CVT Temperature apps

Hi all,

 

Trying to see if I can use an app to measure the CVT temperature to help come up with a reasonable replacement interval. I have a 2021 Outback Onyx XT on order, but some difficulties lately:

 

I am currently driving a 2019 Forester. My previous car was a 2011 Outback 2.5.

 

The 2011 could access CVT temperature via an app like ActiveOBD for Subaru on Android, using my OBDLink LX with a cheapie Android phone I had on hand (with no data plan)

 

The 2019 can not display the CVT temperature.

 

Trying to find out if this is a Forester thing, an app thing, or an adapter thing. Since the Outback and Legacy are practically the same car, I figured I would ask around here too. The OB forum appears to be stumped or people don’t care at the moment since the vehicle refresh is still pretty new.

 

If my fluid temperatures are under 180F I would consider running 100k intervals. Maybe even leave it alone if it stays at 160.

Mt fluid replacement is 60k. 5eat fluid replacement is 60k. Why would you think the cvt replacement is magically 160k? Cvt fluid life has been proven, tragically, to be less than 100k. There are outliers as always. Ppl win at russian roulette, too.

Regardless of my reasons for doing so, would still like to monitor CVT temperature. Anyone have experience with the about app or Bluetooth dongle?

My '20 can display the oil temp in the top center screen, and I wonder if a Scangauge could show the transmission temperature? But for that, it needs to have a temperature sensor in it?

I'd say with certainty that there is a temperature sensor in the CVT, makes no sense otherwise.

 

Sent from my Pixel 2 using Tapatalk

 

For WRX but it's the same CVT if you have the 3.6R. Even if you don't I'm betting Subaru uses similar code and the same sensor in both the TR690 and 580.

Greetings,

 

Just as a point of reference, I have a 2020 Legacy Base 2.5NA. As you know the Legacy does NOT have the CVTF cooler installed unlike the Outback which does.

 

Here are my CVTF and Coolant temps driven on a sunny day last summer when I picked up my new car (2000 miles on it).

 

It was clear, sunny, dry day with the outside temp 93F and humidity was typically high for Texas.

 

Starting temps: CVTF: 91.4 F and Coolant: 91.4F

After 9 mi warmup at 45 mph: CVTF: 159.8F and Coolant: 194F

After 40 mi highway cruise at 65 mph (TWICE): CVTF: 199.4F and Coolant 190.4F

After 20 mi stop+go in traffic: CVTF: 201.2F and Coolant: 194F

 

All the driving was done in one outing. I did the 40 mi highway both with cruise on and the first 40 was done in manual 6th gear (~2600 rpm) then in "D" (~1800 rpm). Both times the temps were the same (only +- a few F).

 

At the end of all the testing the Oil temp was 206.6F

 

Hope this gives some insight on when to service the CVTF.

Forgot to say all the temps were taken with a scan tool connected to the OBD port by a cable.

My 2020 Legacy has a build date of 02/2020 and purchased on 06/2020.

Now 1 year old with no issues.

As you know the Legacy does NOT have the CVTF cooler installed unlike the Outback which does.

Not quite true. Legacys do have a dedicated heat exchanger, with its own thermostat, to warm/cool the CVT fluid using engine coolant. The Outback adds a second air/oil CVTF cooler in front of the radiator and A/C condenser.

 

After more than 50 K miles each in our 2015 Legacy 2.5 and 2016 Outback 2.5, the highest CVT fluid temperature ever I've observed was ~215 F ... cruising across west Texas in our Legacy at 75 mph on a 100+ degree day. In general, CVT fluid temperature seems to stabilize within +/-10 degrees of engine coolant temperature. That said, slogging along at low speeds (below ~15 mph) with the torque converter clutch disengaged ... e.g. steep off-road trails or in deep snow, mud, etc. ... is probably the worst case for CVT fluid heating. An unlocked torque converter can dump lots of heat into the CVT fluid in a very short time.

Edited May 13, 2021 by ammcinnis