2002 Honda Accord V6: FLASHING D4 Main Relay

I was driving home from a relay hot summer evening and my gave me a check engine light and the D4 was blinking. On top of reviewing and check the check engine light I will also check the main relay for this Honda. The main relay can either have a short, break, bad welds but in my case the brass pieces where all corroded. Corrosion can be and is always an electrical nightmare for most people. Don’t try and clean in of brush it of especially on smaller components because this will generally make things worse. I did and it just replicated the problem again but I had a few other issues that in combination made for this car to idle high, bring the rpms to high and a drop in speed when the RPMS went above 3. I hope 🤞🏽 this break down helps someone with a 2002 Honda Accord. I don’t have this vehicle anymore but this is one of my most reliable daily driver I have ever owned. 😊🚗☕️🔧 #hondaaccord #HONDA #2002Honda #2002HondaAccord

[@KristianJernandez]

So much good information. Thankx!

[@godschild138]

My d4 light won't come on if it dont my car wont start....im tryna figure out what controls that i use to tap underneath an it come on

[@drumtwo4seven]

Damn Good 👍

[@viking0073]

my car has this same issue unfortunately no competent mechanic in my country.

[@ViinceDollarsz]

I’m dealing with the same problem

[@newb387]

I hope 🤞 this is helpful.

[@coleaydeesixxx]

Mine is in park but the D4 is also on. Now my car won't start. Any thing I can do to fix this? Thanks a million for the help 🙏

[@newb387]

If it won’t start I would start with the main relay but also check your battery 🪫.

[@coleaydeesixxx]

@@newb387 thanks bro, I went out this mourning. Still wouldn't start, I put it in neutral let it roll down the driveway and slammed on my break put it back in park tried to start it again and it did start. I'm gonna check what you told me to do. Thanks so much bro 🙏

[@tonyisaac8053]

My car will give some of the same codes but I can take off the positive cable and it will reset and run OK for a little and then not shift again

[@newb387]

Some electronic could be having a short and you just might allow it to cool of by taking away the ground. By not having ground you will not have a circuit with power once power comes on it might start to heat up and then stop working. Their are 2 shifting solenoids that could be failing, the CPU or the main relay. If you never serviced your transmission the solenoids also have a screen that could be full of debris and cause them to fail and not shift or final thing your transmission is going out. Just brainstorming with actually physically checking your car. I hope this helps you identify your issue and fix it.

[@bernardocisneros4402]

Bro, you should really take a writing class. I mean no disrespect, but it would help you a lot.

[@newb387]

I feel you homie!!! 😂😂😂😂0-100! My family always tells me that!

[@alonzovazquez1260]

Mine doesn't choke, but i turned it off and back on and it was gone, so idk what happened and why it disappeared, but the check engine is still on

[@newb387]

The D4 may flash especially on hot days. I would drive my car home right after work and it would flash on my drive home but in the morning when I would get up in the morning it would not. The main relay is a bad part the has welds that crack and a hot day may induce the D4 to flash. That is the main cause for the D4 but the check engine light could be a allot of different things. Run the codes and see what pops up. Then start fixing problems one at a time and troubleshooting is usually always different on a case by case basis.

[@alonzovazquez1260]

@@newb387 I got the p780, shifting malfunction, looks like gear 3 has problems, and its not the solenoids, also my transmission kicks, guess I need a new transmission, do you know a good site to buy them?

[@newb387]

@@alonzovazquez1260 I just take mine to a local transmission spot that only does Transmission and they will do full rebuild.I live in Washington state so the place I go to often is off I-5 exit 125 to the left of the 76 big giant red letters Transmission. I also check out any junk yard near me and compare if it’s cheaper but this project can add up really quick.

[@jbortega1178]

​@@alonzovazquez1260 did you ever get it fixed and what was it...

[@babyboi4778]

I did my own replacement of the transmission..an it wasnt the transmission check the speed sensor is where i would start ..

[@christianzamora7214]

Where did you get the relay from

[@newb387]

Auto Part or O'Reilly I got the cheapest one because of my budget. The dealership one was $200ish but if I had the money 💰 I would have chosen the dealership all the time. Their parts for 90% of the time are usually better.

[@MrCaBa69]

Should I scan the car first to give me the codes or you think i can start replacing the oil transmission to see if that fix my because is happening to me the same i never changed it has 123000 2002 SE Accord

[@georgediaz34]

Funny enough I have the exact same problem and same miles as you 😅

[@newb387]

I would start with the transmission oil. If you have a check engine light. I would pull codes as well.

[@georgediaz34]

@@newb387 update: changed the transmission fluid. Still rough, but is shifting smoother than before.

[@newb387]

@@georgediaz34 When your driving do you hear clunks when the transmission changed gear ⚙️, a vibration on your steering wheel or any other noise windows rolled up? Also what’s the mileage of your vehicle and when you where getting the flashing D, was it hot or cold?

[@georgediaz34]

@@newb387 so after I flushed the fluid, I no longer get the flashing D anymore. Usually when it flashes d it means it’s low on transmission fluid. In regards to the clunks while shifting I’ve had none loud one, shifts almost normal now after 150 miles of driving on the new fluid. Mine has 127k miles.