Shifting / Transmission Issue

I have a 2011 Taco with the following shifting/transmission problems. Note that these symptoms do not occur every time I operate the vehicle. It's sporadic. Most of the time it drives like a dream.

1. When driving, sometimes the transmission gets stuck in a gear (seems it's usually 3rd or 4th gear). This can be corrected while driving by shifting into N, turning off the ignition, starting the vehicle, shifting into D. That fix works 100% of the time and causes the vehicle to seamlessly shift into all gears and operate flawlessly.
2. From a dead stop, if I apply the gas at a moderate to aggressive rate, the motor revs for a second then drops into gear
3. When driving and I need to accelerate, the transmission will downshift then get stuck in the gear it downshifts to.
4. Whenever I apply minimal and/or normal throttle, the engine and transmission function perfectly. Smooth shifting, with seamless and effortless transition through all of the gears.

The shifting problem seems related to the amount of throttle I apply at any given time. I drive like an old lady so most of the time I have no issues.

That said, Toyota diagnosed it as an unspecified "electrical issue" that can only be corrected with a new transmission for a total cost of $4,500. That seems absurd so I picked up the vehicle (much to their dismay and surprise).

Any thoughts?

Thanks,

Brian

 

Take it to a transmission shop and get a second opinion.

 

@gearcruncher

 

Its a completely computer controlled transmission and judging by your diagnosis , the transmission is storing a soft code .
When this happens , the computer in your truck sees a problem and prevents the transmission from shifting into certain gears . It will shift hard and skip gears until you fix the code .
When you cycle the igntion key , the code goes away and the truck operates as it should
Have you scanned for codes ? Do you have a good quality scanner ?
I would never ever use the dealership for diagnosing transmission issues .
That was an incredibly horrible diagnosis from your dealership .
Whats your mileage ? Need your mileage and transmission service history ?
Is your transmission topped up with fluid ?

If your truck was in my shop ?

Scan for codes during a test drive and proceed from there


Some reading when you get a chance https://www.tacomaworld.com/threads...th-pics-for-second-gen-4-liter-trucks.289913/

 

Sorry, don't mean to steal this thread, this question is for gearcruncher, I am getting torque converter shudder, flushed all atf via taking 3 quarts out of pan, refilling, then, disconnecting cooler line in front, then starting truck, to pump out 2 quarts, refill, repeat, until all atf was changed. I was told by a auto mechanic that I was just flushing the new fluid out of the pan, is this correct? The shudder did not get better and I added lube guard, truck has 120k miles, last dealer trans service was at 92k miles, thanks.

 

If you were flushing transmission fluid out the cooling line at the front of the truck , the fluid travelled through the transmission and torque converter and then into the cooling lines .With this being said , you performed the flush correctly .

Have you performed a " brake tap test "
When was the last time your engine was tuned up ?

https://www.tacomaworld.com/threads...th-pics-for-second-gen-4-liter-trucks.289913/

 

I replaced the plugs about 5k miles ago, tried the tap test didnt really notice any change, ill have to try again, thanks!

 

Thanks for the information and suggestions. The truck has 135,000 on it and has never had any transmission service that I'm aware of (purchased with 70K). I have not scanned for codes, as I figured that's what Toyota would do. So I'll start with that and then take it to a transmission shop if no codes are thrown that I can't fix myself. Thanks, again.

 

So I ran a ODB scan on it and the truck tripped a P0776 Transmission Pressure Control Solenoid code. I have continued to drive the truck and it only seems to struggle under hard acceleration. If I drive it moderately to gently, it shifts as normal. What's my next step? Tranny shop to have that solenoid replaced? I'm fairly mechanically inclined but is this job more than most can handle?

 

Its easy enough. I did this one (SLT solenoid) on mine. Drain the pan, drop the pan (good time to clean magnets and change filter and gasket), locate solenoid, unplug, unscrew retaining bolt (careful, a pin might drop out when the bracket is removed. be sure to replace before closing it back up), slide out solenoid, slide in new one, reverse the rest of the step, bobs yer uncle.

 

can @gearcruncher confirm that code relates to the SLT solenoid?

 

Thank you. This is the report that the OBD scanner provided:



=================================================
Vehicle VIN:
Vehicle Manufacturer:
Vehicle Calibration ID:
Current Fault Log
------------------
P0776: Pressure Control Solenoid "B" Performance or Stuck Off
Pending Fault Log
------------------
ECU reports no pending faults
Historic Fault Log
------------------
ECU reports no historic faults
Other discovered fault codes
(possibly pending, current or manufacturer specific)
----------------------------------------------------
ECU reports no other fault codes logged
End of report.

 

Just beware that if a code points to a certain part like in your case a Pressure Control Solenoid. Replacing it doesn’t necessarily mean that it will fix your problem. That’s where a skilled transmission guy will zero in on the real culprit. It could be a number of things, lose connections, low fluid ect. Depending on how many times you want to remove your tranny pan and fluid, this could be an expensive trouble shooting experience.

 

Low fluid I can check myself, right? Just by checking the operating temp of the fluid? I supposed I could do that at home, yes?

 

Yes, That’s should be the first thing to check is your fluid level. You will need to put it in temp check mode.
There is a how to do write up in the 2nd gen maintenance area.


https://www.tacomaworld.com/threads/how-to-drain-refill-automatic-transmission.63851/

 

I have a 2020 OR with 40,000 miles. It is similar problem. Never locks but same code came up. Took it to the dealer and was told the same thing other then mine would cost $5100 I definitely went a picked it up paid them there $150 for wasting my time and took it to a transmission shop. Still waiting on what he has to say. Hopefully tomorrow. Did you ever get your problem resolved? If please share.

 

Why wasn’t it covered under the warranty?


Powertrain Coverage1 60 months/60,000 miles (engine, transmission/transaxle, front-wheel-drive system, rear-wheel drive, seatbelts and airbags).

 

Oh, wow. I hate hearing that, bro. No, I haven't had time to take it into a tranny shop yet. Like I said, as long as I don't go above 60% throttle or decelerate aggressively, my truck runs really quite well. Good luck, man! Let me know what the outcome is, as it may be related to my issues.

 

So we just got it back from the transmission shop. It was just under 1 gal low on oil. Freaking crazy because the dealership said oil level was fine. Is of right now it drives fine. We won’t know how bad if any damage has been done... well until it dies. But they did give me. Verbal quote of around $2000 for a rebuild and a new factor valve body.

 

So interestingly enough, the Transmission Pan reading only got to 110 deg. F after idling for 15 minutes. If my research is correct, this is abnormally low? Wouldn't this be indicative of too MUCH fluid (which couldn't possible be)?

This is the PID I'm using on my 2011.

PID: 2182
Unit: Fahrenheit
Max: 300
Min: 0
Scale: x1
Unit Type: °F
Equation: ((((A*256)+B*(7/100)-400)/10)
Header: Blank