Anyone know of a scanner that will read the temperature of the transmission for the purposes of keeping an eye on the fluid level? I have heard of other ways of measuring the temperature such as, sticking a food thermometer down the fill tube, or pulling a small amount out and measuring the temperature once a small amount of the fluid is pulled out. I had the thought to just hit the pan with a laser thermometer, but I'm not sure that's entirely accurate, especially in the winter months.

 

I’ve spent a lot of time researching possibilities on this because I’ve been wanting to do the same. There are a few options but none that I personally am willing to try right now because it’s just a convenience issue for me and I don’t have the time to keep looking - I can use the scan tool at work when needed.

What I’ve found -

1) Use a dongle and smart phone app - it was discussed in this thread - https://dodgeforum.com/forum/dodge-c...t-changes.html

2) Get a small scanner that can read live data, but I’ve not been able to verify which brands will read trans fluid temp - more research needed.

3) I contacted Dodge customer service about reprogramming the EVIC to provide it - they said it couldn’t be done which I don’t agree with but didn’t have time to argue with them.

4) Tapping into the factory signal wire and mounting a gauge on the dash. The concern here was that it could potentially affect the signal to the PCM which would affect the shift schedules, so testing and analysis during driving is necessary.

5) Installing aftermarket sensor and gauge kit - there’s a lot of debate about the location of the sensor. Options were to drill a hole in the pan, use a pressure test port, tee into the cooler lines. My issue with this is that the factory TFT sensor is part of the pressure switch and range assembly, so it’s measuring temp close to the center of the trans. I’m not convinced another location for a sensor will read close enough to the factory sensor to be accurate for the fluid temp chart, so I’d want to do more research and analysis first.

Dig, dig, dig - there’s plenty of info to find on this.

 

I read mine (2018 DGC SE Plus) with a cheap bluetooth reader and Torque pro fro android.

Click settings cog on main screen. Then Click settings (the word settings).
Then go to Manage extra PID's/Sensors.
Click 3 dots in top right of screen.
Click add predefined set.
Add all of the Dodge/Chrysler/Jeep ones.
One of these 3 will work. I use Jeep Pre 2012 ((A*256)+B)*(1/64) and successfully read mine.
You can prove it works by setting it up and using it. Then let your van sit overnight say 12-15 hours. Then you know the fluid should be equal to the outside temperature (assuming you have stable overnight temperature) then start the app with the key off but in accessory or run. Then start the van because the transmission temp will not work on OBDII unless it's running (if I remember correctly) and then you can compare the temp reading to the outside temperature.

On the list where you add new widgets you can see live readings of all the added PID's and you can see if any of the 3 transmission temp options for Chrysler give you a reasonable temperature (Outside temp up to 180F, transmission should get above 180F unless towing). My wife has a 2011 Jeep Patriot that is more Hyundai than Chrysler and the CVT in it is JTAC built. There is no way to read her transmission temp that I have found.

 

I've seen a video on YouTube where someone doing this on a Toyota where he has a scan tool hooked up and reading the transmission fluid temp. then he uses a temperature laser gun shooting the pan for comparison between the reading. Conclusion the scan tool and laser gun were within 1 degree of each other. The outside temperature should have no effect on the oil temp due to the oil pan material heat transfer coefficient it would take longer for transmission to come to temperature in cold weather but with the oil sitting at the bottom of the pan their temperature should be close to each other.

 

I do have a BlueDriver, but it doesn't seem to have the ability to read trans temperature in the app. It looks like there's only one app for bluedriver and no other alternative. I'm sort of kicking myself for not picking a dongle that has an app that's more flexible, or one that can be used with different apps. Anyways, that's good to hear about the temperature gun vs the true scan tool reading because I bought a temp gun. I didn't know how accurate it would be but figured it would be better than nothing.
Thanks for replying guys. Always appreciate the help.

 

Do you have a link to the video? Many Toyota trans temp sensors are mounted either directly in the oil pan or the valve body, which is submerged in fluid in the pan, so it wouldn’t surprise me to find that the live data and an infrared thermometer read close to each other depending on the transmission.

The 62te temp sensor is part of the pressure switch assembly behind the valve body, which is mounted above the pan on the front of the transmission. I don’t know for sure if there would be a significant temp difference or not, but when knowing fluid temp is necessary for checking the level, I wouldn’t want to assume anything until I had the chance to verify it.

 

I got an elm knockoff on Amazon for $12. I've heard there are bad ones on there but you just have to read the reviews. I've bought two off of there because I accidentally left one in a car I traded in and both of them worked just fine.

 

One would be lead to believe since transmission fluid also act as a coolant for the transmission the temp of the unit and oil would be close to each other and the pan being the collector of fluid would also be close to the transmission temp once warmed up. Since we're checking the safe operating oil level which is determine by the temperature because of it's thermal expansion coefficient and especially not to overfill.

 

So, I measured, with a quality temperature gun, the transmission filter pan at 119 degrees at multiple spots up close and further away, and the shift solenoid pan on the front of the transmission measured at 95. The transmission casing was measuring 120-122 in different areas. I split the difference, sort of, and went with 110.
What are your thoughts? What temperature would you have gone with?

 

I’m actually going to be putting the laser thermometer to the test this weekend. I need to reseal a leak on the valve body cover so I’m gonna give it a filter service while I’m at it. I’m doing the work at home but will then drive it to work (about 10 miles) so I can get the scan tool on it and will compare the reading on live data to a reading with a laser thermometer on the pan - maybe even check a few other spots while I’m at it.

As for your level check, the fluid chart shows a minimum of 8 mm for temps at and below 100F - at 120F it’s a minimum of about 14 mm, so I’d say if you’re between 8 and 14 mm you’re probably good to go.