Hi, I've had this issue since last year (1993 E34)!
don't know what car you have though.
The cable's a start. if you read my problem, the ABS, speedo and cruise all worked ok, if they don't then I would think
that a wheel sensor is likely to be the issue. Have a read http://www.bimmerwerkz.com/forum/index.php...opic=13433&st=0
and see if anything helps - Mine turned out to be simple, after a lot of expense cleaning MAF (and killing it), changing the throttle position sensor (which is what the original diagnostic said the problem was!), etc……