2014 3500 Aisin p2742

[N8dogg]

I’m getting a cel p2742 tft circuit b low and trans temp too hot warning light. temps are in the 160-170s no issues with shifting. Any help would be great not much out there on this.

 

[PRS]

Here is what it says for a 2020 3500 with Aisin. So basically the circuit is monitored all the time. The resistance value of the circuit at 77* F should be 3437 ohms and at 230*F should be 247 ohms. So as the temp goes up the resistance goes down which means the monitored voltage goes down. Probably a short in the circuit to ground or to a near by circuit. The sensor circuit is pin 22 & 23 of the TCM connector. Check the circuit resistance itself and then for continuity to ground or any other circuit. Hope this helps.
Now that I think about this, you said temps are 160-170s. If that's the case how can you have a high temp warning?
--More--
So there are two temp sensors in the transmission according to the wiring diagrams. Your DTC deals with the circuit I mentioned on 22 & 23. There is another sensor in the solenoid pressure switch assembly.
I'll be back.

 

[PRS]

So, your P2742 deals with fluid temp sensor 2 which is the torque converter fluid temp sensor. The other temp sensor is Fluid temp sensor "A" which measures sump temperature and is where the temp display comes from. The two sensors are used together and compared to monitor for specific conditions related to transmission operations.
The P2742 points to a short in the sensor 2 circuit that draws the voltage below .059 for a specific period of time. Thus, we're looking for shorts to ground or another circuit. I know.....TMI but it was bugging me how you could have a normal temp display and still have that DTC.
My apologies if none of this applies to your 2014.

 

[Topzide]

Just PM'd you some info. hope it helps.

 

[N8dogg]

So, your P2742 deals with fluid temp sensor 2 which is the torque converter fluid temp sensor. The other temp sensor is Fluid temp sensor "A" which measures sump temperature and is where the temp display comes from. The two sensors are used together and compared to monitor for specific conditions related to transmission operations.
The P2742 points to a short in the sensor 2 circuit that draws the voltage below .059 for a specific period of time. Thus, we're looking for shorts to ground or another circuit. I know.....TMI but it was bugging me how you could have a normal temp display and still have that DTC.
My apologies if none of this applies to your 2014.

Thanks for info

 

[N8dogg]

Just PM'd you some info. hope it helps.

That for sure will come in handy I’ll post what I find

 

[sag2]

Don't know what year your truck is, but there may be a connector just below the drivers feet that is going to the transmission. It is under the wheel splash shield and if the weather pack seal is not good it can corrode the terminals. Especially in salt belt areas.

 

[N8dogg]

Don't know what year your truck is, but there may be a connector just below the drivers feet that is going to the transmission. It is under the wheel splash shield and if the weather pack seal is not good it can corrode the terminals. Especially in salt belt areas.

2014