it is no good saying it could be an ecu and just guess as it could end up costing a fortune,if the garage is a main dealer then they should have Tech2 to help through the fault finding,have they encountered any fault codes?any management lights on?have had a couple of fault codes on these relating to swirl pipes in tank and both times this happened the fuel level was very low,sorry cant remember if the vans were cutting out but did bring on management light,filled up and no problems since,there again this is just guessing so would go back to them and ask if they have found any fault codes etc,if they didn`t know if these had a chain or belt then that would not inspire confidence and would think about finding someone else to help you out.
cdc
July 2011