Transmission Temps A750F

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Joined
Aug 30, 2021
Threads
5
Messages
19
Location
Seattle
Just installed my scangauge 2 in my GX470 that I've had for 2 months. I added the Transmission Temp X-gauge (TFT) which was a process in of itself. It turns out Toyota was in process of changing protocols between ISO/KWPS and CANSF, so I have the ISO/ KWPS protocol. None of the 4 listed on the scangauge x-gauge list works for my GX, I would get a static reading of either 194 of 350, or no reading at all. It would start with either of those readings, and never moved, so I suspected it was an error. I spoke with their support and they provided one code that is apparently hit/miss with ISO/KWPS. I input this code (below) and it seems to work. It does seem now, though, that the temps are reading somewhat lower than I expected. I expected the trans temp to be closer to the operating coolant temp readings of around 180-184 degrees, but it's reading around 138-145.

I've searched a bit and am seeing posts about "where to be worried" about transmission temps which is 200+ etc...but I've only found one LC post referring to temps similar to what I'm seeing. I'm not sure if the temp is accurate or if it's another error in reading (note: this time I am at least seeing changes in the trans temp as I drive.)

So far I've only driven locally/ non-highway so maybe that's why it's not getting over 145. I just assumed it'd be in the 170+ range.

2003 GX 470, 118k miles, all stock for now.

Here's the code for the ISO/KWPS protocol:

Transmission Temperature (Degrees F)
TXD: 686AF101B4
RXF: 044105B40000
RXD: 2808
MTH: 00090005FFD8
NAM: TFT
 
It should run the same temp as the coolant when warmed up, which is about 195F. It might run 140F when it's cold and all 15 quarts of fluid haven't been warmed up thru the radiator. I'd take it on the highway for at least 30 min and see if it goes up to coolant temps.

If you want a 2nd opinion, it can also be read via a Torque Pro ($5) on your phone and a cheap Bluetooth OBD2 adapter. You will need to type in the non-standard PID, which can be found online.
 
Mine runs about 140-150 normally, but I have a big transmission cooler installed. It’ll get up to 190-210 while towing through some hills or going into a headwind.
 
What transmission cooler are you using?
https://a.co/d/2anQRlM Is the one I have, but Amazon says it’s no longer available. I’m sure there are comparable options. TruCool had the best reviews I could find and it’s been great for the past 3 years.
 
It usually runs ambient temp plus 80-90F. So in thr summer, around 170F. I've never had it exceed 200F towing. It did get up to 225F on a long 4LO climb out in CO earlier this year. I think it would have got a lot hotter with the OEM cooler.
 
Just installed my scangauge 2 in my GX470 that I've had for 2 months. I added the Transmission Temp X-gauge (TFT) which was a process in of itself. It turns out Toyota was in process of changing protocols between ISO/KWPS and CANSF, so I have the ISO/ KWPS protocol. None of the 4 listed on the scangauge x-gauge list works for my GX, I would get a static reading of either 194 of 350, or no reading at all. It would start with either of those readings, and never moved, so I suspected it was an error. I spoke with their support and they provided one code that is apparently hit/miss with ISO/KWPS. I input this code (below) and it seems to work. It does seem now, though, that the temps are reading somewhat lower than I expected. I expected the trans temp to be closer to the operating coolant temp readings of around 180-184 degrees, but it's reading around 138-145.

I've searched a bit and am seeing posts about "where to be worried" about transmission temps which is 200+ etc...but I've only found one LC post referring to temps similar to what I'm seeing. I'm not sure if the temp is accurate or if it's another error in reading (note: this time I am at least seeing changes in the trans temp as I drive.)

So far I've only driven locally/ non-highway so maybe that's why it's not getting over 145. I just assumed it'd be in the 170+ range.

2003 GX 470, 118k miles, all stock for now.

Here's the code for the ISO/KWPS protocol:

Transmission Temperature (Degrees F)
TXD: 686AF101B4
RXF: 044105B40000
RXD: 2808
MTH: 00090005FFD8
NAM: TFT
To get back to your original post I just drove 4 hours on the highway with outside temps in the 40s and my transmission temp was 135. Got up to 150 while idling in drive but dropped back down once we started moving again. Based on @Rednexus comments and my experience about 100 degrees +/-20 above ambient in colder weather is common.

That being said I would like to get the Hayden 678 and the bellow kit to see if that helps keep the transmission temps in a narrower temperature window.


For everyone using CANSF protocol these are the codes to read transmission temp.

TXD: 07E021D9
RXF: 032180000000
RXD: 2810
MTH: 00070064FE70
NAM: whatever you want it to be
 
Thanks for that!
Just ordered the bracket, and grabbed a 698 off Amazon for $60.
I’ll be doing a trans service soon and will just do it all at once.
I plan on doing the same when I hit 160k next year. Be sure to post your thoughts on the kit and if you have a way to see your transmission temp I'm curious if it warms up any better.
 
Thanks everyone! Seems like it’s operating as it should, and will monitor as I get into warmer weather and climb the passes out here in CO. I haven’t been able to get it on the highway this week with the holidays but I’m confident I’m getting a reading as I’ve seen as low as 55 in the AM and it warms up to 130ish and have gotten it to 145 in stop and go.

Does anyone know off hand where the sensor is grabbing the reading? In the pan?
 
First time contributor but long time lurker here....

I spent a decent amount of time trialing different x-gauge settings for transmission temperatures, and I'm fairly certain I am able to read the torque converter temp and the pan temp. The two track very close on low load steady state cruising, and what I believe to be the torque converter temp reads higher when the drivetrain is under load.

As far as temps go, I have the Hayden 678 upgrade and my pan typically reads between 130-150 around town and close to 150 on steady state highway cruising. I live near the coast in Southern California, so the weather is usually very mild with minimal temp swings. With the upgraded cooler, I rarely see over 190F at the torque converter even when climbing long steep mountain roads in my area with pan temp sitting ~20F lower.

Here are the settings I'm using on my 2007 GX470.

Pan Temp
TXD: 07E021D9
RXF: 032190000000
RXD: 2810
MTH: 00070064FE70

Torque Converter Temp
TXD: 07E021D9
RXF: 032100000000
RXD: 1810
MTH: 00090005FFD8

scan gauge.jpg
 
Just for the fun of it I decided to begin covering portions of the transmission cooler with tape to see if that allowed the temps to get any higher during the winter and the results were not what I expected. I eventually covered the entire face of the cooler and it raised the average temp maybe 8 degrees in all conditions. My mechanical engineer brother in law explained despite getting minimum air flow the radiator still dissipates a good amount of heat especially when the ambient air temp is so low.

First time contributor but long time lurker here....

I spent a decent amount of time trialing different x-gauge settings for transmission temperatures, and I'm fairly certain I am able to read the torque converter temp and the pan temp. The two track very close on low load steady state cruising, and what I believe to be the torque converter temp reads higher when the drivetrain is under load.

As far as temps go, I have the Hayden 678 upgrade and my pan typically reads between 130-150 around town and close to 150 on steady state highway cruising. I live near the coast in Southern California, so the weather is usually very mild with minimal temp swings. With the upgraded cooler, I rarely see over 190F at the torque converter even when climbing long steep mountain roads in my area with pan temp sitting ~20F lower.

Here are the settings I'm using on my 2007 GX470.

Pan Temp
TXD: 07E021D9
RXF: 032190000000
RXD: 2810
MTH: 00070064FE70

Torque Converter Temp
TXD: 07E021D9
RXF: 032100000000
RXD: 1810
MTH: 00090005FFD8

View attachment 3806116
I wish the torque converter temp codes worked for me but it's not giving me accurate data.
 

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