That document is where I was looking before (although a different
link). My car is a *1987 Honda Prelude* which is the first row of the
table on page 16. That says:

"Procedure: Access ECU (located behind
driver's seat within door pillar assembly)
(H8). Turn ignition on and
observe LED on ECU for codes.
Codes: Codes blinked out by LED are
separated by two second pause, then
repeated. For example: 2 blinks - two
second pause - 2 blinks = code 2 (H14)"

No tool necessary it says. however, i don't really know how to get in
the 'door pillar assembly'