I have a Fiat Ducato motorhome: 2.2litre 100bhp, 2007. I drove it 300 miles from North Yorkshire to a campsite near Canterbury (stopping a couple of times en route and also achieving 35.4mpg). Next morning it refused to start. The engine was turning over but never fired. Battery has plenty of life in it. I called out the AA and the patrolman diagnosed a fault with the immobiliser as the warning light was on. He was unable to cure it and so we were relayed home. Does anyone know of how to fix this?