Hi everyone. Every now & then when I start my car the immobiliser light above the clock flashes. Sometimes it stays on for about 30 seconds, sometimes a good 5 minutes. It seems to start flashing quickly then slows down until going off. It has never affected the starting or performance of the car & happens with both keys. I was just wondering whether this likely to end in a non start one day & what the likely fault is. I'm thinking it may be the key transponder reader (which I'm guessing is in the ignition switch), but surely if this was faulty the engine just wouldn't start. Your thoughts would be appreciated.

That light is the PATS light (passive anti theft) The light flashes like most cars to tell you the system is active. As in you cars security system. That light tells you what the system is doing and flashes a certain number of times to tell you that there is a fault with the system. If the system is functioning normally the light will flash every 2 seconds when the ignition is switched off it should be solid when starting the car and go out if its flashing theres a fault either theres a pats issue or in some cases it can also indicate the alternator is failing

If you watch the flashes it will be repeated a few times. Record the code and you can find the flash codes on the web. (pats immobiliser flash codes on ford wiki)

I can't post the link as its blocked on this forum.