Started the car and it would only idle - no response from accelerator pedal. Turned the car off and on a few times and the same each time. I disconnected the battery for half an hour to see if it would reset the ecu in case it was running on some sort of safe mode but this also didn't do anything and the engine management warning light was still on when the battery was reconnected. This fault has now cleared but any ideas why it happened? The car was out of action for 5 hours so need to get a fix for it.