I've checked through the archives and similar faults are listed on there mentioning ECU problems. This one also has an intermittent starting fault. I've only got it to reproduce the fault once in the five times I've looked at this car. I didn't have time to check the immobiliser function before it restarted. I know the engine management light comes on and doesn't flash, I don't get comms with the engine ECU and the cooling fan runs on slow speed. The customer says it can take up to half an hour to start it sometimes. Before I book it in with Vauxhall for a new ECU, I thought I better see what you guys think. Cheers.