I had this fault:
1 Fault Found:
01134 - Alarm Horn (H12)
004 - No Signal/Communication
Basically the alarm chirps with lock/unlock which were coded on didn't work and if I set the alarm off the lights would flash but no sound.
Purchased a genuine "new" (in quotations as it had a couple marks on it when it arrived) from china on ebay and had it fitted by my mechanic at the same time as a full service a few weeks back. Was plug and play and now functions correctly. Is in a riveted box above the driver side front wheel arch I believe. Mechanic charged me half hours labour for swapping it out.
Apparently the backup batteries in the horn unit corrode over time killing it off.
