If anyone finds when attempting to start their 406sv (D8 models only) and the motor turns over but doesn't fire-up try this;

Remove key from ignition
Lock the car from the inside with the remote key,
Sit a wait for 15-20 seconds,
Unlock with remote key and
Start car.

If still doesn't start repeat above after that you are on your own.

I have attempted to get to the bottom of this problem but my peugeot mechanic (peugeot dealer)hasn't been able to locate anything, but it is common O/S.

good luck