Hi guys, I'm hoping someone can help. Whenever I lock my ST220 the alarm keeps going off. Well when I say that it's the indicators that flash, as I'm guessing the previous owner took out the siren to stop it annoying them. Now when I got the car the bonnet didn't sit down properly and I thought it might be the bonnet catch/switch, so I replaced that unit. I've subsequently found it wasn't that and the bonnet closes properly now.
When I put the scanner on the car it's showing door ajar codes for all 4 doors, and it won't let me clear the codes. But I can't think that it would be all 4 doors that would be a problem?

Anyone got any thoughts on what it could be or more tests I can do to track it down?

ps the central locking/remote locking works all the doors correctly, and the boot will lock and unlock on the remote too. The passenger front door does stick a bit when you try and open it but I've already replaced all the mechanism in there once because of that, although bizarrely it doesn't seem much different.

Any help or thoughts gratefully received as it's driving me bonkers.