Hy... my grandfather owns a 91 accord... sometimes when he is about to start the car the d4 lights begins to flash and his car doesn't want to star, when this happens he waits for serval minutes to pass and then tries again and his car sometimes starts..... this doesn't happen every time but happens sometimes in the same week..... I dont know to much of automatic transmissions so please help me out and be very specific.... I only know of manual trans so please help me out.... thanks for all your help you can bring me!!!!!

 

The d4 light flashing means the transmission computer is detecting a problem and stored a code specific to that problem.

What you need to do is get the code. Use a piece of wire or a thin paperclip to short the blue two-pin connector behind the passenger side kick panel. Turn the key to the II position, and count the D4 light flashes. A long blink=10, short=1, so LL SSS = 23.

See: techauto.awardspace.com/dtc.html

Here is a video as well: youtube.com/watch?v=b6rEk9aXOmg