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Transmission temperature for an '05 ... tell me its true, seems to work on mine!

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I have always been told no way to get tranny temp on an '05 without adding a sensor and my previous programmer did not have it. The supported PID's for '05 do not have it listed. But, I know my truck has a "Trans Temp" warning light so it has to be reading something and the TRANS-OT is an option to turn on so I turned it on out of curiosity. Temps seem real as when cold it matches my analog transmission temp gauge in pan but as it starts to warm up is about 10-15 degrees hotter so assume it could be a sensor on a line closer to trans. Is this true tranny temp, something else, something just being calculated rather than measured?

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The '05 has a tranny temp reading supplied to the transmission control module by a thermistor. The temp readings are used to control engagement of 4the gear overdrive clutch, the converter clutch and governor pressure.

 

The thermistor is part of the governor pressure sensor assembly and is immersed in transmission fluid at all time. A thermistor is basically a resistor that changes value as it is heated and is commonly used for measurement and control.

 

There is a page (21-1140) in the service manual that talks about its function relating to transmission controls.

 

The obdII port can read this temp. I run an Edge CTS Insight connected to my obdII port and monitor this temp all the time.

 

If your Smarty touch can read this output then I would think you should be confident you are reading the internal trans temp. :thumbsup:

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This reading comes via the SCI pins on the OBD port as far as I can figure out. Obd data comes from a different set of pins in the same connector. I don't believe its available through the obdii datastream on a code reader.

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I have a 05 also with touch, I was told it takes temp from the VB, mine hits 220°-240° pulling! I hope that this is normal in that area

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I can ready trans temp with my touch on my 2005. I ran it with my gauge and touch.. Noticed a 10-20° difference

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As mentioned above I have an Edge CTS Insight that I use for gauges and I monitor trans temp via the obdII port. I rarely see temps above 200 degrees when working the truck on hot days. Highest temp I have ever seen was 240 and that was only for a few minutes within just a few hours of doing a heavy duty trans rebuild and I was pulling a small trailer in town.

 

Never seen it since.

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