how can i fix cruise control on 2001 bmw 325 coupe?

I have a 728iL 2001, cruise switches on SOMETIMES at idle and then around 90kph shuts down, sometimes restart if you park and switch motor off, often doesn't - ABS doesn't work, tried sensors and all after computer reports, didnt help, any ideas? iokazmi[at[gmail[dot]com please - am based in Dubai DO NOT want to sell it, but without cruise and a rather bouncy rear suspension will switch in few days to a 10 year older LS 400... worse all round but easy cheap to fix...

Imran O Kazmi
December 2013