I have a 92 honda accord 2.2 automatic and my d4 light flashes all the time we tried changing the vss and that didnt work. Also it takes off great but second gear is sluggish other gears are good too.

 

Behind the passenger side kick panel, there is a blue 2-pin service check connector. Jump the connector with a wire or small paper clip to retrieve any stored trouble codes by counting the D4 indicator flashes.

See this link for info. on retrieving and counting the flashes.

Honda Electronic Transmission Problem- Troubleshoot, Inspection, Repair, Replace.

Blown or burnt capacitors and/or resistor were relatively common in the Transmission Control Unit (TCU) for your generation Accord with automatic transmission. Info. is also in the same link.

 

My Dad had a 92 Ex that did the same thing once in a while. His ended up with over 260K but the blinking never seemed to affect anything. I have used Slick50 high mileage trans fluid in my 2000 civic and it did make a noticeable difference