The saga started when the Mk3 failed to respond to either remote as described in my last post in the thread about the CTEK battery charger.

The alarm went off when I used the key blade to enter the car and it couldn't be cancelled with the remote so I just had to let it run it's course. The siren stopped after a minute or so although the hazards carried on flashing for longer. It all went quiet eventually and I left the battery on charge for the day. After 11 hours I tried the remote but it still wouldn't work so I had to use the key blade to gain entry again and the alarm went off again. However the battery was ok as the car started straight away (keyless start). I took the charger off, closed the bonnet and door and tried the remote again to lock up and this time it worked and has been working fine ever since.

I have no real idea why it behaved like this other than maybe it somehow got out of sync. If any of you knowledgeable guys have any thoughts about it I'd be interested to have them.

may be it was to do with the charger been in use, when you had it on charge did the remote let you lock the doors on the car then ?

The remote wouldn't unlock the doors whilst the charger was still on. I didn't try locking until after I'd taken the charger off.

This is a known problem of the Focus MK3.

The unlock button of the key fob can not work occasionally. Some cars did have this problem more often than others. When the unlock button does not work the car can be opened using the keyblade. However on a car with a factory fitted alarm system this will activate the alarm. A workarround when the unlock button does not work is to press the boot unlock button on the key fob. The boot should still unlock and after the boot has been unlocked the unlock button on the key fob should work again.

 

This problem was solved by a software update of the BCM in approximately 2013. However most Ford dealers do not perform software updates during services unless there are problems. Because of this there are still many cars arround which have this problem.

Hi Wilco, that's interesting and worth knowing. However I think I tried to unlock the tailgate first, as I was intending to load up, and only then tried to unlock the doors.

If it happens again I'll definitely try the tailgate trick and see if I can get a software update at the next service. Thanks.

Edit: In my other thread (What charger?) Rick (Yog) has just suggested a reason for what happened. His explanation exactly fits the sequence of events so is virtually certain to be correct.