JAMAS, are you any good at soldering? I've found some info on BOSCH ABS modules malfunctioning in AUDI and VW (BOSCH 5.3).
http://www.youtube.com/watch?v=UqtowdSDbxU
http://forums.qrz.com/showthread.php...sch-5-3-Module
I'm not sure how closely our module's electronics match the 5.3 unit (produced in the late 1990's, but there is a good chance that our issues are as simple as the silver wire breaking as seen in the german cars listed above. If you would like to try to open your spare up, you may be surprised at what may have been the issue all along.
Joseph
I may open mine up this spring. I find that the cold allows it to function sporadically.