Never mind. We found that my ODBII port was damaged, causing a poor connection to the battery connection.

-Matt

I have a 2003 S40, but this is a much more generic question... I work for a company that makes a device that attaches to the ODBII buss and monitors the vehicle :D. Before attempting to connect to the buss (my Volvo was an ISO buss) we need to know if the engine is running, we determine that by look...

Having a similar problem with my 2003, no codes or miss fires but when I changed the plugs I noticed that much of the insulation is gone! Someone (it's used and I got it recently) has used electrical tape to fix-up a large section. I can't find a replacement harness anywhere, looks like I'll be manu...