I have an OBDII scanner that won't connect to my Honda but it will connect to my dad's tacoma without a problem

 

Then the problem must be in the car. The wires to the obd2 port may be shorted, or the main computer has a problem. You can always take it to an AutoZone or other parts store and see if they can read anything - its free.

 

Yep - same for me and my 1998 Accord. The OBD connector under the steering on the right is in two parts - the one you need to read is the 3 pin which of course is not standard. I manage to modify an existing adaptor and it worked. The adaptor (3 pin socket) was bought off email and i can let you have the wire connections. It may just work for you !