First post here! I've owned a 2000 Accord EX with AT for over 20 years now. Had very few issues. I enjoy staying on top of maintenance, but had first major issue with my Accord. I guess the transmission are notorious for issues. I must be lucky because I am at 206,000 miles and the transmission recently started throwing codes and acting up. Had one transmission specialist look at it, said he'd need to open it up to know more and it would likely be in the ballpark for $3000-4000 when all is said and done. More than the car is worth.

Symptoms are that it is often slipping out of first into neutral at stops, hard shifts from 1 to 2, and flaring between 2 and 3 (revs up a bunch of RPMs before shifting). Once in 3 and 4, its very normal. Occasionally a hard shift causes the D4 light to blink. D4 light sometimes trips while not moving too, often when stopped on a hill (uphill). Still drivable but real finicky.

Throwing these error codes regularly: P0700, P0720
Occasionally/rarely throwing these: P0730, P1738, P1739

I just replaced the input and output speed sensors, as well as the ATF Pressure Switch (I think also called the 2nd clutch switch). No real improvement. Tried resetting the ECM twice by pulling the battery. Was told by a neighbor mechanic that the ECM sometimes needs to relearn the new sensor behaviors.

Wondering if anyone else has experienced or solved a similar issue apart from rebuilding/replacing the transmission? Am I wasting time thinking it could be sensor or ECM related? FWIW I've stayed on top of the fluid for many years. Been very diligent with drain and fills. Used Lubegard red too for at least 7+ years.

This is somewhat irrelevant but I was given the car by my grandfather when he passed in 2005. My 15 year old daughter would love to have it for her first car for that reason, but that may not be practical.

 

Hey I'm no engine expert but I can tell you this. You're better off saving yourself a good amount of $$ by looking for a low cost, low mileage JDM tranny to swap with.

That's exactly what I'm doing with my '95 Accord LX, a generation before yours that had the much more reliable trannys. It's in the shop now but taking a while only because I'm doing a complete engine + tranny swap. My tranny was still running OK at 255K+ miles, just started making loud noises in reverse (probably damaged and my fault) but it wasn't worth the cost to try to repair/rebuild it. My mechanic tried to get it quoted and it was repeated that parts are so hard to come by w/ such an old tranny.

I'm not saying you can easily find a good deal but I got both the JDM engine + tranny for just $1600. You just have to shop around. Figure the tranny is worth half of that and then you have to pay labor but you can see it can easily be half the cost of what you were quoted. There are enough JDM seller nationwide that you can pay for the ~$350 shipping that you'll still come out on top. i.e., https://www.jdmwestcoast.com/product...ion-only-98-02

Plus they will be low mileage... and it's not a scam because of "Japan's strict vehicle inspection system known as the Shaken Law. At the 100,000 km mark, cars in Japan are required to undergo a comprehensive inspection and maintenance overhaul." Most of the time, it's not worth to keep so they get sold to their secondary market and make it here stateside.

 

V6 or 4cyl?

I would get a second professional opinion if you genuinely intend to keep the car. There is plenty that can be done to diagnose and find or narrow down the cause without jumping to opening it up. In my experience that's code for "I don't really want to work on this but I'll take your money if you really want me to."

this may be an issue with fluid flow like an internal blockage or fluid pressure maybe from a worn pump, internal leaks ect. a pressure test could say one way or the other. If you can't find a PDF copy of the troubleshooting procedure for the codes listed I can try to relay highlights from my hard copy.

 

4 cylinder. That seemed to be EXACTLY the transmission shops attitude.

I forgot to add, the transmission is fairly normal on the first 5 minutes of the morning drive. Like it is a pressure thing related to the fluid viscosity or temp. I'll try to google the troubleshooting procedure PDF. Never heard of that but sounds helpful.

 

Take the automatic transmission and all that is involved with making it work, out. Find a recycler, turn all that junk over. Take the money and use it to purchase everything you will need to install a manual transmission.
You should be much happier, you will never have to worry about that really bad idea called the Automatic Transmission.

 

That might be an idea for enthusiasts (even I just opt for the AT for any city/traffic driving) but it's for his 15 yr old daughter learning how to drive so likely not a good option.

 

Did the trans specialist take pressure readings?

Since this all seemed to occur all at once I would suspect an electrical(harness) issue rather than multiple mechanical issues.

Check all your grounds and bonding jumpers are still clean, intact, and tight.

Was there any recent work done?
Any recent incidents with the car?

 

Thanks, @MAD_MIKE

I don't believe he took pressure readings. Definitely did not report them if he did. Simply restated the symptoms I already reported when dropping it off. I can't emphasize enough how disinterested he seemed.

No recent work done or incidents. I will look into where ground and jumper connections are.

In a strange turn of events....the car has started acting completely normal the last 3 days. No slipping in 1st. Very responsive. Some mild flaring from 2nd to 3rd still but nothing else.

My neighbor is a mechanic and said when we changed the sensors it can take a few weeks (up to a month) for the computer to relearn the new sensor behavior. Maybe that's actually the case? He also recommended the Lucas Oil Transmission Fix in the event that its a pressure thing. The AT was more normal when first starting up and the engine was cool. Thought the thicker fluid might help increase pressure, albeit a temporary fix. So I did that a week or so before my first post.

 

On the 98+ ATs there is a 'linear solenoid' that can be adjusted but needs a pentagonal hex drive and several pressure gauges to monitor all circuits.
A competent mechanic can do the adjustments.