When i first bought the car, a 51 plate 3.3, i noticed sometimes the alarm would give one chirp when the remote button was pressed, but more often than not it wouldn't, but the doors locked fine and if a door was opened using a key the alarm would sound. Suddenly it gives one chirp more often than not and then around ten seconds later the alarm goes off. I noticed today that the alarm warning light by the clocks doesn't always flash when the alarm is set, but today it does and the alarm didn't go off. When it's disarmed after sounding it doesn't give a certain number of chirps to show where any supposed intrusion might of been,if it's supposed to. The bonnet pin switch appears ok, and all the doors and windows are shut, (no children or pets stranded inside!)Is it possible to either reset it, or any ideas as to a common fault that might cause this? The only thing i did prior to this was disconnect the battery to put the EMS light out after changing a lamba sensor.

 

I'm not sure what year you have but I'm assuming older than 2000. Start with the key switches, they can cause many problems and if the alarm doesn't shut off with the key in the door, there is obviously an issue with them. Door ajar switches out of adjustment are another common issue with them.

 

Thanks for your reply. It's a 2001 model.

 

2001 the door ajar switches are built into the door latches, not as much of an issue with those.