engine management and gearbox trouble

I have an 03 plate ducato 11 2.0 jtd, when at speed on the motorway engine light comes on and engine cuts out. i then pull it over to the hard shoulder turn the key to the off position restart it then it starts fine. it has done this about 5 or 6 times in the past 2 days any ideas?
Also put the van into reverse yesterday and could not get the thing back out of that posistion it would go into neutral with a little effort but the gear stick remained over the left hand side of the box, if that makes sense? allowing me only to select reverse or stay in neutral.

Any info? cheers

a diagnostic would be helpful here,but crank sensor/injector wiring/throttle fault springs to mind.

Still no nearer to finding this problem with the engine managment light, had diagnostic done by the AA and it comes back no fault.
It has been in a fiat main dealer now for over 2 weeks and they told me it was the EZR valve that was at fault which resulted in the airflow meter breaking.
They changed all this and still no good. they thought it could be the fuel pump does this sound right?

Hi,
i had the same problem twice with a 2004 2.2 hdi citroen relay. under 2500 revs no problem, as soon as the revs increased, the warning light came on and the engine cut out. pull to the side of the road switch off, restart and off you go again.
The first main dealer wanted to change the injectors and fuel pump, nearly £3000.
i took it to a second main dealer (in Chelmsford) who immediately diagnosed a faulty injector, 24 hours for new one to arrive and back on the road. a couple of months later same problem, same diagnosis, different injector replaced and van has run fine since.

hi did you ever sort out the problem if so what was it as i have an 04 plate 2.8jtd doing exaclty the same thing