Use Case: Getting ATC to work on an MTC 5th Gen truck

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djcwardog

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This applies to my 2019 Tradesman 2500 6.4 gas, 4x4, regular cab. I got and retrofitted a UAX 12” radio from infotainment.com but they have yet to fix my inop climate controls. They sent me the knee panel temp sensor and a 3’ pigtail of 4 wires from its plug, but no proper harness or more details as of yet.

From a related thread on the 4th Gens, https://www.ramforum.com/threads/ho...nual-temperature-control-truck.103456/page-34

See post #838 on page 34 and Mpgrimm2 reminded us that the information from that “thread is for the 4th gen 13-18 trucks and is pretty much useless to both you and Infotainment (where I got my 12” UAX retrofit). You aren't going to be able to just drop in their previous 4th gen attempt at ATC wiring fix on the 5th gen trucks without digging through the schematics.” He went on to say that “...a quick check of the Mopar DCC tools connector repair site (free) for 2019 DJ 2500 5th gen truck shows right away that the HVAC Module/connectors are completely different than the 4th gen. So the 5th gen trucks are going to have to be figured out from scratch to do it correctly.”

Later he looked into it for us. After providing the three documents saved and attached here for clarity, he added: “Looks like the actual cabin temp sensor is the same connector as before.... You just need to get it tied into the C2 connector at the HVAC module....”.

In the post after that, between Ricks Ram and Joe Campanella, I hope I’ve understood that the 5th gen 2500 uses a single speed HVAC compressor like the 4th gens and not a variable one like the 1500's. As such, I hope that my 2500 will not need a humidity sensor to get ATC to function.

I replied there: It appears that the pins on the 4-wire sensor plug do the same things in the same order 1-4 as on a 4th gen. The 8-wire C2 looks to seek three of the four so switched 12v power could be found nearby on pin 1 of the big C1 connector with its 36 pins.

If I hold the sensor harness and wish to route its four wires, then perhaps sensor pin 1 to pin 5 on C2, sensor pin 2 to pin 6 on C2, sensor pin 3 to pin 1 on connector C1, and sensor pin 4 to pin 2 on C2. If there is already a ground wire there then splice into existing wire?

My HVAC module and its plugs at the C1 and C2 connectors are supposed to be both down at the right in the cab, just above the passenger’s feet. I will confirm when I can get this one done. My two photos show the new temperature sensor and where it needs to go above the driver’s knee in my 2500.

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djcwardog

djcwardog

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I attempted some coding last night. Bottom line: The UAX screen only responds to the Dual Zone ATC choice. Single Zone ATC or MTC choices result in the screen going instantly to “Climate Control Off” and no way to turn it on. So I’ll have to proceed along the route of installing a temperature sensor - that I already have.

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All the HVAC choices appear when you click the pull down. Only “Dual Zone ATC” works though!

0D0CC1EE-D6DE-4205-967A-829635006F6B.jpeg
This is the main screen of AlphaOBD that I had working to code my truck.


And here’s a schematic that Jimmy07 shared with us on the UAX retrofit post I started.

4BE2283D-9B69-4F2E-99FC-053F94A80105.jpeg
He mentions that the HVAC module is #6 in the view with the blower motor being #9 for reference.
 
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g00fy

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Following, getting ready to trade my 2015 1500 Ecodiesel for a 2019 cummins, but since i'm gonna be on a tight budget probably going to have to go with a tradesman and upgrade it little by little, but first things on the list are gonna be ATC & Android auto.
 
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djcwardog

djcwardog

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Looks like I am putting this particular mod on hold. Infotainment is doing an RMA on my UAX 12” kit so my original 5” UAA and MTC are going back in the truck!
 

g00fy

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What's wrong with your UAX? Also did you make a thread about your fog light install? I'll probably be doing the same thing.
 
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djcwardog

djcwardog

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I put a UAM 8.4” in the truck. That allows me to keep the manual climate controls but still get the larger screen. Details are in the 12” UAX thread linked above.
 
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