One more shouldve taken a pic question - transmission temp sensor - Toyota 4Runner Forum

BuffaloBass · 02-12-2025, 07:56 AM

Folks, once again kick myself in the heine for not taking pics.....3 ports on the auto transmission. from YOUTUBE i discern that the 1st port nearest the bellhousing area is for the temp sensor and the other two are the cooler lines?

Is that correct? THNX!

phattyduck · 02-12-2025, 04:08 PM

Quote:

Originally Posted by BuffaloBass

Folks, once again kick myself in the heine for not taking pics.....3 ports on the auto transmission. from YOUTUBE i discern that the 1st port nearest the bellhousing area is for the temp sensor and the other two are the cooler lines?

Is that correct? THNX!

It isn't 100% clear from the pictures I have, but that's what it looks like. The lines remaining in the truck should line up with things, so it will 'correct' you when you get there.

-Charlie

2TH4IST · 02-12-2025, 07:07 PM

A quick a340f image search popped this up. Matches what is on my trans when I did my new lines.

brillo_76 · 02-13-2025, 12:14 AM

The hottest point in the transmission is the nearest cooling line to the bell housing and the sensor like @2TH4IST image shows.. There is where one would plumb in aux sensors if needed. 2nd option would be on that front line.
Pre 1999 do not have a Temp sensor nor the ecu circuitry to do more then when the sensor hits a certain temperature turn on the idiot light.

BuffaloBass · 02-13-2025, 07:42 AM

THNX FOLKS! I did not want to assume, and indeed Charlie the old trans lines ( which i need to have redone) do line up with the two more rearward holes,.

THNX 2TH for the pic.

phattyduck · 02-13-2025, 12:45 PM

Quote:

Originally Posted by brillo_76

The hottest point in the transmission is the nearest cooling line to the bell housing and the sensor like @2TH4IST image shows.. There is where one would plumb in aux sensors if needed. 2nd option would be on that front line.
Pre 1999 do not have a Temp sensor nor the ecu circuitry to do more then when the sensor hits a certain temperature turn on the idiot light.

The sensor is still there with the same specs as the '99+ transmissions - the ECU just doesn't report it out via OBD-II. It still uses temperature information to control shifting operations internally, and light the idiot light, as you point out.

-Charlie

brillo_76 · 02-13-2025, 05:08 PM

Quote:

Originally Posted by phattyduck

The sensor is still there with the same specs as the '99+ transmissions - the ECU just doesn't report it out via OBD-II. It still uses temperature information to control shifting operations internally, and light the idiot light, as you point out.

-Charlie

Do you happen to know if the sensors are the same from 96 -02? As I am looking into putting another sensor in down the road for temp readings in the older 96 to 98 3rd gens.. I wish there is a way to easily pull that sensor data or parallel into it so one can just put a temperature gauge in. I am thinking they are not and why I have to plumb something else in in that area. 99+ you can just read the data out on an obd II software or like I hope to do with an andriod radio, just run it all the time on the radio screen. Most of my fleet though are 97 and 98.. Hence why I am curious..:-)

phattyduck · 02-13-2025, 06:31 PM

Quote:

Originally Posted by brillo_76

Do you happen to know if the sensors are the same from 96 -02? As I am looking into putting another sensor in down the road for temp readings in the older 96 to 98 3rd gens.. I wish there is a way to easily pull that sensor data or parallel into it so one can just put a temperature gauge in. I am thinking they are not and why I have to plumb something else in in that area. 99+ you can just read the data out on an obd II software or like I hope to do with an andriod radio, just run it all the time on the radio screen. Most of my fleet though are 97 and 98.. Hence why I am curious..:-)

PN 89429-35042 (trans temp sensor) is the same part used on ALL 4Runner and Tacoma A340s from '88 to '04, along with T100 and Tundra V6.

-Charlie