ABS light help.. Please!!

Discussion in 'B5 platform' started by t99rick2002, Aug 17, 2012.

  1. t99rick2002 New Member

    I own a 98 a4 1.8t quattro. Lately I've been sinking some money into her to fix some overdue repairs. One of them being the ABS module. The abs light, and brake light have been on for roughly a year now (abs light is solid, brake light blinking.. and also the three really annoying beeps everytime you turn the car on). My first step into solving this problem was to run Vag-com and see if I could communicate with the abs module. No communication at all. I couldn't even access any other modules without removing the ABS module fuse. After coming to the conclusion that the ABS module is most likely faulty, I matched the part number and ordered a remanufactured module from autoecu.com.

    Just a couple hours ago I installed the remanufactured abs module and ran Vag-scan. I was able to communicate with the controller immediately. Scanned for faulty codes... Nothing. No codes at all. But.. My abs light, and brake light were still there. Pretty disappointing. I tried disconnecting the battery for 30 minutes hoping to reset the ecu and clear the lights, didn't work. I also tested the wheel speed sensors because I've heard those can cause the abs, and brake lights. The wheel sensors were all dead on according to vag-scan, all registered the same speed while driving down the road.

    So, I'm stumped. If anyone has any advice, or can think of anything I'm missing it would be greatly appreciated.
  2. Advertisement

  3. t99rick2002 New Member

    Update: I recently picked up a fault code under the 'auto trans' module stating: 00526 brake light switch f, implausible signal.
    When I try to clear the fault code it immediately comes right back. I'm going to try to replace the brake light switch because it is a very cheap part and I am out of ideas. It's strange though because I still have brake lights. I thought if the brake light switch was bad I wouldn't be getting brake lights.
    • Premium Supporter

    PetrolDave Super Moderator

    This is a common problem, widely reported on Audi websites.

    The brake switch is actually a double switch, one to work the brake lights and one to communicate with the ABS module. It's the second part of the brake switch that is faulty, which then confuses the ABS module - hence the warning lights.

    You need to replace the brake light switch.
  4. t99rick2002 New Member

    Update: Just installed a new brake light switch this morning. No luck. Still have the abs light, and brake light on the dash. Brake lights work fine. I was able to clear the brake light switch fault code and it didn't come back immediately like it was. As it stands I am not picking up any fault codes under any of the modules. And like I said before, my wheel speed sensors seem to be working fine. My front rotors are in really rough shape. I've been meaning to replace them... Does anyone think that that could cause the abs light, and brake light? I'm just out of ideas. Thanks in advance for any advice.
  5. 15zerodos New Member

    I got the same problem, try to scan but no luck....
  6. Jermsica Member

Share Audi Forum with friends