ABS problems

[alanryerson]

Hello, all
I have a 1994 Passat GL 2.0 Litre saloon. The Abs has been driving me mad for the last year. When starting from cold, the ABS light stays on until I have driven 2-3 miles. If I then restart the engine, the ABS light goes out and it works perfectly for the rest of the day. The problem is worse when the weather is wet (as it is at present here in the UK). Last year I took the car to ny local VW dealerwho replaced the left5 front ABS sensor. The next day the ABS light came on again, so I went back to the dealer. They said the sensor was OK but now the rear left inlet valve was faulty, and the cure was to replace the hydraulic module at a cost of £1000. Needless to say, I walked away!!! As I was driving back from the dealer I found that the ABS light was coming on when I ecxceeded 20 mph. When I got home, I found that the 4pin multiplug to the hydraulic module was disconnected. I reconnected it and problem solved, or so I thought. I`m still left with the ABS being temperamental, and I don`t trust my local VW dealer. I know that when the ABS light is on, the ABS system is not working, as I have managed to lock the wheels when braking hard. Any ideas would be gratefully appreciated.
Kind regards
Alan Ryerson
Stafford, England