Transmission Overheating - anyone else?

[Yousef]

Here is what I found so far for our 8 speed trannys:
For the 2024-2025 Toyota Land Cruiser 250 (LC250) with the 8-speed automatic transmission, typical transmission fluid temperatures under various conditions are as follows:


Normal highway driving:

• ~150-180°F (65-82°C)

Moderate off-road trails / mild inclines (without 4LO):

• ~180-210°F (82-99°C)

Steep uphill trails, slow crawling, sand, or heavy throttle without using 4LO:

• Temperatures can rise to 220-240°F (104-116°C), especially if you remain in higher gears without the torque multiplication and cooling benefits of low range.

Warning range:

• Above 250°F (121°C) risks fluid degradation and potential overheating warnings or limp mode engagement.
• Toyota generally considers 260°F (127°C) critical for their recent 8-speed units.

This is exactly my experience here and we live in hot desert climate on the highway doing 145kmh/90mph transmission temperatures is around 92C range and highest I've seem during sand driving in hi range is 115C with outside temperatures around 40C.

During highway high speed test I've done doing the maximum speed 180kmh 'GPS speed 172kmh' , while outside indicated temperatures was 48C the transmission temperatures reached 102C .

Car is 2.8 diesel variant.

 

[ultane]

This is exactly my experience here and we live in hot desert climate on the highway doing 145kmh/90mph transmission temperatures is around 92C range and highest I've seem during sand driving in hi range is 115C with outside temperatures around 40C.

During highway high speed test I've done doing the maximum speed 180kmh 'GPS speed 172kmh' , while outside indicated temperatures was 48C the transmission temperatures reached 102C .

Car is 2.8 diesel variant.

How did you get that blue screen with all the data to display?

 

[Yousef]

How did you get that blue screen with all the data to display?

It's an aftermarket android headunit linked to an obd2 adapter through Bluetooth with Car Scanner app running.

 

[jarussell4]

You can buy a OBD2 Bluetooth and use carscanner and it will display on your screen with the carplay

 

[jarussell4]

Hello All,
Hate to report that I still get abnormal high temps on the LC. Just going up to Idylwild, CA (Moutains near L.A. and SD) from San Diego through regular road it went all the way up to 240F by the time I arrived to my destination. Has also climbed up to 230F while in our Colfax, CA Trip on the Intersate 80 going up the Sierra Nevada. There is definately something wrong with this thing. I am sitting at 3800 miles, so I will wait to the first service to let the Dealership know that I am still having temp issues. Though iy has not thrown any messages, the temp gauge gets up there and what worries me the most is that sometimestimes it shows a little over half and the temp on my carscanner (directly from the sensor) is above 220F. This can not be normal In contast, my wife's 2025 Prius had no problem going up to Idylwid and the temp on the prius was 198F by the time we got to the top....I should have kept the Jeep

 

[berry802]

Hello All,
Hate to report that I still get abnormal high temps on the LC. Just going up to Idylwild, CA (Moutains near L.A. and SD) from San Diego through regular road it went all the way up to 240F by the time I arrived to my destination. Has also climbed up to 230F while in our Colfax, CA Trip on the Intersate 80 going up the Sierra Nevada. There is definately something wrong with this thing. I am sitting at 3800 miles, so I will wait to the first service to let the Dealership know that I am still having temp issues. Though iy has not thrown any messages, the temp gauge gets up there and what worries me the most is that sometimestimes it shows a little over half and the temp on my carscanner (directly from the sensor) is above 220F. This can not be normal In contast, my wife's 2025 Prius had no problem going up to Idylwid and the temp on the prius was 198F by the time we got to the top....I should have kept the Jeep

What are you using to read the trans temp?

 

[jarussell4]

What are you using to read the trans temp?

CarScanner with a bluetooth OBD

 

[berry802]

CarScanner with a bluetooth OBD

Do you know if that is the torque convertor sensor its reading?

 

[LunarCruiser]

I live in Phoenix and off-road in 4-LOW in 100+ for hours, as well as make the climb up the I-17 from Phoenix to the high country with no issues going 85 mph. Hopefully you take it in so they can actually pull the data on it.

 

[lcq]

They sure do seem to run hot.

231.8 F Transmission fluid temp (per Carista app. PSA - don't buy this app if you're offline a lot. It logs you out automatically and requires cellular connection to log back in).

Pics were taken at the top of Imogene Pass. Transmission is always 210-235 for me in 4 Lo driving. Outside temp at this elevation is cool - around 55F. I never hear the fan speed increase to cool the transmission down. I can't decide if everyone's LC is similar to these temps and not many obsess over their trans temp gauge, or if some have a transmission cooling problem. Mine has been like this since Day 1. Taken to dealer after one overheat warning message episode, and dealer said it did not throw any codes so there was nothing they could see.

If driving close to highway speeds air flow seems sufficient to keep it operating in a normal range of 200-215F.

1958 edition. 04/2024 build date. 275/70/18 KO3's and a Front Runner roof rack are the only modifications.

My hunch is there's some issue with it kicking up the speed of the electric fan to aid in cooling, but it's only a hunch.

 

[jarussell4]

They sure do seem to run hot.

231.8 F Transmission fluid temp (per Carista app. PSA - don't buy this app if you're offline a lot. It logs you out automatically and requires cellular connection to log back in).

Pics were taken at the top of Imogene Pass. Transmission is always 210-235 for me in 4 Lo driving. Outside temp at this elevation is cool - around 55F. I never hear the fan speed increase to cool the transmission down. I can't decide if everyone's LC is similar to these temps and not many obsess over their trans temp gauge, or if some have a transmission cooling problem. Mine has been like this since Day 1. Taken to dealer after one overheat warning message episode, and dealer said it did not throw any codes so there was nothing they could see.

If driving close to highway speeds air flow seems sufficient to keep it operating in a normal range of 200-215F.

1958 edition. 04/2024 build date. 275/70/18 KO3's and a Front Runner roof rack are the only modifications.

My hunch is there's some issue with it kicking up the speed of the electric fan to aid in cooling, but it's only a hunch.

View attachment 43849
View attachment 43850
View attachment 43851

Very similar experience. As well as the comments from the dealer. Exactly the same. With the exeption that mine is still in stock tires. My hunch is that it has the same problem as the Tacomas and Tundras that the Torque Converter is not locking up when it has to, which will also explains why it feels jerky when braking. My worry is that if this is normal, we will be having to change trannys when the warranty is out (I purchased a 10/100K miles). This are not normal temps for any transmission. In 4 LO things seems to coll down on mine to 220F or so. But just to give you an idea, I did the exact same Imogene pass on my Jeep Rubicon 4xe in 4auto on the summer of 2023 (basically 4HI on demand) and the temps never went over 200F. Did Rim Roccker on 4x2 and it didn't even reach 190F. This is not Normal

 

[Bad1975]

Do you know if that is the torque convertor sensor its reading?

It's more than likely pan temp reading, most OBD devices on Toyotas read pan temp and require a special PID for the other sensor to be read.
When driving offroad if I see my temps rise while in 4HI I just put it in manual shift and select the proper gear. Temp drops rather quickly when doing this. Seems to me when in 4HI in auto shifting it is selecting two high of gear allowing torque convertor slip and is what is causing the temps to rise. I've never seen an issue, on pavement or in 4LO.

I'll bet the OTT tune might address this as it has improved shifting on various other Toyota vehicles with issues in the past.

Also, just FYI if people don't know the trans temp will never drop lower than the coolant temp except when first started up (heat exchanger is connected to the coolant loop), the trans cooler has two functions (cooling in summer and warming for winter). I believe that on the 250 it is actually integrated inside the radiator and not stand alone.

 

[jarussell4]

I live in Phoenix and off-road in 4-LOW in 100+ for hours, as well as make the climb up the I-17 from Phoenix to the high country with no issues going 85 mph. Hopefully you take it in so they can actually pull the data on it.

4LO I do not have any issues, neither on 80mph, is when going up steep hils that do not require 4LO bc you are going 15-35mph just like civics, sentras, prius, RAV4's, Rouge's, Subarus, Jeeps (of all tipes) and others do just fine and their temps I bet never reach near 230 (Saw it with my wife's prius). The other issue is on freeway on steep hills (like hwy 80 up to the Sierra Nevadas) when there is heavy traffic and you are going from 10-55mph back and forth as the traffic stops and goes. I already went and they pulled the data at 1000 miles and they did say that TC did show sliping at times, but that was normal (maybe for Toyota 240F in a tranny is Normal). I will take it again at its 5K service and will post. For now I will keep recording and taking pics of everytime it goes over 220F on easy stuff.

 

[jarussell4]

Do you know if that is the torque convertor sensor its reading?

Unfortunately the LC 250 only has one sensor that can be read with our OBDII scanner on the Tranny Pan, but not at the TC. Weird.

 

[Bad1975]

Unfortunately the LC 250 only has one sensor that can be read with our OBDII scanner on the Tranny Pan, but not at the TC. Weird.

There are two sensors, you have to have the correct PID to read the second TC sensor. It can be done with the Scan gauge, I don't remember the correct PID but it is the same as other Toyota models IIRC just don't remember which one.

 

[jarussell4]

It's more than likely pan temp reading, most OBD devices on Toyotas read pan temp and require a special PID for the other sensor to be read.
When driving offroad if I see my temps rise while in 4HI I just put it in manual shift and select the proper gear. Temp drops rather quickly when doing this. Seems to me when in 4HI in auto shifting it is selecting two high of gear allowing torque convertor slip and is what is causing the temps to rise. I've never seen an issue, on pavement or in 4LO.

I'll bet the OTT tune might address this as it has improved shifting on various other Toyota vehicles with issues in the past.

Also, just FYI if people don't know the trans temp will never drop lower than the coolant temp except when first started up (heat exchanger is connected to the coolant loop), the trans cooler has two functions (cooling in summer and warming for winter). I believe that on the 250 it is actually integrated inside the radiator and not stand alone.

I have shifted to manual and it helps a lot, it actually keeps it right at 220F or below. But in a regular twisty paved road up a mountain town I should not have to do this. I have owned over 15 cars and have never had to manually shift up mountain paved roads.

 

[jarussell4]

There are two sensors, you have to have the correct PID to read the second TC sensor. It can be done with the Scan gauge, I don't remember the correct PID but it is the same as other Toyota models IIRC just don't remember which one.

OK, thank you for the info.

 

[Bad1975]

TXD - 0701221AAA
RXF - C462051A36AA
RXD - 3008
MTH - 00090005FFD8

Can you try these for sensor 2?

• 0701221AC0
• C462051A36C0
• 3008
• 00090005FFD8

Sensor 1 on all other Toyotas is Pan temp and sensor 2 is TC.

 

[4159peter]

I wanted to share my experience with the community in case others are having similar issues.

My Land Cruiser (1100 miles) is reporting overheated transmission fluid under certain conditions that my service center has been unable to replicate and therefore do anything about especially with the absence of any thrown codes.

On relatively slow (10-45 mph) winding paved and gravel roads that head up into the mountain near me, the transmission temp gauge gradually climbs to about 3/4 of the way to the red. If I continue on a dirt road that also puts the vehicle under load at slow speeds going up a hill the gauge will eventually hit the red and I will get a message that the transmission fluid temp is high and to pull over safely. This dirt road seems to be the trigger that actually overheats the transmission. The section of off-road trail is not tough trail and does not require low-range or even locking the center diff. Kias/Subarus have been on this part of road in the past.

I currently only able to read transmission temp sensor #1 from the ECU and between 245F and 250F the vehicle is overheated. At around 235 the gauge is 3/4 of the way towards the red. At one point I watched the temp gauge, in the span of about 4-5 seconds, go from blinking red (overheated) then drop to the middle point and then move back up to just below the red all while not moving.

As another data point, I am routinely in the 200F-215F while putzing around town which seems to be on the warm side however I do not really know what the expected normal operating temp is. I have also noticed that from about 130F to 215F the transmission temp gauge remains in the middle.

I am not able to replicate this issue while driving in the city or highway driving in the mountains.

Is anyone else experiencing anything similar? I would be curious to know what temps others have been observing around town and under load like mountain or light off-road driving.

If you use low range in a situation like this you will take a lot of load off the torque converter which is responsible for the increase in transmission oil temps your talking about. If you only drive in a low speed for extended periods in hilly county low range is your friend.

 

[Sugarloafer80]

Another viewpopint. Does it freewill in neutral?
1. Lift and make sure a brake is not binding
2. Make sure CV joints are OK
3. This sounds like something causing friction and putting a load on a tranny.
4. Full tranny analysis needed.