Mine's a D1-30B which was 2006 - 2008 as far as I can make out. The original D1-30 engines had a manual switch located so that the engine could be stopped in the cabin but the later models don't seem to have it, or, if they do, it's not marked as such. However, the D1-30 series must all work in the same way. I'm at the Boat Show next week and will speak to the Volvo engineers there. I'll report back on what they say.
fyi - a friend is currently travelling (single-handed) back from Ireland and hit bad weather and an underwater object just off Lands End. Although he's ok, he fell and broke the engine switch and can't turn it off at present