Transmission Trouble

Just changed my trans fluid. I had heard from my buddy that I should change my diff fluids, trans fluid, and transfer case fluid. Now I'm getting P0741-Torque Converter Clutch Solenoid Performance Stuck off from the ECU. In need of help, any input would be greatly appreciated!

 

Can you explain how you serviced the transmission in detail ?
Here is a write up I put together . I think there is enough information within the lower part of the thread to help you with your converter code
https://www.tacomaworld.com/threads...sions-write-up-your-4-speed-automatic.325531/

 

I went down to O'reilly's picked up 2 quarters of toyota's transmission fluid, drained the old fluid and replaced with the new, found it was a bit low, came on to tacoma world and read that there was supposed to be double that amount? went back down to O'reilly's in a different car, and then put what I think would be the correct amount in based of of what I read, drove over 500 miles and then the code popped up

 

Judging by your explanation of the transmission service , I am going to go with the solenoid being all plugged up with debris .
The engine has to be running to check the transmission fluid . I am sure you know this now .
Here is a technical service bulletin to help
diagnostic trouble code p0770 M.I.L._ON_DTC_P0770_T-EG025-02.pdf

 

What is two quarters? 50¢ doesn't buy a lot of fluid.

 

The TSB I posted in the above thread is only to assist you with diagnostics .
Whats happening ? The computer in your truck is commanding the electrical converter clutch solenoid to energize .
When the solenoid energizes , the torque converter clutch comes on to save you fuel .
The computer in your truck is sending a command to energize the solenoid , but the solenoid isnt answering back , therefore , your converter clutch will not come on and you waste fuel .
How to fix it ?
Take the transmission pan off and clean or replace the solenoid .
Do you have a digital volt ohm meter ?

 

Meant to say "two quarts"

 

Do you have a V6 or V4?
How much fluid did you drain out?
What exactly Brand ant type of fluid You bought?
How many miles in your truck?
You have 2 dipsticks, one for the transmission fluid and the other one for the engine oil. Are you sure you didn't use the engine one to put transmission fluid in?

 

I have the 3.4 v6, I used the trans dip stick I'm sure, and I bought the Valvoline Import multi-vehicle full synthetic auto trans fluid for toyota, honda, nissan, hyundai/kia (bought at O'reilly's)

 

Yes I have a volt meter, and you were right about my gas mileage going down

 

What are the chances you accidentally moved the wiring on the side of the transmission when you changed the fluid ?
With the transmission pan removed , test the resistance of the solenoid .

Before going further or ordering parts , you should identify your transmission as there are many variations of the 340 series
Identify your truck Type in your make and model number here to identify your transmission
https://www.atsg.us/atsg/transtype

A great write up with pictures removing a 340 series 4x4 transmission for faulty torque converter with PO770 https://www.yotatech.com/f2/tranny-issues-p0770-s-o-s-294937/

And here
https://www.tacomaworld.com/threads/sonnax-zip-kit-a340-late-installation.435019/#post-14714790

 

My truck has he A340f trans, where would I order parts for this trans?

 

You can get parts through any local transmission shop or Toyota dealership .
You can purchase cheaper sometimes through ebay but quality control is a little sketchy on crappy electronics

 

Ended up getting it rebuilt at place rated 5 on yelp. They ended up rebuilding it twice because it came back again after the first time. I just got the truck back earlier today after the 2nd trans rebuild and drove about 90 mile when I started to noticed it wasn't going into lockup before. The A/T oil temp light eventually came on, pulled over checked the fluid, seemed good (red and not too hot). Drove on it not even 50 feet then P0741 showed up yet again. Anything those guys could be missing when they rebuilt it? It was working perfect when for those first 80ish miles

 

Sounds like they forgot to plug in the wiring for the transmission temp sensor or possibly broken wiring now .
Bring it back to them and make them fix it correctly .
I would start by diagnosing your PO741 code .
If the transmission temp sensor is disconnected or faulty , you get no converter clutch application

 

Hopefully they'll make it right for you.

What do you mean 'rebuilt'. The whole trans out and done? Or just the pan drop and what's accessible that way?

As a sidebar, I never use Yelp or any of it's cousins for things that are complex. You don't know the reviewers, therefore you don't know the accuracy of the review.

 

It is normal for trans temp to overheat if converter does not lock up. I wonder if the overhaul included a rebuilt torque converter, I am not saying the converter is bad but if all else checks out and they reused old one it could be the problem. When the computer commands lock up it then looks at engine rpm and vehicle speed and if it doesn't see rpm drop light comes on

 

I had a code P0770 and the TC fixed it. The symptoms for your 741 match mine to the T.
https://www.yourmechanic.com/articl...uit-performance-or-stuck-off-by-jamahl-walker

What about the ECT sensor?

Read the process I went thru here....
https://www.yotatech.com/f2/tranny-issues-p0770-s-o-s-294937/

 

Before Taking the Truck to the shop

Changed the transmission fluid near 85000 miles and then drove to Tahoe from santa cruz mnts. ECU gives off P0741 and I find out that it’s Possible that I have too much fluid in the trans. Take some out and try to get it as close to the proper amount. I drive back to San Luis Obispo with the code still on. By the time I get to the top of the cuesta grade the A/T oil temp light came on, I then coast down in neutral so cool down the trans, I get back to the dorm I was living in at the time and check the fluid. The fluid had a color/consistency of gear oil and had an awful smell to it, the fluid also had metal flakes in it.

Taking it to the All automatic:

Decided to go with all automatic because the shop I was going to take it to would just take it to All automatic. At this point I have closer to or more than 86000 miles on the truck. Decided to get a rebuild done, a week later they have me pick it up. I knew it wasn’t right the moment I turned on the truck, there was a new sound that wasn’t supposed to be there. They told me to drive on it later that day the code came back. I was on the phone with Rob (the owner) the next week and his initial idea was to replace the whole transmission (A340f for the reader’s knowledge). I take it in later that week and they said they found the problem, their torque convertor supplier has been messing up lately so they replaced it. Later that day P0741 comes back, the truck would sometimes go into lock up and others times wouldn’t. I take it back in again and they said that the torque convertor was slipping just enough to have the ECU sendoff P0741. I get truck back again on a Thursday (I think, could’ve been Tuesday), Mother’s Day weekend is coming up and the truck was working fine up until Saturday. I fill up at conserve fuel on Santa Rosa, I’m leaving the station and I thought that the trans slipped as I was pulling out but I thought I was just imagining it. For reader discretion, I was driving 65/70 mph on 101. get half way to Santa Cruz (about King City) and that’s when the trans started slipping a lot and wouldn’t shift all the way up, I pull off the high way call my dad, he tells me I might as well go the rest of the way and I do. As I drove back to Santa Cruz (55mph the rest of the way) to help prevent it from braking further. When going 55MPH the motor would be at about 2400 rpm, usually the motor should be sub 2000 or even sub 1900 rpm at 55mph. Also, when I would let off the gas and the original broken solenoid would engage so I knew this was a different problem, but while this solenoid was engaged I noticed a hissing/scraping sound, possibly metal on metal or fluid or something else I have no idea. My Thoughts were confirmed when I arrived at my parent’s house and scanned code to a P0756 which is solenoid B. I drove it back to SLO 55mph the whole way and dropped it off at all automatic for the 4th time. They decided to replace it with a freshly refurbished A340F transmission.

 

Really curious to what happened that trans, they do think the previous owner had something done. They did say say that they have been going through some trouble with their torque converter supplier and have had some similar problems with other Tacomas but mine was definitely the worse. Any ideas to what happened would be appreciated if shared. Makes me wish i bought the manual.