2009 Pilot No OBD Communication
 

Hello All,
New to this forum and have not figured out the search option well.
Have a 2009 Pilot with 100K miles. Came home from 1 week vacation to find battery dead. Tried to jump start but alarm went off when hooked charger to battery.
Pulled battery and charged out of car. Reinstalled and started fine and no issues since then.
Received notice of emissions test and tried to check for codes but both my scan tools say no communication through OBD port. Checked all fuses, all look good.
My mechanic said it would be cigarette lighter fuse but with key to on position, I read 11.9 volts at the 12 volt accessory outlet. When I start car, it reads 14+ volts.
Not sure what else to check. Any input would be appreciated.
Tim