In May this year our 52,000 mile 2006 Mercedes CLS 320 CDI suddenly stopped without warning with the ignition switching itself off and the key rotating one position anti-clockwise. This in turn shuts everything down. The car was returned to the garage for diagnosis and repair but no fault showed up on the diagnosis computer. This cut-out has now happened seven times and the car was back with the garage for two weeks for further investigation and testing without this intermittent fault reoccurring with their mechanics.

The ignition key was exchanged for the spare in case the key was the cause, but the cutting out continued. The crankshaft sensor was replaced to no avail. Now it is suggested that that the ignition E.I.S. control switch could be replaced at a cost to us of some £800 plus labour, but no guarantee is given as to the correction of the fault. Have you come across this situation before? Apart from the danger aspect to ourselves we are concerned about causing an accident involving others. Driving the car as it is puts us in an invidious situation with our insurance company as you will appreciate.