How to Add Automatic Temperature Control (ATC) to a Manual Temperature Control Truck

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pw_amos

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Hey folks. Wanting to convert a 2020 2500 Power Wagon to single zone ATC. I currently have a 8.4 but have MTC. I realize this thread it for 4th gen trucks but haven't found much for the 4.5 gen HD trucks.

I assume I need a temp sensor for the knee bolster, a new sun load sensor and bezel/controls (optional?). Anyone point me to something specific to the 2019+ HD trucks?
 

rixter99

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Hey folks. Wanting to convert a 2020 2500 Power Wagon to single zone ATC. I currently have a 8.4 but have MTC. I realize this thread it for 4th gen trucks but haven't found much for the 4.5 gen HD trucks.

I assume I need a temp sensor for the knee bolster, a new sun load sensor and bezel/controls (optional?). Anyone point me to something specific to the 2019+ HD trucks?
PM M2 Mods in the Preferred Vendor section of the forum...
 

Mpgrimm2

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Hey folks. Wanting to convert a 2020 2500 Power Wagon to single zone ATC. I currently have a 8.4 but have MTC. I realize this thread it for 4th gen trucks but haven't found much for the 4.5 gen HD trucks.

I assume I need a temp sensor for the knee bolster, a new sun load sensor and bezel/controls (optional?). Anyone point me to something specific to the 2019+ HD trucks?
This is not something I'm currently offering/working on.


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Earl Zeis

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Does everyone that converted to single zone ATC get a fault code in the HVAC module for passenger side blend motor? I'm getting the fault unless I put it back to single MTC. Is this to be expected? If the system is set to single zone ATC, I wouldn't think it would look for the passenger side blend motor. I don't recall the fault code but was a U code.

Any way to confirm the sun sensor ATC circuit is fictional? I added the harness from the sun sensor to the hvac connector. As well as a 4 pin sun sensor. I have no codes for it, so I can only assume it's active and being used.



Thanks,
Earl
 

crash68

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Does everyone that converted to single zone ATC get a fault code in the HVAC module for passenger side blend motor? I'm getting the fault unless I put it back to single MTC. Is this to be expected? If the system is set to single zone ATC, I wouldn't think it would look for the passenger side blend motor. I don't recall the fault code but was a U code.

Any way to confirm the sun sensor ATC circuit is fictional? I added the harness from the sun sensor to the hvac connector. As well as a 4 pin sun sensor. I have no codes for it, so I can only assume it's active and being used.
It's possible the code is being set when you change the HVAC to Dual ATC first then to Single ATC. Truthfully I never looked for any faults and the system works fine. U codes are communication codes.
As for the sun sensor, half of it is used for auto-headlights. For other half, a couple of people on here think it does make the system change when the vehicle is in bright sun.
 

Earl Zeis

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It's possible the code is being set when you change the HVAC to Dual ATC first then to Single ATC. Truthfully I never looked for any faults and the system works fine. U codes are communication codes.
As for the sun sensor, half of it is used for auto-headlights. For other half, a couple of people on here think it does make the system change when the vehicle is in bright sun.

The fault comes right back after clearing it. So it isn't from changing from mtc to dual atc to single atc.

Yes, all ATC systems use sun load sensors. Have since the 80's that I've seen on variety of US and import vehicles. It's part of how it controls comfort. Which is why I swapped in the 4 pin sensor and ran the two wire harness so the hvac could use the sun load part of the sun/light sensor.


Earl
 

Mpgrimm2

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Earl,
I'll try and give you a call to discuss further when I get back up before with today ... Finally getting this sinus infection under control where I can talk half decent again.


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Mpgrimm2

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Does everyone that converted to single zone ATC get a fault code in the HVAC module for passenger side blend motor? I'm getting the fault unless I put it back to single MTC. Is this to be expected? If the system is set to single zone ATC, I wouldn't think it would look for the passenger side blend motor. I don't recall the fault code but was a U code.

Any way to confirm the sun sensor ATC circuit is fictional? I added the harness from the sun sensor to the hvac connector. As well as a 4 pin sun sensor. I have no codes for it, so I can only assume it's active and being used.



Thanks,
Earl
I don't have my 4th gen anymore to check but I'm betting this is a side effect of running Single Zone ATC and I'm not sure if @Ricks Ram or @STecoD remember if they had that code leftover or not before they fully converted to Dual Zone ATC.

Keep in mind the following...
Code:
NOTE: Single Zone ATC is an unofficial Ram HVAC mode and is dependent on 3rd party vehicle BCM programmers ( AlfaOBD, OBDgenie, etc.) to function correctly after programming changes made by the end user/owner. Correct operation cannot be guaranteed.

I recently converted over my parents 14 bighorn 1500 from a factory RA3 to Single Zone ATC and installed a UAQ, so the next chance I get I will check for any codes (not sure if they have the 4 pin sun sensor wiring or not yet)


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Earl Zeis

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I don't have my 4th gen anymore to check but I'm betting this is a side effect of running Single Zone ATC and I'm not sure if @Ricks Ram or @STecoD remember if they had that code leftover or not before they fully converted to Dual Zone ATC.

Keep in mind the following...
Code:
NOTE: Single Zone ATC is an unofficial Ram HVAC mode and is dependent on 3rd party vehicle BCM programmers ( AlfaOBD, OBDgenie, etc.) to function correctly after programming changes made by the end user/owner. Correct operation cannot be guaranteed.

I recently converted over my parents 14 bighorn 1500 from a factory RA3 to Single Zone ATC and installed a UAQ, so the next chance I get I will check for any codes (not sure if they have the 4 pin sun sensor wiring or not yet)


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Thanks Mike! They system seems to work correctly, though I haven't had any long trips. I'm assuming it's nature of the beast of single/dual ATC without dual ATC. Just wanted to make sure.

Today I plan to unplug my sun sensor and see if it trips a code to see if it's being seen. Just want to make sure I didn't screw up the wiring connections and locations.

Sorry I wasn't able to take a call. I did get those 2 VFD's installed.


Thanks,
Earl
 

Ricks Ram

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Thanks Mike! They system seems to work correctly, though I haven't had any long trips. I'm assuming it's nature of the beast of single/dual ATC without dual ATC. Just wanted to make sure.

Today I plan to unplug my sun sensor and see if it trips a code to see if it's being seen. Just want to make sure I didn't screw up the wiring connections and locations.

Sorry I wasn't able to take a call. I did get those 2 VFD's installed.


Thanks,
Earl
Neither STecoD or myself had any passenger blend door fault codes after switching to Single Zone ATC. The only code we had was for the Sun Sensor which went away after we installed the 4 pin version. My truck is a 14 and his is a 15. Both trucks had the wiring for the 4 pin sensor from the factory and we were running RA4 radios in both trucks. We have both upgraded to Dual Zone ATC now and still have no faults. I can't see the year of your truck or what radio you are running but that may be why yours is keeping the code due to possibly running a different HVAC module than we are.

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Earl Zeis

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Neither STecoD or myself had any passenger blend door fault codes after switching to Single Zone ATC. The only code we had was for the Sun Sensor which went away after we installed the 4 pin version. My truck is a 14 and his is a 15. Both trucks had the wiring for the 4 pin sensor from the factory and we were running RA4 radios in both trucks. We have both upgraded to Dual Zone ATC now and still have no faults. I can't see the year of your truck or what radio you are running but that may be why yours is keeping the code due to possibly running a different HVAC module than we are.

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2018 3500 tradesman. Factory 5.0 touch screen. Factory back up camera and rear parksense.

Radio is a brand new UAQ. Module is a branded new and what a 2018 with ATC calls for, part number 6866553AA.

HVAC bezel is Mike's custom single zone ATC.


Thanks,
Earl
 

Mpgrimm2

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2018 3500 tradesman. Factory 5.0 touch screen. Factory back up camera and rear parksense.

Radio is a brand new UAQ. Module is a branded new and what a 2018 with ATC calls for, part number 6866553AA.

HVAC bezel is Mike's custom single zone ATC.


Thanks,
Earl
This may just come down to an issue with the programming changes done via AlfaOBD, either the steps taken to program or a sw glitch/update. Hope to catch up with you by phone sometime when we're both available.


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Earl Zeis

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Does everyone that converted to single zone ATC get a fault code in the HVAC module for passenger side blend motor? I'm getting the fault unless I put it back to single MTC. Is this to be expected? If the system is set to single zone ATC, I wouldn't think it would look for the passenger side blend motor. I don't recall the fault code but was a U code.

Any way to confirm the sun sensor ATC circuit is fictional? I added the harness from the sun sensor to the hvac connector. As well as a 4 pin sun sensor. I have no codes for it, so I can only assume it's active and being used.



Thanks,
Earl

Update. I'm in the middle of swapping from single ATC to MTC to Dual and back to single ATC. To see if that clears up the passenger side blend door fault. I will update my findings.

I disconnected the sun sensor and that caused 3 or 4 faults. Plugged it back in and they cleared. So that confirms it's wired correctly and the system is seeing it.

Thanks,
Earl
 

Earl Zeis

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Update. I'm in the middle of swapping from single ATC to MTC to Dual and back to single ATC. To see if that clears up the passenger side blend door fault. I will update my findings.

I disconnected the sun sensor and that caused 3 or 4 faults. Plugged it back in and they cleared. So that confirms it's wired correctly and the system is seeing it.

Thanks,
Earl

Update, after going from single ATC back to MTC, then to dual and back to single, I still get the passenger B11C8 blend door fault. The only time I don't get it is in MTC. I'm guessing it's the nature of the beast. Seems to work correctly otherwise. Rather have no codes, but what do ya do?


Earl
 

SeppW

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I did the MTC to ATC mod over a year ago and it went pretty smooth. MPGrimm2 provide the harness, temp sensor, and made necessary mod/integration of the OE MTC HVAC controller to a single zone ATC. Pics attached show bezel and single zone ATC on-screen controls, temp sensor in the knee bolster, and the location of the 20 AMP radio fuse. Installation requires a harness to interconnect the HVAC module, located under right side dash and accessible by removing right side kick panel, the temp sensor located in the knee bolster, and finally connecting to the back of the HVAC control module on bezel. I had an issue when adjusting temp by holding down the switch, the temps would appear in counters on both sides of screen like a dual zone system. Further discussion with MPGrimm2 resulted in returning all back to OE config and then run the procedure again, this time removing the fuse between config changes with Alpha OBD. In the end it did not work. So if the temp switches are pressed and held until desired temp is reached, it shows on both sides in radio display. If switches are pressed and released to increase/decrease temp a single number at a time, then only the left side counter shows in display.

Changing to ATC is a matter of convenience. Set the temp and system maintains set temp by adjusting the heating, cooling, fan speed, blend door, and vents as needed to maintain set temp. You can always override, return to ATC, or run manual. With MTC only, what ever is set is what runs continuously until you change a setting in temp or fan speed.

Radio Display with Sigle Zone ATC.gif Knee Bolster with ATC temp sensor.jpg Radio Fuse '16 RAM 2500.png
 

Mpgrimm2

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Update. I'm in the middle of swapping from single ATC to MTC to Dual and back to single ATC. To see if that clears up the passenger side blend door fault. I will update my findings.

I disconnected the sun sensor and that caused 3 or 4 faults. Plugged it back in and they cleared. So that confirms it's wired correctly and the system is seeing it.

Thanks,
Earl

Update, after going from single ATC back to MTC, then to dual and back to single, I still get the passenger B11C8 blend door fault. The only time I don't get it is in MTC. I'm guessing it's the nature of the beast. Seems to work correctly otherwise. Rather have no codes, but what do ya do?

Earl

Logged in and checked my mom's 14ram1500 Bighorn (with a factory 14-17 RAx 1500 hvac module) that had the Single Zone ATC Upgrade done 3 weeks ago.

Had a few leftover codes from pervious Programming (LED Headlight and UAQ/Atc Upgrade)... Key in run, truck not running . . . Connected to HVAC module (vs BCM) and cleared codes, connected to BCM & cleared codes. Shut truck off, let it sleep. Restarted...

Only codes we got were for the left/right Sun Sensor code which was expected. I'll get it swapped out later since wiring is there for the upgraded version.
Will recheck for codes again this week but not seeing the blend door code on her truck.


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Earl Zeis

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Logged in and checked my mom's 14ram1500 Bighorn (with a factory 14-17 RAx 1500 hvac module) that had the Single Zone ATC Upgrade done 3 weeks ago.

Had a few leftover codes from pervious Programming (LED Headlight and UAQ/Atc Upgrade)... Key in run, truck not running . . . Connected to HVAC module (vs BCM) and cleared codes, connected to BCM & cleared codes. Shut truck off, let it sleep. Restarted...

Only codes we got were for the left/right Sun Sensor code which was expected. I'll get it swapped out later since wiring is there for the upgraded version.
Will recheck for codes again this week but not seeing the blend door code on her truck.


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Thanks Mike. Wish I could say the same for my truck. Lol If I recall the code clears with the HVAC off and comes back when it's turned on. Either way the only way to keep the code from coming back is in MTC, on my truck.


Thanks,
Earl
 

bigdodge

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I've been having this issue add well and can't seem to find any solution for it. Pretty frustrating to not be able to change settings for the first 30 sec

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