I have a 2008 SX4, 1.9 DDiS (yes, I know.......).

Stopped to fill up with diesel and when I got back in it wouldn't start. Turned over perfectly well, just would not fire. The blue light flashed every time I turned the ignition on suggesting that the key was recognised, but all signs were that immobiliser was stopping the engine firing.

I left the car on the forecourt and walked home to get the spare key. By the time I got back, the garage had jumped in and started the car without a problem????????? ( I did leave the key with them)

All been fine for 2 or 3 weeks until today. It had been started at least 3 times today, then went into a shop for 10 minutes, came back and no start. Left it for ten minutes then tried again and away we went and has not been a problem since.

Any ideas please?

Crank sensor.

MIL light finally came on.