Honda Car Forum

My husband drives a honda accord and everytime the D4 light starts blinking his car will not start. Does anyone know what it could be? We took it to Honda and they did like a computer scan and charged us $80, and they said that it was a hard coad imbedded into the computer that they went ahead and erased. It was running fine for about two weeks and now it's doing it again. What could it be! Some people say it's the transmission, some say it's the computer, some say it's the fuel pump relay. But all those things are really expensive to jus try, and no one will tell us what is wrong with it! It runs perfectly once it actually strarts though.. Please if any one knows honda's, can you help us.

disconnect the battery then reset car if problem stays go to oraily free check out on lights and problems save 80 .oo

Yeah I agree with the other guy here. That is exactly I would do.

The D4 light typically indicates a problem with the automatic transmission control system. When the D4 light is blinking it means that a fault currently exists in that system. That light can be triggered by any of the monitored components, including the transmission control unit, the shift indicator switch or any of the inputs to the control unit.You didn't mention what the code was that the dealer retrieved. If you could get that information ti would be a big help in diagnosing you problem. My gut feeling is that the problem is with the shift indicator switch that "tells" the control unit that the vehicle is in Park. There is a switch called a "neutral safety switch" that will not allow the car to start unless its in park or neutral. If that switch is bad you won't be able to start the car and the light will flash.How does your husband get the car started? If he has the problem again, ask him to take the car out of Park and to try to start it in Neutral. That may overcome a problem with worn contacts on the gearshift switches.the main relay for the fuel pump that people have told you about is a condition that occurs when the car is parked in the sun an the interior temperature rises. The main relay problem will not cause the D4 light to come on. It would also be extremely unlikely that the transmission control unit went 'bad' after 15 years.The problem is most likely caused by a loose connection somewhere in the starter control circuit of the transmission control unit or a switch (range selector or neutral safety switch) that has worn out over time. Hope that helps

I can almost guarantee that it's the main(fuel pump) relay.A new one at Honda is probably less than $50 or you could get a used one at a salvage yard for real cheap and install it yourselves.You can find a picture of it at slhondaparts.com. You might however,need a transmission computer,which you can find a cheap used one at car-part.com