Locate the 2 pin diagnostic connector behind the glovebox door. (Not the 16 pin OBD connector which is on the driver side). Hook a jumper wire from one terminal to the other. Turn the ignition on, but do not start the engine. Count the number of flashes the D4 light makes, looking for both long and short flashes. Respond with the number, and I'll post the diagnosis. (there are more than 40 possible codes, too many to list here)
The D4 light on a Honda Accord is the transmission warning light. These come on when there is a malfunction on the transmission. For the problem to be diagnosed properly the vehicle should be taken to a dealership.
It's the transmission computer.you need to replace it.
WHAT DOES "SRS" LIGHT ON 2001 HONDA ACCORD DASHBOARD MEAN AND HOW CAN YOU PUT IT OFF
transmission trouble for sure
Replace your AT Control Unit (Automatic Transmission Computer)
The D4 light on a Honda Accord is the symbol for the 'check transmission' light. This light appears when the computer senses something wrong in the drivetrain. The computer should be diagnosed at a proper repair shop in order to source out what exactly is causing the problem.
Indicates a problem with the automatic transmission. Seek professional help.
How do I troubleshooting the D4 blinking on 1993 Honda accord LX ?
Problem with the A/T seek professional help immediately.
It means you have a problem with the transmission. Take the vehicle to a trusted transmission professional for repair.
D4 on an automatic and 5th gear in a manual.
It means there is a problem with the A/T. Seek professional help.