Data link connector not working. Scanner says tool not plugged up!

Check the fuses. You most likely have a blown fuse. Several manufacturers use the lighter fuse as power for the DLC.

Check your fuses.

I just had an '02 civic that had the same issue ...Not the connector or the fuse(s),the PCM had failed. Might be less expensive to have it diagnosed or get the proper info to test the circuits yourself with a good multi-meter not a test light.