Hi all, sometimes when I go to start the car it's completely dead the mileage just shows flashing dashes and the immobiliser light flashes faster. Most of the time it will work after taking the key out and retrying 2 or 3 times sometimes I have to go back to it after 10 minutes. Some days it works fine. I've changed the fob battery as I didn't know if it was an immobiliser problem but no joy. I've tested the main battery and it's reading 12.4. Wondered if anyone had any ideas. Thanks in advance.

Hi Mark, it does sound like an immobliser issue. Your car key has a passive chip in it (does not need the battery in the key to work). When the key is placed in the ignition there is a transponder loop, normally around the ignition switch behind the trim covers which detects the chip in the key and reads its code.

The problem needs to be split - It could be a key problem or it could be a car problem. Do you have anyother keys for the car ? Also take your car key off the keyring and try it just on its own (detection of the key can sometimes be intermmitent with other keys on the same keyring).

If the problem still continues after trying a diffrent key then it's a car problem and more fault finding will be needed

Hi, thanks I will try the spare key I have for a few days to see if it makes any difference. 

You should also google, 'ford focus instrument cluster fault', make a cuppa and get a comfy seat!

I've just put a code reader on it and it comes back as a speed sensor fault so I'm also looking it to that.