smabuki

Hi guys

I'm pretty frustrated. I bought a Honda Accord 91 and was having problems with the transmission since then. First I got the S4 light and the car wouldn't shift out of the first gear. So I changed the speed sensor and after that it worked fine for 800miles, allthough it shifted hard. But I heard this is normal with these cars.

One week ago it started having problems shifting into the second gear. It felt like it has not the power to shift and then it would just slip. That didn't happen all the time. Driving on the freeway was also fine (once the car was in gear 3/4). Today I changed the transmission solenoids hoping that would fix it. After that change it is stuck in the second gear. That means it starts driving in the second gear and doesn't shift up.

Has someone an idea what the problem might be? I lost some transmission fluid, but when I look at the level it seems fine. I checked it with a warm motor.

Would be very grateful for help.

Thanks
Alex

MAD_MIKE

What code was stored in the TCU?
You did retrieve the code from the blinking D4 light via jumping the diagnostic connector, right?

smabuki

The code back then was the speed sensor. The warning light went away after replacing it.

MAD_MIKE

90-91 Accord TCUs were built with a few inferior capacitors and resistors...
http://techauto.awardspace.com/transmission.html

Check to see if those components are damaged, if so a couple of bucks in caps/resistors and some soldering should fix the problem.

Also recheck that the connections at the shift solenoids are clean and tight, you may want to swap the old sensors back and see if antying changes.

smabuki

Thanks a ton Mike.

The weird thing is that it shifted before I replaced the solenoids. I tested the old shift control solenoid and one of them is clicking not as loud as the other does.

Is it possible that this is due to low transmission fluid? I lost quite a bit (see picture). The weird thing though is that if I control the fluid it seems that it is even too much.



https://www.dropbox.com/s/wtryjq8zspaf8xd/photo-5.JPG

smabuki

Oh and I also opened the TCU and it loos actually fine.

Grandhustleman86

When you opened the TCU did you see any corrosion (whiteish dust) did you really get a good look top and bottom of the board? They are very susceptible to the solder corroding on various resistors/wires ect. I would get that trans full of fluid then after checking/cleaning connections to the solenoids try again...if still no glory swap back to the old solenoids...if still no glory pickup a used TCU (verify which number your TCU has on it 28100-PX4-832 - 28100-PXO-833 bc these are not interchangeable) from a salvage yard and swap it out with both methods (new-old solenoids). this should resolve your issue.

smabuki

Yeah, I had a close look. Nothing is burned.

I also put in the old solenoids and it's the same. Still stuck in the second gear.
When I put in the new solenoids again I tore of the bolt but got it out.

Btw. the second gear is the one I was in yesterday when it started slipping and I just turned off the car. Is it possible that this due low transmission fluid or is it maybe internal damage? When I put in R the car jerks, the same when I put in D4.

MAD_MIKE

If the transmission fluid is low you will have a delayed or missed shift. When the fluid is low the transmission will grind the syncros. Honda ATs are more in common with MTs than any other AT.
Warm up the engine, park the car on a level ground, charge each circuit for about 5 seconds. P>R>N>D4>D3>D2>D1. Place back into PARK. Pull dipstick, wipe clean, reinsert, pull out. It should be within the hash mark area.

smabuki

Changed the fluid and it was rather too much. So thats's good. Still stuck in second gear though. I read something about the limp home mode which sounds like my problem. Trying swapping the TCU next, hope that fixes it.

Is it possible that the transmission has a mechanical problem when it goes into limp mode? Anyways, that's my last try. If this doesn't help I give up

smabuki

So weird. I found the issue. Replaced the Solenoids with used ones and the seller seemed to have switched the cables in the pin.

Thanks a ton for your help guys.