I have a 2000 Honda Accord LX Automatic with 130K miles. A few months ago the D4 indicator started flashing intermitently and would stop when I turned off ignition and start again. My mechanic claims that transmission would have to be replaced. That was 7000 miles ago. Most of the times D4 flashes when driving in the city with speed below 40 MPH, but twice in the last few months, it happened on the freeway, and I noticed that the card would not shift to 4th gear. As soon as I would turn off the engine and restart, problem would go away. I would like to know if this is a some kind of a sensor problem or transmission is on its last leg.

I suggest you take it to a REPUTABLE transmission shop. I suspect it is a sensor or solenoid problem. The flashing D4 is the transmission controller sensing a problem. If your mechanic did not or could not scan the controller, then you need to take it to someone who can. With the sophistication of modern tranmissions, a simple bad connector or blown fuse can shut down the transmission.

Let a transmission shop scan the computer and see what codes come up. That flashing D4 light is telling you that the transmission computer has picked up a problem. You must scan the computer to see what problem it has found. Let us know what you find out. It could be something very simple as a speed sensor.


Do you recommend taking it to a Honda dealer?

The car is 8 years old with over 130K miles. The dealer can diagnose it and offer a fix, but you will pay more than a good independent trans shop. One of the dirty secrets is that car dealers usually will out-source transmission work unless it is a factory replacement.

Have you bothered to read what your Owner’s Manual says on this topic?

If it is anything like the manual from my '92 Accord, or either of my Subarus, it says something along the lines of “a flashing D4 light indicates an electronic fault in your transmission. Continuing to operate the vehicle under these conditions can lead to mechanical problems”…but, I paraphrase.

In other words, you could have done significant damage by driving it for several months like this. I suggest that you seek an independent transmission repair shop (NOT a chain operation) that has been in business for more than 3 years or so, and have them diagnose the problem.

Quite correct, BustedKnuckles!

My neighbor had his VW auto transmission “rebuilt” at the dealer a cost of some $2000 after it failed. A week later I had the transmission of my Nissan in my neghborhood shop for regular serivice ($60). I meantioned the neighbor’s problem and he said his shop overhauled a lot of VW transmissions and the cost wa usually about $600-$700 to the dealer. I’m not sure if the service is exactly equivalent, but it’s best to go to the independent shop directly.

Yes I have and it says exactly what you said. I have to find an independent transmission shop in the area per your suggestion. Thank you.

cottman trans will scan it for free. I think the sensor is in side the trans mission. my friends maza had them in side and a $3500 bill
would fix it. trade it in