I have a 1992 Honda Accord LX. It has had several DTCs for the
automatic transmisison set for quite some time (approximately two years
for at least 3 of the 4 codes). There didn't seem to be anything wrong
with the car, so I didn't worry about it. The D4 light blinks only
when the test connector is shorted. I didn't even realize that these
were DTCs for the transmission until recently. Recently, the car has
started to shudder on accelleration (or under load, like when
performing a stall test) between 1500 and 2000 RPM. (It feels like
you're going over small ripples/bumps in the road.) It occurs almost
exclusively in this RPM range, although it has begun to creep up into
higher RPM ranges as the problem has worsened. It is very hard to tell
if it is a sputter (engine) or a shudder (transmission). There does
not seem to be a sputter in the engine when giving it gas while in park
(or reving the engine freely through the specified RPM range). I do
not have the service manual for the car (though I have been meaning to
get one). The codes are 1, 2, 7, & 8. I do not know if these are long
or short blinks because they are all the same duration with the same
duration pauses in between. I would guess that they are short, based
experience. Can anyone help? I would appreciate any help possible.