service trailer break system Service Trailer Break System

Tyler Sywyk · February 17, 2018

Hello, I own an 08 GMC Sierra 2500HD Diesel Crew Cab Long box pick up, it's throwing a display message, but not giving me any codes, the message is service trailer brake system, it used to show that message and then I had it brought into the shop the second of July and they replaced the trailer break relay in the rear, had to change out some eye connectors at the fuse box. They also replaced the fuse. Worked great again from then to about a three weeks ago and this was including an 11 000km trip towing the trailer, it brought the message up again. The truck had been sitting and driven every once and a while, a bit of idling this winter as well, but no towing. so I replaced the fuse because it looked blown. After replaced it work fine again no more message thought maybe wet weather caused it. Now unfortunately now again yesterday I went to use it again and the message comes up, it was just recently used a few days ago and no message, today we have some dense fog as well as some rain. I think it only happens when it rains heavy or fog.. I am not entirely sure on that though. I replaced the fuse in the fuse box for the (ITBC) The one I changed out before to get it to work, and this time it did not work and nothing changed on the dash message still up. I can more than easily replace the Relay without any issues, but I don't want to do that if it is just going to create the exact same issue. Any ideas on what might be causing this?

Also on a side note, whenever I start the truck it puts out grey smoke until it has warmed up passed about 79-85 degrees Celcius (174F-187F), which is normally after driving for about 5 mins 10 at most or letting it high idle until that temp, it also does smoke when driving until warmed up. it never puts out black or blue smoke. Its grey, just as it is on a cold day in a gas engine. today we've reached the highest temp lately about 8 degrees Celcius and it still smoked. It never did this in the summer or fall just after it got cold. So I am just wondering if this is normal or if something is causing this to happen when it shouldn't be. Could it be something as simple as it needing an oil change? Or also does it need a long drive at highway speed to deal with burn cleaning the DPF? I am a new owner to this pickup, and it is my first year with it so I am new to diesel's and don't know what to expect from them.

Any help Is much appreciated!

grizzlyltz · February 17, 2018

On the exhaust smoke , I would say normal, most likely water vapour / steam

Grizzly

Tyler Sywyk · February 17, 2018

50 minutes ago, grizzlyltz said:

On the exhaust smoke , I would say normal, most likely water vapour / steam

Grizzly

Glad to hear that. Thanks for the fast answer!

swathdiver · February 17, 2018

You need a scan tool like the Tech2 to read those internal codes. Could be a brake switch.

Tyler Sywyk · February 17, 2018

6 minutes ago, swathdiver said:

You need a scan tool like the Tech2 to read those internal codes. Could be a brake switch.

Though you could be right, this switch was replaced about a year ago. So I find it unlikely for it to be that, but it is more than a possibility, and I will consider it, as well after I get some other opinions on what it could be. I have a feeling it has to do with some wiring or something in that matter that is getting wet and is shorting out the system but has now burnt through the wire or something like this. just speculation. I will definitely keep what you said in mind! I will also try and locate a Tech2.

Thanks,

Tyler;

grizzlyltz · February 17, 2018

Have you hooked up to a different trailer to eliminate yours?

Grizzly

Tyler Sywyk · February 18, 2018

On 2/16/2018 at 11:09 PM, grizzlyltz said:

Have you hooked up to a different trailer to eliminate yours?

Grizzly

Yes, its had different trailers hooked to it, though it hasn't had a trailer hooked to it for almost 7 months and the message only popped up about 3 weeks ago for the first time.

Tyler Sywyk · February 23, 2018

On 2/16/2018 at 7:58 PM, grizzlyltz said:

On the exhaust smoke , I would say normal, most likely water vapour / steam

Grizzly

On the exhaust side here is an image showing it. Just wanted u to know what it looked like. it was less than 5 mins.

grizzlyltz · February 23, 2018

On the exhaust side here is an image showing it. Just wanted u to know what it looked like. it was less than 5 mins.

Looks normal
Does the smoke linger around or does it disappear?

Grizzly

Tyler Sywyk · February 23, 2018

16 minutes ago, grizzlyltz said:

Looks normal
Does the smoke linger around or does it disappear?

Grizzly

disappears

Tyler Sywyk · February 25, 2018

Okay so, today I managed to have a look at the trailer relay. It looks melted, after seeing this i remember the shop that "fixed" it before said it was melted so they replaced it. I also believe that i found why replacing the 15amp fuse named (ITBC) wouldn't solve the issue, because the 30 amp fuse named STUD-2 which means Fuse Blunt Cut Wire, Integrated Trailer Brake Controller Solid State Relay (JL1) was blown as well. I have not replaced the 30amp fuse yet because i am not sure if its just going to fry it again or whats gonna happen, also i haven't been into town yet to get a fuse. So any ideas on what could be causing these fuses to blow and what is causing the spot where the 15 amp fuse to look melted and as well as the relay to be melted?