Hi guys, I have been all through the topics and cannot find this exact problem, although there are hits all around it. Hopefully someone can help.

1992 Accord, transmission started slipping out of D4 at highway speeds, engine revved really high. Here's what's been done:

Transmission fluid completely changed, shift solenoids checked, verified to work, cleaned to be sure no debris blocking.

TCM checked, no trouble codes. The resistor/capacitor burn problem does not exist, although about 5 years ago, the TCM had the blown cap/resistor problem, that I successfully fixed, thanks to your forum.

Throttle position sensor checked, proper setting and operation, too.

NO D4 light flashing, no check engine light.

NOW, the car will, IF COLD, start and run and all the gears change properly at the correct points, on road and in stop and go traffic. Normal. No more slippage.

Once the car has run about 10 minutes, and warms up, the darn thing starts shifting erratically, finally going into 1st or 2nd gear and no longer changing. You have to drive it home at 20-30MPH to keep from over-revving the engine.

Sometimes manually shifting will get it to go to D3, but no higher.

If the car sits ind cools down, I can go drive it another 10-15 minutes normally, then the shift problems start back up.

My daughter really needs this car to go back and forth to school. It's been a great vehicle - three kids have used it, 250,000 miles, NO major problems at all until now. can anyone point me in the right direction?

 

torque converter? i know that the tcm in my 90 went bad even though there were no trouble codes. there are places that will rebuild them for like 100 bucks

 

I'm not sure what the symptoms of a bad torque converter are. Guess I'll do a little more research. Even though I rebuilt the TCM myself (electronics background) about 5 years back, I guess it could be intermittent failure, although the car drives great when cold, just starts this crap when the engine warms up.

 

ya that is a puzzling issue

 

My last auto tranny did the exact same thing. It was the tranny itself that was bad and I had to replace it ( I Ended up doing the Auto-5 speed swap)

 

 

Have the same problem...
I have gone from the symptoms Old Geezer describes to new ones after changing both NM and NC sensors, both set of solenoid valves from a used parts yard. Tested and within specs. Now it will shift with a rumble to second and as soon as it warms up it starts to slip on 3rd. It feels like it is skipping teeth on a gear. That's the feeling. If changed manually it will make it to 4th but need to ease the throttle to get there and baby it. There were no codes this time, after resetting a code 15 and changing the sensors. I get a D4 light on when I switch the ignition and the check engine light go out together!
This is insane!!!
Yesterday I rechecked the sensors and solenoids and after a drive got the code 15 back!!!
I will not downshift once in 4th, to pass another car. it will just rev. If you let your foot off the gas coming to a stop light it will downshift through the gears!!!
Checked the trans fluid yesterday (Honda ATF) and it was a little dark even though it was changed a month ago. The magnetized plug had fine, minuscule metal particles but nothing shinny or even larger than a thousand of an inch.
The TCU has been checked for any abnormalities or burnt components. The board looks perfect. No signs of overheated components or bad soldering points.
I have checked the TPS and found it to be out of specs per other postings of 1k OHMS at rest and up to 6500 OHMS at full throttle. That could be next but it is set with break off head screws so needs to be drilled out.
It is driving me crazy to the point I am thinking of replacing the trans all together.

 

This only happens when it gets to operating temperature. Works fine when it's cold.

 

i have some what of the same problem, when i got the car, it would only stay in 3rd, so first off i thought, shift soloinoids, so i replaced them, nothing, then i replaced the tcu, got it to shift properlly, until warm i have the same prob, but it only happens some times, and with the new tcu, it pops the speed sensor code, i replaced that and still nothing, i only have the prob sometimes, so i'm getting tired of swapping parts and stuff, so i'm jus going to do the 5 speed swap and get it all done and over with, with no more prob, but for yours it sounds like the clutchs inside the tranny are going bad, and when they heat up the warp enough to not make contact, i had that prob once with a turbo 350 trans i had in a 66 belair, you can rebuild it (very costly) or you can get a new trans which is the easist way to go, also when you put the new trans in, make sure to do a fluid and filter change, along with a NEW torque converter, if you do all the work and keep the old converter you did all the work for nothing....

 

When the transmission in the '95EX went out it would do a really bad downshift flareup.
If it was cold it was fine, select any gear other than D4 and she would slip badly. Ended up just replacing the transmission with an import unit. Been meaning to tear open the old one and see what was going on.

 

I have same problem,started as it would slip out of gear (nothing,not 1-4) auto trans.If I turned the car off and back on problem solved,move along like normal.I swapped out the tcu,still the same,no codes at all.Now it will slip at the start, you have to start it and let it catch and move on it will only go about 2 blocks and nothing,(D or R).could it just be a bad trans or torque converter.the car has 200,000 miles.