Just to clarify (my initial post), my mechanic has a thick polish accent and I can't always understand him. However, I'm certain the error code (below) is correct because he wrote it down. The narrative may be off a bit though...

My mechanic pulled the ECU diagnostic code, "0030711727_A" from my 2005 S40 T5 today and can't read it. From what I understand, his machine can't read the code because VOLVO won't share the interpretation with the manufacturer. Can anyone help?

 

That looks like nothing I've ever found. Do you have an Autozone or Advance or similar near you? You can have them pull the trouble codes for free. The diagnostic port is down by your right knee just past the plastic enclosure for the center console. All you do is ask the person behind the counter for help.