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Discussion Starter #1
A couple of days ago I had my gauge go crazy on me and the dash started to light up and said to check transmission temperature. Also the tow haul light started a flash. I checked all of this with my torque app and I see that the temperature is very very low. Sometimes it zero sometimes it’s at 8000°. So after some research I figured it was the TFT sensor. I went ahead and replace that sensor now. However now that I have everything back together I decided to do a quick check from the gauges to see if the sensor was registering properly now before I bolted the pan back up. My OBD scanner indicates that the sensor is still reading 8123.6° it does not seem to be changing. Everything has been hooked up. Is there some other thing on this truck that Hass to be done before that gauge will register the proper temperature?

Also, yesterday when the Gage again went screwy, the truck started jumping in and out of gear and shifting incredibly hard. There was 10 secondPeriod Where the truck completely disengaged even in drive. After the temperature went up on the gauge to about 70°, the truck started shifting normally again.

Did I just waste a bunch of money on a sensor that wasn’t bad? What the hell should I do next? Can I test the old sensor?
 

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Pull the covers off the steering column and check where the tow/haul harness comes out of the stick -- it can chafe near there
 

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Discussion Starter #3
Nope. Wires are fine.

Sensor still doesn’t work. New sensor is installed. Gauge reads dead. Torque price says gauge is reading 8167 degrees. If you drive like this, it won’t shift. If you let the truck warm up you can get it to register 50 degrees and it’ll shift.

Why can’t my truck problems be simple?

What else can this be?
 

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The sensor wires to the PCM, so check the harness -- especially near the PCM where the transmission harness comes up

The sensor reads with the engine off, key on -- so you can lay under the truck and check the harness while watching Torque for changes
 

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Discussion Starter #5 (Edited)
Those wires on the driver side are all great. No movement or wiggling changed anything. Still readin 8167.3 degrees.

How is this even possible? One day fine. One day not. Such is the story of the 6.0.

Still looking for help.

Old sensor tested out at 30kohms at 70 degrees or so and changes when I warm it up. That sensor is fine.

I checked for chafing wires on the sensor itself and I did not see anything. You can only check a few wires though.

What’s next?
 

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Discussion Starter #6
If this sensor works like other ford sensors then resistance goes down when temperature goes up. So in order for me to get 8,000 degrees, it needs nearly no resistance. To me, that points to a chafed wire shorting to ground and it must be inside the transmission. Not sure how to pull that harness out of the trans though.
 
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