This question is an exact duplicate of:
I had already posted a question on this but today I finally checked my DLC connector. I got some bad readings. I checked between pin 2 and pin 5 key off. .29v then checked with KOEO got 1.5v. I then checked the pins individually neg. lead to ground. Pos. lead to pin. Pin 2 .3 to 1.8v. Pin 4 18.2v. Pin 5 12v. Any Idea on what to look for. I'd hate to have to take it to the dealer again for this issue but. At least I got an idea now. Its not a ghost in my truck. This is on a 2005 Chevy Avalanche K1500 5.3L Automatic. Also my OBD2 scan tool does not fully link when trying to get codes.