transmission not shifting correctly?

The is a fault in the transmission control system and a diagnostic scan might tell you what control fault is causing this. It could be the speed sensor or throttle position sensor. THis gudie can help as well

https://www.2carpros.com/articles/automatic-transmission-problems

Please run down this guide and report back.

there are three speed sensor which one can it be?
i do not have a check engine light on.

One is the vehicle speed sensor and the other two are input and out shaft sensors. Any one of them can be the culprit but each sensor fault would be specific to their problem. Some trouble codes do not trigger the Check Engine Light and only going into diagnostic mode would you be able to now if anything is wrong.
Sometimes a fault with the throttle position sensor is not captured by the ECM and only looking at live data would you be able to understand if it is working correctly.

ok i change the tps and both speed sensors problem still exist would the gear selector switch cause this

ok here the latest update i am getting a code 9 which say speed sensor the countersahft sensor i replace the shaft and the sensor but what happens is that when taking of the car shift ti 2nd gear and when time to shift to 3rd it downshift to a lower gear instead what else can i check

it refuse to go into 3rd gear

Sorry for the delay in getting back to you.

This is the rectification procedure from the shop manual. Go through it and see if there is anything you have missed out.

DTC P0720/9: COUNTERSHAFT SPEED SENSOR
Using scan tool, retrieve A/T freeze data. Clear fault codes and road test vehicle under same conditions freeze data was recorded. If fault code returns, go to next step. If fault code does not return, problem is intermittent, check mainshaft speed sensor and PCM connections.

Ensure countershaft speed sensor is installed properly. Disconnect countershaft speed sensor harness connector. Using a DVOM, measure resistance between sensor terminals.

If resistance is not 400-600 ohms, replace countershaft speed sensor. If resistance is 400-600 ohms, disconnect 16-pin PCM harness connector "D". Check for continuity between ground and 16-pin PCM harness connector "D", terminals No. 16 (Green wire) and No. 10 (Blue wire). See Figure .

If continuity is present, repair short to ground in Green wire or Blue wire between PCM and countershaft speed sensor. If continuity is not present, reconnect countershaft speed sensor harness connector. Measure resistance between 16-pin PCM harness connector "D", terminals No. 16 (Green wire) and No. 10 (Blue wire).

If resistance is 400-600 ohms, check for loose PCM harness connectors. Replace PCM with a known-good unit if necessary. If resistance is not 400-600 ohms, repair loose connection or open in Green wire or Blue wire between 16-pin PCM harness connector "D" and countershaft speed sensor harness connector.

well recently what has been happening is that it shift out fine but when going into third it catches then it releases the gear. if i rev up engine it catches again this is back and forth while driving. some times when i pres pedal to the floor it catches again and then same thing over and over.

Based on symptoms it is difficult diagnose the problem and since trouble codes are present, we need to have it diagnosed and rectified. If after the codes are cleared and do not come back and the symptoms are still present,, we would need to test the hydraulic pressures etc.

Okay, i had to rebuild the transmission i notice that the two little filters on the valve body was clogged. also the main filter was clogged. i replace all clutches all filters and dismantle the valve body and rebuild. now car works fines the clutches was not fully gone.

Thanks for assistance.

Glad you could get it fixed, that kind of problem can be tough. Please use 2CarPros anytime we are here to help.

Cheers, Ken

The transmission puts itself in neutral whenever the RPM's get to about 3,000 (when it is supposed to shift to the next gear). My mechanic replaced the fuel filters and the problem went away for about six months but after further research I was able to find that it may be the transmission filter. When it acts up, I have absolutely no power (so basically neutral) and I have to keep the RPM's between 2,500 and 3,500 and it will shift after a little encouragement.

Welcome to 2CarPros.

The first thing that comes to mind is low fluid. Have you checked it? IF it is clean and full, my next suspect is the transmission clutch pressure control solenoid. Here are directions to test it. The attached pictures correlate with these directions.

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A/T CLUTCH PRESSURE CONTROL SOLENOID VALVES A AND B TEST
Test


picture 1


1. Disconnect the A/T clutch pressure control solenoid valves A and B 2P connectors.
2. Measure the resistance of the A/T clutch pressure control solenoid valves A and B between the No. 1 and No. 2 terminals of each connector.
STANDARD: About 5.0 ohms
3. If the resistance of either A/T clutch pressure control solenoid is out of standard, replace the A/T clutch pressure control solenoid valves A and B.
4. Connect the No. 1 terminal of the A/T clutch pressure control solenoid valve A (and B) to the battery positive terminal, and connect the No. 2 terminal to the battery negative terminal. A clicking sound should be heard.
5. If not, remove the A/T clutch pressure control solenoid valves A and B.
6. Check the fluid passage of the A/T clutch pressure control solenoid valves for dust and dirt.


picture 2


7. Connect the No. 1 terminal of the A/T clutch pressure control solenoid valves A and B to the battery positive terminal, and connect the No. 2 terminal to the battery negative terminal. Make sure the A/T clutch pressure control solenoid valves A (A) and B (B) move.
8. Disconnect one of the battery terminals and check valve movement.

NOTE: You can see the valve movement through the fluid passage in the mounting surface of the A/T clutch pressure control solenoid valves A and B body (C).

9. If either valve binds, or moves sluggishly, or if the A/T clutch pressure control solenoid does not operate, replace the A/T clutch pressure control solenoid valves A and B.

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Here are a few links you may find helpful when testing:

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

https://www.2carpros.com/articles/how-to-use-a-voltmeter

https://www.2carpros.com/articles/how-to-check-wiring

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If you find that is the problem, here are the directions for replacement. Picture 3 correlates with these directions.

A/T CLUTCH PRESSURE CONTROL SOLENOID VALVES A AND B TEST
Replacement


picture 3


1. Remove the mounting bolts and the A/T clutch pressure control solenoid valves A and B (A).
2. Clean the mounting surface and fluid passage of the A/T clutch pressure control solenoid valves A and B and the transmission housing.
3. Install a new A/T clutch pressure control solenoid valves A and B with a new gasket (B), new O-rings (C), ATF feed pipes (D), and harness clamp bracket (E).

NOTE: Install the filter side of the ATF feed pipes in the transmission housing.

4. Check the A/T clutch pressure control solenoid valve connectors for rust, dirt, or oil, then connect them securely.

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Also, here are the directions for testing shift solenoids.

See picture 4 and 5

1. Disconnect the shift solenoid valve B or C 2P
2. Measure the resistance between the No. 1 and No. 2 terminals of the shift solenoid valve B or C.
STANDARD: 12 - 25 ohms
3. Replace the shift solenoid valve B or C if the resistance is out of standard.
4. If the resistance is within the standard, connect the No. 2 terminal of the shift solenoid valve B or C connector to the battery positive terminal, and connect the No. 1 terminal to the battery negative terminal. A clicking sound should be heard. Replace the shift solenoid valve B or C if no clicking sound is heard.

________________________________________

Check these things and let me know what you find. Also, let me know if you have questions.

Take care,
Joe

On cold start the transmission will not shift up from 1st gear. As car warms up it will start to shift regularly although with some hesitation. Have done power flush on fluid with same result. Told by mechanic that no servicable filter on this transmission, and shift sensors check out electrically. Any thoughts out there? Daughters car, i great shape except for this problem.

Hi woodsplace,

Symptoms indicates the shift solenoids could be sticking and when this occurs, shifting is affected. They might not throw any codes and as the shift sensors are external, remove them and try cleaning to see if it works. THis gudie can help as well

https://www.2carpros.com/articles/automatic-transmission-problems

Please run down this guide and report back.

Engine Performance problem
1998 Honda Accord 6 cyl Two Wheel Drive Automatic

my car does not changes its gear automatically when accelerating

Hi oy,

Get a scan done to retrieve for trouble codes and let me know what you find.

culdnt get a scan 2 be done,,,,,but my gear indicator ligth is alway binking has i engage on any gear

Autozone and most major parts outlets provides free scanning services.

The D4 indicator light blinking indicates an error has been detected in the transmisison control system.

Without retrievng the trouble code, it is not possible to diagnose the problem.

My friends accord started shifting hard and now doesn't want to shift. The fluid level is good and the fluid doesn't seem to be burnt. I'm a shade tree mechanic and I know some automatics need to be put on a machine and drained so there is no air introduced into the system, is this a fact with the honda? Or, can I change the filter myself like I have done to other models?

Hi rcgygi,

Firstly this transmission is equipped with a maintenance free strainer and there is no filter to be replaced. For replacement you need to strip the transmission.

Secondly for fluids, you top it up and drive, there are no such thing as air in system. The running of the pumps would clear all the air in system, unless it is overfilled when churning occurs and bubbles are introduced into the pump or if the level is too low and air is sucked up by the pump.

Thirdly, when the transmission fails to shift, you need to check the symptoms.
Does it move in reverse?
Any gears that is working?
Have you tried to retrieve for trouble codes?

Recently I changed the ATF of my car and it started thudding and sliping the gears while shifting. These problems were never experienced before in the car. Kindly advise me how to tackle.

Hi Saeed Ahmed,

Is the fluid level correct?

Was the fluid used of the correct specification?

i assume the transmission may be defective but before i replace the transmission maaybe the problem might be electrical ecu/trabnsmission ecu or some other sensor.

the transmission will onlly change into second gear , sometimes to third gear and down shifts quickly at times.

what do you think i should do first to diagnos.

thanks mike

Hi michael 11,

The first thing you need to do is retrieve for trouble codes. Let me know the exact code if any found.

Autozone provides free scanning services.

About a few weeks back I was going up MontEagle Mountain in my car when I noticed that it wouldn't hardly pull itself up the hill. I stopped at a store and turned my car off to let it rest for a second and checked the trans fluid it was fine. When I continued on my trip the car run fine for about another hour, then I noticed that the car started to have problems staying in gear for example I would lose D4 then I would shift into D3 and it worked for a while and then it started doing the same thing in that gear. I stopped again and let it rest for a few more minutes and it run fine again. It kept this pattern for a few days and I finally had someone come scan it they said it showed three different codes P0730, P0740, and P0138 I believe this is right that last one was I know that they said one was the gear ratio anyways they reset the codes and the car run fine for about 10 minutes and then started slipping again. I have not touched it since until today when I decided to drive it and it run fine for about 30 minutes with me having to only turn it off once in that time and then it run fine again. Could it be a lock up shift solenoid? Or if you have any suggestions of what it might be that would be great because I have been told that I need a new transmission but have also been told I do not. Any advice would be great thanks!

[quote:1d875df2a9="accord_boi"]Transmission problem
1998 Honda Accord 4 cyl Front Wheel Drive Automatic 168000 miles
----------------------------------------------------------------
About a few weeks back I was going up MontEagle Mountain in my car when I noticed that it wouldn't hardly pull itself up the hill. I stopped at a store and turned my car off to let it rest for a second and checked the trans fluid it was fine. When I continued on my trip the car run fine for about another hour, then I noticed that the car started to have problems staying in gear for example I would lose D4 then I would shift into D3 and it worked for a while and then it started doing the same thing in that gear. I stopped again and let it rest for a few more minutes and it run fine again. It kept this pattern for a few days and I finally had someone come scan it they said it showed three different codes P0730, P0740, and P0138 I believe this is right that last one was I know that they said one was the gear ratio anyways they reset the codes and the car run fine for about 10 minutes and then started slipping again. I have not touched it since until today when I decided to drive it and it run fine for about 30 minutes with me having to only turn it off once in that time and then it run fine again. Could it be a lock up shift solenoid? Or if you have any suggestions of what it might be that would be great because I have been told that I need a new transmission but have also been told I do not. Any advice would be great thanks![/quote:1d875df2a9]

Same Problem,

My Accord started having a very simialr problem on Friday. Mine is a little less controllable. I've found that if I press the accelerator and rev it up, it will up shift to the proper gear for while before shifting down again. I am taking mine to the shop tomorrow. If I learn anything, I will try to post here. Please post again if you learn anything.

Thanks, Ndmad