1999 Dodge Durango Smog failed because of no communication

Hello,
I attempted to have my Durango smogged today. All of the emissions were well below the avg. (CO2=15.00/15.04) (O2=.03/.01) (HC=23/10) (CO=.07/.04) (NO=0/0). But my Durango failed the MIL part of the smog test. The attendant tried several times to get it to connect, but he said he was getting absolutely nothing from the diagnostic connection. He suggested maybe it was a blown fuse since the connector seemed to not be getting power. I have physically checked all of the fuses that I believe could be responsible without any luck. There is absolutely nothing fuctionally wrong with the vehicle. It runs like a dream and has been lovingly maintained. The check engine light illuminates at start up but then goes off like always. I am currently at a loss about what my next step to take with it should be. Any help or suggestions will be greatly appreciated. Thank you, Simon.