I have 93 accord 10th anniversary addition 179k. The check engine
light  came on and the D4 started blinking at the same time. Checked
the codes and came back with  a 6 for the check engine light and 1 for
the D4 light.  Looked up the engine light code and it says that it is
the coolent temperature switch. I cannot find what the code is for the
D4.  In addition, recently the idle has been intermittenly high after
driving and then putting it into park. goes up to about 2k and
sometimes surges. Sometimes it goes back down to normal (800rpm) and
sometimes it does not. I  did clean the IAC screen and checked the
coolent level. I have also searched this news group about the D4 light
but did not find any clear info.  Any input would be appreciated.