Apologies if this is an old topic only I am new to the forums and desperate for expertise.

I have an Audi A6 1.9TDI 2003 and recently received it from the local garage after they changed a windscreen wash botle motor. On receipt the ABS and Warning Light are permanantly on. I returned it to the garage who admitted that it was not on when they received the car but could not find out why it had come on and can only guess that they plugged it in as they are an Audi specialist garage.

How has this occurred? Could it be something simple that I can check i.e they have messed with something to do with the module moving the washer bottle, changing a fuse or disconnecting one of the sensors or is this shere coincidence.

I am stuck for ideas and dont want to waste money.

Your expertise is most welcomed.......