupper]

Whats odd is the trailer place had a test box. Plugged trailer into it. Had trailer jacked up and every time we hit the brake switch tires stopped spinning. While plugged into truck maybe they stopped 50% of the time. Not sure if that changes anything.

 

[Ron Nielson]

See if there is an auto electric shop in your town. They specialize in problems just like the one you have. They read diagrams, do testing, install parts, re-test after parts installed., most often cheaper than the dealer charges. You have a code which will get the tech started and all you have to do is to stay out of the way (and pay before you leave, of course).

 

[heymccall]

Whats odd is the trailer place had a test box. Plugged trailer into it. Had trailer jacked up and every time we hit the brake switch tires stopped spinning. While plugged into truck maybe they stopped 50% of the time. Not sure if that changes anything.

By design, you can't lock up the trailer brakes while stationary.

Measure resistance between blue wire and white wire on trailer. Report your findings here.

 

[Rusty Scupper]

I will do testing when i get back home. On trip first hour got message repeatedly. Next 8 hours didnt get it. Last hour got it once. I am going with the assumption it is a bad ground. Will check after vacation. It is a time to unwind and have a beer or two

 

[DrHolliday]

I will do testing when i get back home. On trip first hour got message repeatedly. Next 8 hours didnt get it. Last hour got it once. I am going with the assumption it is a bad ground. Will check after vacation. It is a time to unwind and have a beer or two

I had this same issue in my 2015.5 LML.

I was on a 600 mile trip with my 5th wheel and kept getting check trailer wiring message. For me it was happening every time I went up or down any hill. When the message would pop up I had no trailer brakes but the trailer lights kept working. It was a little hairy when I got in the mountains in Vermont and kept losing trailer brakes.

On that trip I had a couple sharp turns so I had to slide my hitch. When doing that my breakaway cable got caught and I didn't notice. When I turned the breakaway switch was activated and locked up the trailer brakes. After the second time I didn't have any issues with the check trailer wiring message. Only thing I can think is a ground was loose and one of the times it got the full 12v from the break away switch it fixed itself...

Since then I've traded that truck on a 2020 and still have the same trailer. I have towed it a few times and haven't had any issues.

Just to add a comment, when the break away is pulled and the trailer is connected to the truck it has issues. I had to let the truck sit for about 5 min shut off, then plug the trailer in and start it to get the trailer connected message to show up. It was a real patience testing experience on back mountain roads in the dark in the middle of nowhere... the wife and kids were not amused.

 

[Rusty Scupper]

Followup - Back from vacation but it has been to hot to work on it. I did borrow a friends 30' Load Warrior Trailer and it didn't ding once. Based upon that I think it is the trailer. I will start with grounds, and any visible damage to wires. If it comes to pulling hubs, that is beyond my expertise. I will post back after I inspect further.

 

[heymccall]

If it has 2 axles, the resistance between blue and white on the trailer should be 1.1 ohm. Higher than 3 is an issue as is lower than 0.8.

This can be tested without taking anything apart.

 

[PA24Pilot]

I fought this problem for a long time. The problem is the brake wiring goes through the axle tube. The wire is loose inside the axle, as you are going down the road the wiring is moving and wearing through the insulation. That is why the problem comes and goes as you are driving. I rewired the wire going through the axle but attached it to the outside of the axle, problem solved for two years now.

 

[Rusty Scupper]

heymccall - Correct, it is a 2 Dexter axle trailer. Using an old analog ohm meter it read 1.0 ohms. I will see if I can get a digital ohm meter and test again.

PA24Pilot - You are probably correct. I assume you have to take the hub off to get to one end of the wire and then you can pull thru the axle tube for inspection/testing? If so, I will see if there is any visable wear as it enters and exits and go from there.

Thanks everyone.

 

[Ron Nielson]

I can't see your trailer from here, but I doubt you will have to pull the hub off to do what you need to do. The connection likely will be outside the brake backing plate, with wiring feeding both axles, both sides. If you decide to resize, you should be using wiring made specifically for this purpose. It is substantially more protected from wear through, cuts, abrasions, etc. E-Trailer will have this.

 

[Rusty Scupper]

Awesome, thanks Ron. I will take a further look. You guys are awesome!

 

[heymccall]

At the age of that truck, I'd be looking hard at the itbc output relay, since you show 1.0 ohm on trailer. It can had for less. Here in Pennsylvania, expect the bolts (m6) to break. Changed quite a few. Typically, a visual inspection will reveal a swollen housing.

 

[Rusty Scupper]

heymccall - Thanks for the insight on the trailer break relay. Being I do not have the problem with a borrowed trailer I am going to pursue the broken/frayed wire somewhere on the trailer. I will keep this in my back pocket should I not find something. I only have 27k on it so fingers crossed the bolts wont break. Hopefully the wife's projects for me are kept to a minimum and I can spend some time checking into this.

 

[PA24Pilot]

You do not have to pull the hubs to replace the wiring. The magnet connections are on the axle side of the hubs. If your wire that goes cross axle is a two wire flat cable, not with another insulation around them to make it round. I can say with 99.9% confidence replacing the wire will fix your problem. The cable lays loose inside the axle and has either "S" or "Z" bends in it. The points of the bends are a high wear point. This wears through the insulation at that point of contact and shorting out to the axle tube., causing the trailer disconnected error.

 

[Rusty Scupper]

PA24Pilot - I think you are on to something. I just need time set aside to dig into this. Hoping for the weekend but temps are going to be in the mid 90's. Maybe a cooler full of beer nearby will help.

 

[Rusty Scupper]

I crawled under the trailer and did a quick inspection. The wiring is all in wire loom. It doesn't run thru the axle but against an aluminum angle structure that runs the width of the trailer. It is secured about every 12". I was surprised how well it was done. There is a ground wire with a ring terminal on both sides of the trailer by the brakes. Everything looks good, so I am going to replace the ring terminals, shine up the aluminum and use a bolt or self tapping screw instead of the current rivet. If that doesn't fix it I will unsecure the wiring, remove the wire loom and do an inspection on the wire. Maybe there is a splice somewhere in the loom that is bad.

Thanks again everyone, I will keep you posted on my trials and tribulations.

 

[heymccall]

The ground path from the brakes needs to go directly to white wire.
Are you certain that the white wire is securely grounded to the frame, especially if the frame is the ground for the brakes?