Join Date: Jun 2001
Location: Bergerac, France
Could be the cam phase sensor, but whatever sort of phase sensor it will measure the position of a rotating part. As for the sending unit? could be an amplifier for the sensor, but to be honest the description from the garage sounds awfully vague like they don't know what the real problem is.
I would have thought that by attaching an ACR (Advanced code reader) they would be able to pinpoint the problem.
You might want to think about an independant specialist rather than a dealer, the rules have now changed, as long as any repairs are carried out using genuine Alfa parts, your warranty is safe.
If you do go down the specialist route, speak to TNi motorsport (don't worry they do regular cars) who are near to Brands Hatch, so not that far from you.