I started my truck and both the ABS and (Brake) warning lights came on. It has done this abot 10 times in the last 3 days. If I turn the truck off and turn it back on, the lights go away. I was told that if the power steering fluid is low, it will cause both lights to come on. Anyone have experience with this? Something to do with the pressure tha pump gives the brake booster? The brakes and ABS still work with the lights on. Any ideas?

 

This may sound stupid...but did you check your P/S level? I don't really see how it would leak to get low like that.

My old '99's ABS module went out and both of those lights came on, you 100% you do not have an ABS problem?

 

I get pedal pressure against my foot when the wheels start to slip. And its interemitant. So, I am positive its not teh ABS pump. Yeah I checked the fluid. It was a little low. But not near the add line.

 

Maybe you have a bad sensor then?

 

The light would stay one though. And throw a code. I have had those go out before. Its not acting like that is the problem. Its just a light. No noticeable malfunction of any parts.

 

Deal with the power steering and brakes is HD trucks have hydroboost brakes, this was done to keep interchange ability
3/4 and 1 ton trucks, gas engines don't need hydroboost brakes, diesel engines don't make vacuum on turbo boost (they are always on boost) so they need hydroboost brakes. Far as ABS light I would suspect wheel speed sensor to ABS acctuator possibly, speed sensor wiring problem.
lets us know what is found.

 

Well, the power steering fluid was just a little low. Not to the add line yet. I filled it back up......and viola. Havent had a problem since.

 

1BadHD, I have the same problem! But, I have stock tire on the right frot and a 275/40-18 (3i shorter) on the left front. My buddy that works at the Dealership told me the sesors were reading the 2 sizes and throwwin a code and to hook it up to autotap and erase it. Going to try this toight. Prob. not the same cause you have but, could be the same solution

 

Does yours light up as soon as you start it without moving the truck yet? If so, its not hte sensors. Why do you have to diff. size tires anyway?

 

no, it comes on goin down the road. But I put my the other wheel(275/40-18) back on, so the fronts are the same and it still came on. The valve stem was leaking. My buddy said it takes like 50-100 ignition cycles before the code resests itself.