My Renault Scenic 1.9 DCi recently cut out when being driven out of the local supermarket car park. It could not be re-started and the AA was summoned. The AA man suggested that the problem was likely to be a camshaft sensor, apparently a common fault on this car. The AA transported the car to a local garage (not a Renault dealership, the nearest being 20 miles away) where it has defied all attempts to start it.

It has been there for three weeks, during which the camshaft sensor has been replaced and following several CLIP tests revealing other faults, the crankshaft sensor has also been replaced, as have the glow plugs. An outside auto-electrician has been brought in but has been unable to identify any fault. He has removed the ECU for testing, which revealed that it was working satisfactorily. Other possible faults of starter motor, fuel pump and battery have been considered but do not appear to be the source of the problem. All concerned are totally bemused. Can you offer any other possible solutions please?