Transmission temps while filling transmission

I'm looking to change my transmission fluid and I know the trans fluid temp should be 115-130F. I am trying to figure out if this temp is at the TC or at the pan? I have OBD Fusion app with the paid Toyota/Lexus PIDS. I am able to pull two different trans temps, one I assume is near/at the TC and the other is pan. There is roughly a ten degree difference.

I assume, during the check fluid level, I should use the TC (assumed to be TC/higher temp) temp rather than the lower temp?

 

I go with the pan temperature.

 

Ok. Thanks

 

@gearcruncher

 

I’m going with pan.
As the fluid heats up, it expands.
It expand and drains out of the PAN.

 

Ok makes sense.

 

AT temp 1, is the correct unit. So which ever is listed first, I believe its closer to converter.

 

Ok so AT temp 1 for me always shows the lower side. So go off of that? I thought the higher temp would be closer to the convertor

 

I can't verify where the sensor is, it's buried inside and never fails, but I can verify that its AT Temp 1. 100%

Fahrenheit is so odd. It's 35-45C for us, 40 is the sweet spot haha.

You should not be dumping at 115, that is incorrect.

It is 97-115F

Double check my response, don't trust strangers. But 105 is the "ideal" temp to do the check.

 

The manual says,
The fluid temperature must be between 46°C (115°F) and 56°C (130°F) to accurately check the fluid level.



I get so frustrated with the temp check mode, I’d pretty much just go with “if it was running fine before I drained it, I put back the same amount that came out.”

No, this isn’t correct. But I don’t have a scanner capable of monitoring trams temps. and the “on board” procedure is monotonous.

 

Ok, so to be crystal clear here. 105 on AT temp 1 is my check temp, correct?

And yes, the 115-130 is on the how to's in the stickies section. Bad information then. And a quick search I've come across this post:
https://www.tacomaworld.com/threads...or-checking-fluid-level.462906/#post-13773547

 

If you want to know for sure, use the temp check mode built into the truck.
It uses the trans temp light to verify correct temp.

Have fun with that, 50/50 success rate for me.

 

Rightttt, but that check light comes on from a temperature. I am asking which one, and I'm sure the techs who have scan tools that show the temps aren't doing the dash light check.

 

So I have access to factory manuals but I can't share from directly for legal reasons.

I can tell you that you pull the plug between 97 and 115, anything higher is wrong and will result in low fluid level.

I don't do the dash light check, I use my techstream, I don't even know how to do the light check haha.

 

This thread which I thought used to be stickied and doesn’t seem to be so anymore, has been the authoritative thread on the matter for a while. It states the range is between 115 and 130 deg F. I have no idea if that’s true because I put the truck into temp check mode and never measure the pan temp. But it seems like that stated range would have been corrected by now if wrong.

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

97 seems super low, in the summer your pan would be at that temp in the middle of the day with the engine off outside.

Anyway I’d be interested to know what the definitive answer is.

 

I can tell you what one it uses. But I can’t tell you that it will help you.
See page 11 & 12 here.
https://atracom.blob.core.windows.net/webinars/import/toyotaa750_a761_introduction.pdf

 

Ok, well based off of that post that I linked which shows a picture instructions are for A/T Oil Temperature 1. So that is what I will go with on my gauge to get to 105.

 

I would take this guys word. He’s a Toyota Tech.


And you are lucky, that fancy Toyota scanner must be nice.
Here I am, jamming paper clips in the DLC.

 

Ah, that's good info for at least telling you what 1 and 2 do. But now it say AT temp 2 is the one to use lol!

 

I can't quote Toyota manual information directly due to legal reasons, but I can tell you I'm looking at it and its 100% 97-115F AT Temp 1.

I've done probably 500 AT changes, and its 40C or 105F on all Toyotas. Even CVT's.