My d4 light goes out from time to time, transmission seems to drop out of drive when it happens, just does it for a second then runs fine for a few weeks and does it again, I jumped out the service connector and turn on the key, the service light does not flash it stays on when connector is jumped, does that mean there is no code set in CPU. 1992 honda accord dx

 

When you jump the connector, what is the D4 light doing?

ECU codes flash the CEL

TCU codes flash the D4 (S light if you have the "sport" option)

ABS codes flash the ABS light (if you have this).