hey, just looking on the net and found this awsum link for VN-VP. It lists all the error codes, all the different diognostic modes.etc
I decided to place this post here and not the VN-VP section becaus this is got to do with HOW TO self diognose problems if anyone was wondering.
I found it a good read anyway...
http://www.techedge.com.au/vehicle/aldl160/vn_aldl.htm