Hex+canbus for diagnostics

[Bincrafty]

Hi,

Just signed up as I bought a 2005 A8 4.2 quattro earlier this year. I like big cars and after having a disastrous Mercedes e280cdi thought about one of these. I test drove it and liked it. It had been fully serviced in its history but I knew of 2 faults, aircon was blowing warm and the car button did not work but they  provided a replacement console and that sorted that. it drove at first flawlessly however I had to drive it from my home town to Cambridge, about 250 mile round trip, and the weather was awful heavy rain, as I neared the destination the ebrake warning light came on. I pulled onto a garage messed with the ebrake switch by activating and deactivation and it went away.  Drove it home and again it came on and this time added abs and electronic stabiliser to the mix. Thought about having a a look later on. Started the car a couple days later and nothing no warnings. took it on another drive and low an behold on the return it came back. this time with light adjustment added in.

Now I have replaced the front discs and pads as I read a faulty abs sensor can cause this or faulty break light switch (to be replaced) came to the rears and found you need this ross tech hex/canbus to release the rear brakes then almost died as I found the price of this rip off bit of tech. to do this job I need this lead and software which will  cost as much as the parts!! Anyway just wondering if anyone in the newbury area has this or has a second had lead to sell, if you were to come happy to pay for diag service.

I know the motors work on the rear as today with eh engine off could apply the parking brake and heard the motors run and the parking brake light is on