I have a 57' plate Zetec S 1.6 TDCi fiesta.

When I try to start the engine the immobiliser light flashes constantly for a minute and then returns the flash code sequence 1-3, which indicates a key issue..

The engine will not start at all, it won't even turn over and no relay sound is heard. This problem has come out of nowhere and i do not recall dropping keys or allowing them to be damaged by water in anyway, I can only assume it is maybe the transceiver than is receiving a faulty signal from the key? They key successfully locks and unlocks remotely and also opens the boot remotely. I have no spare key.

I have switched the key to ignition pos no.2 4 times in 6 seconds and then pressed the unlock/lock/boot button on the key in order to make sure its still aligned with the car and it beeps to give recognition that it is tuned. But engine will still fail to start.

The battery is completly fine, fully charged (checked), all lights and components work as they are meant to. Has anyone had this issue before or anyone heard of this issue and can provide some assistance? Would be greatly appreciated, thankyou.

I would strongly recommend an auto locksmith.

It sounds like the transponder chip in the key has stopped being detected.

Your key has two seperate parts, the transponder which interacts with the immobiliser and the rcl circuit that works the central locking.

Neither part has any affect on the other so the ignition programming routine won't affect your problem.

It could be either the transponder chip is damaged or the immobiliser ring around the ignition barrel has stopped working.

The locksmith should be able to diagnose properly for you.