Our Focus (2001) has developed an intermittent fault in that it won't start on occasions which seem to be when the ambient temperature (not the engine!) is very hot. The PATS LED which is flashing slowly as normal when you get in goes out when the key is turned rather than coming on for about three seconds. Everything is completely dead. After a while, which may be 5 mins to an hour or more, it does start, which I guess is when the car has cooled down.
It would appear that either the transceiver is not reading the code from the key or, if it is, the immobiliser is not getting the go ahead to allow the engine to start. It happens with both keys so I guess it rules them out.
We've had it in a main dealers who did a diagnostics check and, I guess as a result of that, replace the transceiver. A week later, on the first really hot day since then, the fault has re-occured.
Two questions: Firstly, has anyone come across this fault before?
Secondly, I can imagine the bill will start to increase, particularly if the PATS system needs replacing, etc. If this is the case, can I just have the immobiliser bypassed? I realise this reduces the security of the vehicle but I guess I could just wire up a flashing LED to make it look like its on as a deterrant - and there may be insurance implications.
Cheers, Pete