I have just purchased an s80 v8. It has a few miles on the clock and some minor issues which are easy to resolve. However it has started to throw up a message of immobiliser fault on occasions at which point it will not start. I have scanned it and it comes up with multiple communication errors for the ecm. I have checked the ecm and there is no water damage or or obvious issues. I have a launch code reader but no volvo specific stuff. Can anyone suggest what I should be checking for. Are there known faults to check first. Car is a 2007 s80 v8. I can diagnose things myself but just need some help to start as I have never dealt with volvos previously. Thanks Mike