obd connector

tried to get a state inspection and the obd connector will not communicate with the computer, any ideas on what might be wrong. and what i can check to fix it.
:banghead:

assuming your vehicle is 96+ OBD-II

go to autozone or another parts store thats pulls codes n/c, confirm their scanner can't communacate also, if it can communacate, retest at a differant test center.

check for two grounds (pins 4 and 5) and battery power(pin 16) at the connectior, seen here - http://www.obdii.com/connector.html, if those are good, check the wire from OBD connect pin 2 to the PCM, if everything checks out ok, the PCM may need replaced.

Thanks for the reply, I will look and make sure that all of these things are working.