Hi, can someone help me with a problem I have with my 1986 Accord

I recently took it into a Honda dealer and they told me I have a Code 3 warning on the computer.

Does anyone know what a Code 3 warning means please? The car also has a few other problems and I believe that this may be causing
these too, but I can't say for sure till I sort this out.

Problems like:
Idling too fast,
Weird behaviour with the transmission Lock Up System.

All assistance is greatly appreciated,
and thank you for your help.

Cheers
Mike the Kiwi