My mate just had 60k service done on his A3TQ at Audi dealer. The engineer said he needed a new "brain" for his Haldex system, just a £1500 job. This all based on a fault detected by VAGCOM, with no symptons showing. It's a tricky one to diagnose, as how do you tell if the Quattro/Haldex is working 100% properly? Presumably this "brain" is just a chip (or collection of chips), so how can Audi justify £1500 for a replacement (only 30 minutes to fit apparently). Anyone heard of this? Could the system be reporting a fault, even though it is working properly? I don't have the fault codes.