Join Date: Jul 2009
Location: Top of the A303
First thing to check is that the keyfob battery is good and is inserted correctly. The immobiliser transponder in the keyfob does not take power from the fob battery - it takes power wirelessly from an antenna in the dash so will start the car even if there is no battery in the fob.
If the battery is good, and it is inserted correctly then the unlock switch in the fob is probably faulty. Does the fob unlock the boot?
If the switch is bad then it can be replaced - you'll need to get one from RS, Farnell or wherever and solder it in.
I replaced a switch in a 156 fob some years ago, and gave some spare switches to Adrian at Alfa Aid. All my 159 fobs have been ok so far so had no need to open a 159 fob.
I think there is someone on here that does repairs.
Alfa 159 ti 2.0JTDm
ex. 33 1.7 16V Cloverleaf, 156 SW 2.0JTS, 159 1.9JTDm