ABS light is on and breaks seem to be locked - 2001 Audi A6

You may have exceeded your "throw", braking shoe/ pad distance, and locked up one wheel or more. Calipers and shoe pistons have tolerances on distance they can go, and if a disk or drum has exceeded its usefulness and worn past the tolerances allowed, a cylinder or caliper may lock up after pushing out to far.

Is the break pedal stiff? with the ABS light on and the break light on sounds like your breaks might be locked or locking up which could be why the transmission isn't shifting

Your abs and traction control lights should only come on when you start to slide while breaking(ABS), and when your wheels spin in place when excelerating(TC). If those 2 things don't happen, which with some people they never do, you should never see the lights come on. Only when those mechanisms are in use do the lights come on. And they will always flicker as that is what abs and tc are, intermitant surges to break up the constant. ABS does this for obvious reasons...anti lock break, so when you slide, the abs "taps" the breaks in short bursts so they don't lock up. TC "taps" the exclelrator when it slips. Those "taps" are what trigger the lights on your dash, which is why they flicker and don't stay on.

It's most likely a wheel speed sensor at fault. Check the connectors and wires behind each wheel. Sometimes corrosion builds up in the connectors or sometimes wires break...and sometimes the sensors just plain fail. Your brakes will work just fine but you've prolly lost ABS function. If you can lock up your brakes, ABS is disabled until the signal is restored.

If the the abs module fails you still have breaks BUT if you need to apply the breaks to the floor the abs will not work which could allow you to go into a slide because of loss of traction. the abs system pumps the breaks to prevent your tires from locking up

Well you can drive without ABS the brake light came on because the ABS. I would have it serviced they might tell you the ABS unit is bad you don't need ABS they just prevent your tires from locking up during heavy break use

check for codes with scanner it most likely is the abs sensor on the rear differential housing that is bad easy fix

I also have a 96' shasta RV 26' E350 Ford chassis... ABS light comes on whenever it feels like it. We have 20,000 miles on the RV. We love the Motorhome but am constantly worried about the light. Our mechanic said not to worry about it.. Not worth the expense to fix it. anyone have a clue? grandmanomi

did you accidently unplug a rear speed sensor

If your brake lights don't work Its because you blew the fuse  which Is located In the main fuse panel under steering wheel.  Without break lights your rover will fire up nice but wont shift out of park until you replace the fuse.  If your ABS Is acting up It Is also an easy fix.  Disconnect the ABS from each wheel.  You still got all wheel disc breaks that work great but no ABS.  Your other option is  thousands of $$.  If your breaks are weak check your master cylinder and make sure you got enough fluid and that you are not loosing the fluid.  If you notice you are leaking brake fluid because you have to keep filling it up but cannot find a leak anywhere.  I bet I know where It is.  Check your rear break lines and make sure one of them didn't get caught in your rear springs and pinched ever so slightly when you were doing dounuts In the snow.
Good luck,