Now that I have got most of my electrical bug's out of this car, I run into this! @#!@%!!! LoL. It's a 1992 Accord LX. The car drives great! accept when the D4 starts flashing. Then it's like trying to drive a car with a badly fried clutch, but only in forward gears, reverse is still strong. Now when you turn the car off, and start it back up right away, the flashing D4 is gone and the car drives normally again, good and strong, with firm shift's in all the gear's. Can anybody tell me what this flashing D4 mean's? or is this another electrical issue?. It really does not feel life a mechanical problem, but i'm not sure. This is my very first automatic honda, all my other's where all 5 speed's!

 

My 91 used to have a flashing light relating to the transmission. Turns out mine needed a speedo sensor. My problem was solved.

 

Take it to Autozone or Advance and get the codes checked. The transmission computer is detecting a problem. If the D4 light is lit even when the car is in park, or any other gear, your computer may have gone out. But get the codes checked, then come back with the results.