When I shut the tailgate this morning, the alarm went off, Locking/unlocking it didn't stop it, and it get going even when I started the car! Luckily, after four cycles it stopped, and seemed fine afterwards. Locked the car at work and all was fine, but then the exact same thing happened when I cam to go home. As it coincided with closing the boot, I wondered if it was maybe a microswitch, or tailgate hinge wiring issue, but I seemed unable to replicate it.
A scan showed code 01134
01134 - Alarm Horn (H12)
01134 - Alarm Horn (H12): No Signal/Communication
- Anti-Theft Alarm sporadically triggered
- Fuse(s) faulty
- Wiring and/or Connector(s) from/to Alarm Horn (H12) faulty
- Alarm Horn (H12) faulty
- Check Fuse(s)
- Check Wiring and/or Connector(s) from/to Alarm Horn (H12)
- Check/Replace Alarm Horn (H12)
Then halfway through the evening it starts randomly going off and won't stop at all, so I remove the siren from the car. Tomorrow, I'll cut it open and see what's inside. Possibly just the batteries have gone, but I haven't had any of the telltale three beeps etc. Maybe the batteries have just leaked and killed the PCB.
I'm assuming it's not a microswitch as nothing is showing on the scan, and the DIS shows the boot as shut, and presumably the siren would stop when you disarmed the car?
Anything else I'm missing?