Where did the Trans Fluid change technique come from ?

The way I read about our new Tacomas is that their transmissions have "lifetime" fluid and never has to be changed. IF this is true , then where did the technique about how to change our trasnmission fluid come from ? I'm talking about where you have to ground the 2 terminals oto get the truck into "check" mode and then letting the fluid drip out the check plug and so on. Was it a TSB from the factory ? I'm getting very near to changing my fluid out and I'm just curious on how this style of "sealed" transmission fluid change came about. Dont get me wrong , on all my vehicles , I change the trans fluid every year whether it needs it or not. That's how I have 300,000 miles on my Honda and 320,000 on my 23 year old Mazda. Any help or information is appreciated.

 

I've never heard of the lifetime transmission fluid

 

It has always been replaceable, they're just saying that the average driver does not need to replace it.
By the way, on newer models you do not need to jump the wires. Mines a 2020. Hold brake. Shift p to s to p. Then the n-d back and forth. Same process, but no wire needed.

 

The procedure for overflow and OBD pin jumping for trans level check mode is from Toyota service documents.

The 2020+ use a shift lever sequence, otherwise the same process.

 

I believe it's like a bow warranty where they say it's warrantied for life. They don't stock parts for it after five years so that's the life of it( Mathews is the exception). So with the tranny fluid its life time meaning until the warranty expires,after that they don't care. The fluid will last longer and people put lots of miles on original fluid but it's not optimal. Just a theory.

 

It's not unique to Toyotas, or even a new practice. My first car (a 1997 Isuzu) didn't have a transmission dipstick.

Mechanic back then told me manufacturers removed the owner's ability to service the transmission, because people kept screwing it up. More fluid is generally worse than low fluid, and it's too easy to misread the dipstick. (Picture with the size of the pan, 1/4" on the dipstick could be 1/2 quart or more of fluid).

Comparatively, engine oil has a lot more tolerance for wrong levels than the trans, so the simple dipstick remains okay.

You could also make the argument that the diffs and transfer case are just as sealed as the trans; they are just easier to fill when you service (fewer side streams for the fluid).

 

The method is in the factory service manual. Been there for at least two decades since the A750 trans came out with the 2003 4Runner. The design decision was based on the social-economic conditions at the time.

 

you don't have to use the jumper method on the newer trucks. you can enter temp check mode just by shifting in the right sequence.

 

Mine is a 2022 2.7 liter that is 2WD. My older Taco was a 2003 2.7 in 4WD. I loved that transmission. 4 speed and a dipstick. I changed the fluid every year and even disconnected the transmission cooling lines from the radiator and let the transmission run through a seperate transmission cooler. It ran cooler better than way and kept any "strawberry milkshakes" from happening.

 

how long will this keep the transmission in "check mode" to let you run the excess fluid out ?

 

Until the temperature gets too high

 

There's no such thing as lifetime tranny fluid and anyone who tells you that is smokin' something strong. That is unless these trucks are only made to go to 100k.
For reference, around 70k I developed a vibration in second gear when my rpms were under 1,500. The culprit? Transmission fluid. Changed it and haven't had an issue since and am now at 85k. It's now in my every 60k maintenance rotation with spark plugs and such.

 

it is true that Toyota was calling it a lifetime fluid, they did the same on the Lexus LS. They only did this in North America and it is total BS marketing. Aisin recommends a drain and refill every 30k. No need to drop the pan unless a repair is needed.

 

have any of you guys did the fluid change with the newer style transmission by just shifting instead of using the wire method ?

 

Can we please stop referring to the transmission as “sealed”? It has three different plugs. It’s not sealed. Maintenance capability was designed in.

 

When you cycle the ignition power it resets the "check mode". Otherwise it will stay in check mode until you're done.

Yes. Just did mine recently. Worked fine.

 

I own a 2013 SR5 4x4 Base. 107K on the clock. This is the only service I have done at the dealer. Smells like epoxy glue for a couple of weeks after. Change at 75K miles.
Service Department told me "Sir we do not recommend service intervals until 100K" I said that's fine can you change my fluid anyway. Sure they said.
Wife's old 2005 Corolla had 250K on it. Transmission Fluid Changed 3 Times. Running like a clock till I wrecked it.

Her 2015 Corolla done at 75K now has 137K about to do it again. Sticking with 75K Intervals.

 

You may find this video helpful.

https://www.youtube.com/watch?v=rNqYpEpmUng

 

It’s based on fluid temperature and fluid expansion.
Just shifting will not work.

The procedure came from the factory service manual.

The jumper method is for techs (or regular DIYers) that don’t have a scan tool capable of reading trans temps.

When in doubt, measure what came out.
Add back what you measured.

 

He was referring to using the shift sequence to put it in "temp check mode". It works on 2020+. No wire jumper required.