While towing my 31' 5th wheel in level 2 and then in level 1, the audio warning sounded and my brake light and ABS light both went on. I didn't really notice any loss of power and when I turned the truck off, the ABS and brake lights went off. This occurred twice on my round trip and seemed to happen when I floored it from a standstill. Any info as to why this is happening?

mine did the same thing when i re geared,but it was on all the time, untill i changed the ratio with the programmer, and i measured my tire with a tape measure to get the exact height,(36.25) not 37 like they say, and that fixed my problem. Now it does come on every once and awile under a good load full throttle, like up tha local pass or something like that, but never full throttle from a stop. Did you change the gear ratio in the front as well?

It came on when i was pulling my 9000 lb trailer up the pass, now that i think of it.The worse thing about it is whenthis happens, you lose your trailer brakes!!!!!! They are tied into tha abs sensor for some reason. I had to pull over and turn the key off and then back on to reset the sensor.It has something to do with changeing the gear ratio, because the abs module is programed for 3.73, after a certain % of difference from stock, gear ratio, tire size, and even heared if one tire is low this could happen.I was told at the dealer that the older trucks could be reprogrammed to fix the tire size and gaer change , but gm took that out of the tech 2 software.

Yeah mine was re-geared with 4:10, mine is only two wheel drive, and everything was reset. Beats the heck out of me what causes it to happen when it is under a load and you're flooring it. I'll give Dan a call at PPE and see what he says

Just talked to Dan and he immediately had the answer. He said to reset my tire size to 34" & 3/4 and not 35". Hope this will help you out also DMWellJr.

How did it work?

I tried changing the tire size and ratio and it never worked and then it went into reduced power