Hi guys.. I have a similar problem I recently (9-10 months ago) bought a 2006 S60 D5 185hp...
Every now and then I get the 'anti skid service required' in the message window with no apparent change in performance.
Switch the car off, pop into tesco for half an hour, come back start her up and message gone...
The message might pop up once a day for 2 or 3 days then nothing for a month.. It came up once or twice immediately after a fairly hard launch hoofing away from the lights .. But now I'm worried that the MOT is due in a month and with the new test rules saying any lit warning light is an instant fail, and I've heard a few horror stories that fixing it can empty ur bank account....
Any advice gratefully received
