it's a 91 right ? Yhen it's a 4g and i'm an expert in that. I'm too modest
Back to business:
There should be a connector between the dash and the door on the passenger side. It is kind of hidden and taped if nobody worked on it. He should take the connector out, short the terminals with a paper clip put the key in the on position on the ignition and the ecu should spit out the codes. Here is the link for the codes and how to read them:
http://hondata.com/techecucodes.html . For the speed sensor it should spit out code 17.
P.S. Tell your friend to get his ass on HS. Ya knew new members are welcome, and we need more accord guys here.