Hi All,
I have a similar issue but maybe not as simple. I have a Q7 which i bought from Audi 2nd hand and 2 weeks after my 12 month warranty ran out I had a warning sign come up saying 'Brake Servo Restricted - continue to drive but visit garage' or words to that effect. Unfortunately due to personal reasons I failed to purchase extended warranty and also didn't manage to get the car into the garage for a few weeks. The warning sign then changed to 'Brake: Fault - Stop Immediately' - or words to that effect and comes up every time the ignition is turned on. A few days later the brakes started to crunch every time they were applied and I eventually managed to hand it into my local garage who changed the brake servo sensor which cleared up the crunching but the warning sign still remains. They said they couldn't clear the fault and it seems like the ABS unit has 'clocked itself out' and will need replacing. I took it to Audi to look into and they diagnosed it as a possible faulty brake pressure sensor which they suggested to replace at a cost of £185 and if that doesn't work then it'll need a new ABS unit and hydraulic part to fix the issue at a cost of around £3000. When i told them the sensor has been replaced recently the only option they gave was therefore to replace the ABS unit.
The sensor that my garage replaced is branded Sensata with OEM number 5QA 906 207A, which i'm assuming is ok to use?! I cant see how Audi changing the sensor will correct the issue as I've had 2 independent mechanics (one of whom used to work for Audi) say that the ABS control unit needs replacing but may be able to get fixed for a few hundred quid? has anyone heard of this? I really don't want to spend £3k if I don't have to.
Your help and advice in this is very much appreciated.
Look forward to hearing from you
Dev