After recent unrelated repairs, auto transmission won't up-shift (sometimes)

[ClareQuilty]

As some may have read, my '93 Honda Civic was recently in the shop for new CV joints and a thermostat (it previously had no thermostat).

Since that repair, those items are functioning properly, but a new problem has cropped up - the auto transmission will occasionally be 'stuck' in low gear. After stopping and shifting into neutral or park this problem usually goes away, only to return later on, usually the next time the car is used rather than on the same journey.

This problem never manifested before the above mentioned repairs, so the timing is very suspicious.. could the mechanic have knocked out some sensor or wire or other electronic gadget that controls shifting?

[seedy]

Two troll / flaming post removed.

Helpful posts welcome.

[cumgranosalum]

You need to give the workshop a chance to put it right.........

I would go back to the place and - tread lightly here - explain the problem....in a away that gently implies you think they may/possibly/just might have caused it. Do this in a very oblique way...this will give them the chance to look at it and - if it WAS them, they should be able to fix it easily and they can claim to have found the fault and fixed it and no-one loses face.

However it is also likely that the 2 faults are quite unrelated in which case is the workshop you use any good with automatics?

I'm not, it is a perpetual area of mystery to me.

Edited November 2, 2015 by cumgranosalum

[cumgranosalum]

Of course if someone posts who has a concrete solution it would help.

Getting what you want from a work shop is 40% knowing what the problem is and 60% handling the workshop in the right way.

Edited November 2, 2015 by cumgranosalum

[seedy]

Another Troll / Flaming post removed.

If you have something to post which will help the OP, by all means feel free to assist him.

Continue to post nonsense and enjoy a posting holiday.

Whether you agree with his choice of vehicles or not is moot - it is HIS choice to make.

[KhunBENQ]

'93 Honda Civic

Maybe its related to the recent repair but maybe just by chance.

Its 15 years old:

Do you know when (how often / last time) the ATF (automatic transmission fluid) has been renewed?

There is also something like "flushing" the automatic transmission box (where my expertise ends).

The repair shop should have expertise with automatic transmissions.

The ATF fluid has to match the specifications of the manufacturer exactly.

Doing both of the above should not cost a fortune and worth a try.

Edited November 2, 2015 by KhunBENQ

[ClareQuilty]

Thanks for helpful comments guys. The car is now in the shop for transmission fluid flush, etc, plus checking the electronic part that orders it to shift. I did mention to this shop my theory that the previous shop may have messed it up somehow, such as a fuse, electrical connection, or sensor.

[WarpSpeed]

Also possibly needs a new screen filter, if it gets too clogged it may not allow enough fluid to travel through and that prevents up shifting due to low pressure sensing. I'd begin with that, if it is any of those things unlikely the previous shop had anything to do with the new problem, but also the axles do attach to the transaxle so anything is possible while they were working, though I'm not privy to what they could have damaged while doing that job on a Honda autobox of that age.

Actually it just came to me that I recently had an older Prelude and it had an external shifting solenoid on the front of the transaxle that was throwing a CEL and 1st to 2nd shift was iffy at best. It turned out that one side of it wasn't working properly and that was the lower gears, the other side was the upper gears obviously the lower gears are used more in most shifting, but anyway that is a very good possibility and easy to diagnose and cheap to repair if able to locate a new one, but I doubt if they damaged it doing the CV's as they are no where near each other, though I guess at some point it's possible they may have unknowingly knocked or damaged a plug loose or something since the plugs get really brittle on cars that age.

Edited November 2, 2015 by WarpSpeed

[ClareQuilty]

Also possibly needs a new screen filter, if it gets too clogged it may not allow enough fluid to travel through and that prevents up shifting due to low pressure sensing. I'd begin with that, if it is any of those things unlikely the previous shop had anything to do with the new problem, but also the axles do attach to the transaxle so anything is possible while they were working, though I'm not privy to what they could have damaged while doing that job on a Honda autobox of that age.

Actually it just came to me that I recently had an older Prelude and it had an external shifting solenoid on the front of the transaxle that was throwing a CEL and 1st to 2nd shift was iffy at best. It turned out that one side of it wasn't working properly and that was the lower gears, the other side was the upper gears obviously the lower gears are used more in most shifting, but anyway that is a very good possibility and easy to diagnose and cheap to repair if able to locate a new one, but I doubt if they damaged it doing the CV's as they are no where near each other, though I guess at some point it's possible they may have unknowingly knocked or damaged a plug loose or something since the plugs get really brittle on cars that age.

Well I do believe he replaced the filter as well, along with the fluid today. The total cost was 900 baht. The car has been shifting properly since, but since it was an intermittent problem, we'll have to wait and see.

I still fear some recurrence, as it was just too suspicious that the problem would crop up immediately after the other shop was messing about with the CV joints, etc. We'll see. In any case I have a good deal of confidence its not 'worn out', as the transmission had always shifted crisply and precisely before this popped up.

[lostinisaan]

Also possibly needs a new screen filter, if it gets too clogged it may not allow enough fluid to travel through and that prevents up shifting due to low pressure sensing. I'd begin with that, if it is any of those things unlikely the previous shop had anything to do with the new problem, but also the axles do attach to the transaxle so anything is possible while they were working, though I'm not privy to what they could have damaged while doing that job on a Honda autobox of that age.

Actually it just came to me that I recently had an older Prelude and it had an external shifting solenoid on the front of the transaxle that was throwing a CEL and 1st to 2nd shift was iffy at best. It turned out that one side of it wasn't working properly and that was the lower gears, the other side was the upper gears obviously the lower gears are used more in most shifting, but anyway that is a very good possibility and easy to diagnose and cheap to repair if able to locate a new one, but I doubt if they damaged it doing the CV's as they are no where near each other, though I guess at some point it's possible they may have unknowingly knocked or damaged a plug loose or something since the plugs get really brittle on cars that age.

Well I do believe he replaced the filter as well, along with the fluid today. The total cost was 900 baht. The car has been shifting properly since, but since it was an intermittent problem, we'll have to wait and see.

I still fear some recurrence, as it was just too suspicious that the problem would crop up immediately after the other shop was messing about with the CV joints, etc. We'll see. In any case I have a good deal of confidence its not 'worn out', as the transmission had always shifted crisply and precisely before this popped up.

Hi . Asking y wife, I thik I know what happened. You forgot the little Tambon in form of a 20 baht bill to the mechanic.

Solution: See the mechanic, give him a sweet smile and Sao baht, tell him to check the transmission box, or go to a monk and organize a hugeTamboon for your car, you know the Thai cultural ceremony where the monk helps you that you won't have an accident, etc..

If a monk didn't see the car, the problems will never end. Best of luck !!

Edited November 2, 2015 by lostinisaan

[pgrahmm]

If the battery had been disconnected the trans had to go through adaptive strategy and relearn.....Usually takes about 70k to do that and it can select wrong at times but then will be OK.....Yours almost sounds like it was a low fluid condition and don't know why but they might have removed or broken a cooler line and not topped the level → but that should be solved now with the flush and fill....

One of our cars recently had a sporadic trans problem → turned out to be the battery.....Voltage dropped over night and controller lost memory then every morning it was relearning - but after parking for shopping or short time was OK & OK during the day.....Thought the trans might be failing but battery was kaput → slower cranking (diesel - easier to tell).....Replaced the battery and everything has been fine ever since → about a year.....

[ClareQuilty]

Oh I have a theory - maybe the problem isn't the transmission, but rather the automatic choke, (which doesn't work). So, with no high idle during warm-up, the transmission controller is all confused. The renter says the problem 90% goes away once the car's just a bit warmed up.

[Ace of Pop]

Im not interested much anymore with probs but a Chum who knows Hondas quite well tells me the Exhaust Gas annalist thingy if not perfect can cause strange things to happen.. Warpy can add to this comment better than most. Nice to know what gremlins it may cause..

[pgrahmm]

Reading a colder engine should only delay upshifts during warm up/closed loop operation to raise the temp quicker for emissions purposes....Working properly it would hold the shift points higher until the correct engine temp is obtained.....

Since it was OK without the Tstat before seemingly this wouldn't be cause and effect now....

[ClareQuilty]

Just did a little research online, which suggested that this problem is a common one with this generation of Honda Civics, and that it is typically the "TCU" or Transmission Control Unit. Anyway, the car's headed back to the shop tomorrow, we'll see if they can fix it.

[pgrahmm]

Thanks for the update......

Many have/report concerns (wanted to say issues - but this Is TVF)....

But only a few follow up - thanks for being one of them.....

[overherebc]

A late add on.

Most , not all autos the level should checked while the engine is running. Checking with engine not running gives a different level reading.

Check the manual for your model.

[pgrahmm]

A late add on.

Most , not all autos the level should checked while the engine is running. Checking with engine not running gives a different level reading.

Check the manual for your model.

And at operating temperature....Important - and some may also ask to cycle the gear selector first in and out of gear....

[lostinisaan]

A late add on.

Most , not all autos the level should checked while the engine is running. Checking with engine not running gives a different level reading.

Check the manual for your model.

And at operating temperature....Important - and some may also ask to cycle the gear selector first in and out of gear....

Most boxes I dealt with, engine hot, foot on the brake,run it through the gears manually, leave engine running, put in park, pull the stick, wipe it, put it back and pull it out straight away and look at the level on the stick.

There ae still mechanics out there who check the auto trans oil without the engine idling.

And not too many of them know how to use a voltmeter. Only the older and more experienced mechanics seem to be a little better.

Sad is that cars get fixed, but not the problem why something stopped working. Welcome to the 21st century.

Just wondering how they fix a new Porsche or Benz if the don't even know simple electric/electronic troubleshooting at a 17-year-old Mitsubishi.......

P.S. Here's how to flush the system, the OP might want to give it a try....https://www.youtube.com/watch?v=nZAmcEf9LrY

Edited November 14, 2015 by lostinisaan

[pgrahmm]

A late add on.

Most , not all autos the level should checked while the engine is running. Checking with engine not running gives a different level reading.

Check the manual for your model.

And at operating temperature....Important - and some may also ask to cycle the gear selector first in and out of gear....

Most boxes I dealt with, engine hot, foot on the brake,run it through the gears manually, leave engine running, put in park, pull the stick, wipe it, put it back and pull it out straight away and look at the level on the stick.

Level surface....