I just installed the quadzilla tuner on the truck (http://www.dieselplace.com/forum/showthread.php?t=330402#) and now I am getting a ABS light and red brake light saying service trailer brake system. What could be causing this? The programmer? Any help is greatly appreciated.

What size tires do you have?

they are 37s

after doing some searching on here looks like you have to play with the programmer with tire heights until the lights dont come on anymore. Guess I will try that and see if it works.

i had the same issues with 35's....i had to get the speedo dead nuts before the light would go off, good luck.....

With 37s you may have problems......35s are as far as you can go without the .......

I have put the tire size on the programmer back to 35's and no code yet. Knock on wood.

Mine is on lately, I had my H2 rims on and BFG KM2, and it was fine and then went back to stock tires and torsion bars were tightened up to get the H2's in. But now I keep getting service trailer brakes message. Any idea, I had the edge juice with attitude on it and took it off for awhile to see if that cleared it but it was still on. I have to schedule a 20k service soon.

Sounds like a different problem than mine. Mine had to do with the tuner itself. I saw some post about the wires shorting out for the trailer system. Maybe thats it.

I've heard of several people having this issue. From what I understand anything larger then a 35" tire is going to cause the ABS light to come on. I don't think there is a way around it currently. Did you call Quadzilla about ti?

I havent called quadzilla about it as I have put the tuner on 35" tire and it seems to be throwing no codes. So I am guessing that is the largest tire to program before ABS lights come on.

If i programed my truck with anything larger than 36.25" my abs light would come on.