Transmission temps don’t match

[DaveMatthewsBand]

I have an OBD2 reader and a small tablet.
I use it to monitor the factory TPMS, and other values. One screen displays all 4 tire pressures. I can flip to another page and I see all the EGT sensors, transmission, oil and coolant temp.
The indicated transmission temp doesn’t match what is on the dash display.
Please see the photo below.
Can anyone explain this difference in temps?




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[jkwilson]

What was the ambient temperature when you took the picture? Truck had any reprogramming done?

[DaveMatthewsBand]

Ambient is 55F.
Truck is stock, never been in the shop 2 years I’ve owned it.


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[jkwilson]

My OBD shows “Transmission Temperature” and “Transmission Fluid Temperature” as selectable on my 250. I don’t know what the difference is.

[DaveMatthewsBand]

My OBD shows “Transmission Temperature” and “Transmission Fluid Temperature” as selectable on my 250. I don’t know what the difference is.

Hmmm...
I wonder if there is a sensor at the inlet and a sensor at the outlet side of the transmission radiator thingy?
So the higher temp is the trans fluid before it hits the radiator and the lower temp is after it's cooled?

I threw together a quick mock up of what I'm picturing, using my super expensive very complicated 3D software...

[Country Campers]

Ed
I know this is no help but , I am interested in the reader and tablet info please?

Brian

[Calbar]

I know on my Tundra that there are 2 transmission fluid temperatures. One in the pan after the cooler and another before the cooler. My temp gauge on the dash is the one in the pan so it is steady all of the time no matter what I am pulling or where. Based on what I read on the Tundra forums it is the other one that I don't see that will set off the light for high transmission temp. Yours may be the same.

Rob

[DaveMatthewsBand]

Ed
I know this is no help but , I am interested in the reader and tablet info please?

Brian

Yea no problem, I'll send you a PM.

[jkwilson]

Hmmm...
I wonder if there is a sensor at the inlet and a sensor at the outlet side of the transmission radiator thingy?
So the higher temp is the trans fluid before it hits the radiator and the lower temp is after it's cooled?

I threw together a quick mock up of what I'm picturing, using my super expensive very complicated 3D software...

Just a little googling makes me think my second number is a torque converter related temperature.

[bigb56]

Are you using a pre-defined profile from the program or did you write your own PIDs? Running Torque Pro even on my older truck I have found cases of several different PIDs for the same gauge that yields different results. We have some pretty smart guys on the FTE forums that write and share PIDs for the 7.3 and 6.0 but I've never looked in on the 6.7 forums to see if those guys are doing the same. I would bet there is more than one sensor for your transmission as well and you can bet that Ford wants you to see the coolest one, just like the early trucks with the dash gauge that didn't move off normal till you were close to 250 degrees. They don't want people clogging up the service department with perceived problems while under warranty! Same reason the check engine light only illuminates when there is an emissions related problem because that is EPA mandated, all the other recorded DTCs are stored till your next service visit, without illuminating the check engine light.