I bought Torque Pro and an adapter specifically to read my Automatic Transmission Fluid temp. I need to be able to monitor it in order to do a proper service as the fill needs to be in a specific range. I have added the GM specific PIDs. From here I test each one and only GM Method 2 comes back with a value. However, the default equation is A-40 so it is showing my ATF temp is -41. It should be around 100F now. The car is a 2005 Cadillac STS. I would appreciate any help to tell me how to get the proper Fahrenheit reading. Thanks in advance.

Quote from emamon on January 17, 2017
Still looking for ANY help.

My car has 5 speed auto tranny. Pretty convinced that the PID of 221940 is correct. The OBD header of 7E2 is the only one that tests with any results.

Can anyone at least help me to understand the logic of equations and how that should be set. Being a noob, I would expect just to read the value and have no equation. What does A-40 or A*(9/5)-40 do???? I seem to be apply an equation to a queery result of -1….

End Quote.

A-40 is a typical equation for °C.
A*(9/5)-40 for °F.

Torque will convert based upon your
preferred choice in settings.

While that pid works for other GM vehicles
it still may be another pid is used by your
vehicle since the results don’t make sense.

I suggest searching public sites specific to your
vehicle to see if someone has solved this
already.

Edited.

I still have not received any help on this. Can anyone tell me if it may be a function of a cheap adapter? I have not suspected the adapter as the main screen of Revs, Coolant Temp., Vacuum, etc. all worked perfectly. Could Transmission Fluid Temp be a different bus or protocol to query where the adapter is messing up? I am using this adapter https://smile.amazon.com/gp/product/B00T5G53ZM/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1