Thank you for your reply.Very kind. I am not technically minded so I do not fully understand what you are asking. Please can you give some more information. What I can say is the engine stops with all the dash lights on, I turn the key to turn ignition off and then restart the engine, all fine again. It has happend 4 times in 500 miles. Thank you so much for your assistance.

no reading when turning the key means no crank angle sensor signal so no probable Crank angle sensor fault.

Should read:

no reading when turning the key means no crank angle sensor signal, so probable Crank angle sensor fault.

Kettrell: note that a faulty cps often does not result in a mil code, for the simple reason that without the cps signal the engine's ecu simply doesn't know the engine is turning. So, if you get this problem, get the codes read ideally within 10 ignition cycles and if there is no code , suspect the cps.

The engine ecu will usually clear any non recurring fault codes after a set number of ignition cycles, this number varying from manufacturer to manufacturer. This is why people who get a mil and get their codes read a week later often find there is no code!

Or you could download something like Torque for Android and buy yourself an EBD Bluetooth adaptor and read it yourself the next time the problem occurs. Torque is about £3 and an adaptor about £25 - so about half what many dealers charge for code reading once. You can use your own again and again!