Service trailer brake?

[pavetim]

Not really a tunning question but anyways I got a service trailer brake error once but since I towed my rv yesterday now I get it everytime I start the truck, Trailer brakes worked good yesterday too

 

[duramaxmt]

check for codes maybe your brake switch under the dash

 

[TheBac]

Moved to towing.

Have you double checked the wiring and connections from the truck all the way back to the brakes? Any chafing or wear thru?

 

[pavetim]

Hooked up my rv today and no brakes. I am going to look for the obvious things but dealer wants $95 to diagnose. You think the integrated controllers are good enough to warrant the money to have it fixed? Or go with a P3 and forget the integrated one? Trying to find prices on a brake max but can't find much on supposedly the best controller out there

 

[Ron Nielson]

If your message on the DIC says 'SERVICE TRAILER BRAKE SYSTEM' the problem is your truck, not your trailer. If you get a message that says "CHECK TRAILER WIRING" , that's the trailer problem. So make sure you look carefully at the error message.

Here's a pretty good discussion about the problem: http://www.justanswer.com/chevy/4jjy3-chevrolet-silverado-2500-hd-wondering-one-gm-tech-s.html

 

[Tone72885]

I had the same thing happen on my truck, only did it on one of my trailers, found there was an exposed wire on the trailer brake wire going into the brakes.

 

[NC-smokinlmm]

Does your cruise control work properly?

 

[pavetim]

Yes cruise works fine. I read it was probablycthe relay under the rear. Guess three are only three components in the system. I ordered a relay it's only $35

 

[pavetim]

I have efilive but not showing any codes I'll take it into autozone and see if they pull any code or maybe see if i can talk dealer into seeing if there are codes for me al tho probably charge me no matter what anyways

 

[pavetim]

Well changed relay and didn't fix so guess I'll start looking for wires

 

[pavetim]

Ok strange happenings. I hooked it up to truck then turned key on. Now it says trailer connected and the bars increase with gain but when i turn truck off and disconnect and turn truck back on it says service trailer brake system. Why is it giving an error if it seems to work fine?

 

[pavetim]

Ok not aure if connected but other issued just popped up. My cruise works fime but the green light on Speedo doesn't come on when set and my compass isnt working it just shows 2 dashes

 

[pavetim]

Oh and now steering wheel heater doesnt work, light for how haul mode doesnt come on. 381 views amd no other ideas?

 

[Ron Nielson]

If you have camper wiring option, check those wires and make sure they can't make electrical contact with anything. I wrapped mine in plastic, then wrapped with tape.

 

[Hoffie]

Have you found anything yet to cause the issues? Sounds like a loose wiring harness with all of those different issues being intermittent like that.

 

[Ron Nielson]

I hooked it up to truck then turned key on. Now it says trailer connected and the bars increase with gain but when i turn truck off and disconnect and turn truck back on it says service trailer brake system. Why is it giving an error if it seems to work fine?

The ITBC system looks for the proper resistance on the brake circuit (thru your 7-way plug) and since your trailer is connected, ITBC thinks everything is fine. However, you unplug the 7-way and now the ITBC still looks for correct resistance and it's not there, BUT something, somewhere else, is providing feedback. That something is usually the blunt cut camper wires or bad 7-way connector at the rear bumper. Of course, there could be other things but that's the likely problem areas. Common and very frustrating problem to troubleshoot.

The fact that you do get TRAILER CONNECTED when your trailer attached means that the system works with a trailer (you have trailer brakes), but the ITBC system finds some fault when no trailer is connected, often associated with wet weather, shorted or frayed wires, dirty connections, etc.

 

[Passin Thru]

Try the grounding between the ball and the trailer. Mine , if I get too much grease, won't ground to the truck and it goes haywire. Sometimes my marker lights blink on and off. We have 5 trailers so it's a constant headache, boat, trash, livestock, flat and TT. Right now it blows fuses to the battery on the trailer.

 

[trashygasman]

With that many random things not working it sounds more like it might be a fuse. Even if it isn't blown it might not be making good contact in the panel.

 

[jlawles2]

Try the grounding between the ball and the trailer. Mine , if I get too much grease, won't ground to the truck and it goes haywire. Sometimes my marker lights blink on and off. We have 5 trailers so it's a constant headache, boat, trash, livestock, flat and TT. Right now it blows fuses to the battery on the trailer.

If you are relying on the ball to ground the trailer, then you should not be pulling a trailer. Relying on the ball to do the job of the trailer connector can lead to multiple issues with both the trailer and the truck. It can also cause accidents because the people behind you may not know that you are stopping since the ground to the trailer will always fail at the worst time.

To the OP, Check the fuses, and even check the connector on the back of the 7-way at the rear of the truck. If no luck start following the wire loom along the frame rail to the front, you may find that the loom is pinched between the frame and one of the body components, or the fuel tank. Don't be afraid to open any connectors you find along the way to verify that one or more of the pins is backing out of the plug.

 

[bmc1025]

If you have the camper harness it will be tucked up along the frame rail by the fuel tank. the connector looks just like the one that connects into the back of the 7 way connector. It may be wrapped in tape.