1991 Honda Accord flashing lite on dash

Hi tracker338, When the D4 lights starts blinking while driving, an error has been detected by the Transmission Control Module and you need to retrieve the Diagnos Trouble Code to find out what is wrong. Generally it should be a sensor out of range or faulty. Is the speedometer working correctly? Use a jumper wire or paper clip to bridge the SCS (blue colored 2 pin connector, it is taped to the wire harness ) terminal and turn the ignition switch to ON. Count the flashes on the D4 light and let me know how many. Long delayed flashes = 10 and short fast flashes = 1. The code would repeat once all the codes have been read.