Passenger side climate control not working

[Ben06]

2020 JTR passenger side temp control is not working right. Passes all the scan tool checks and all the actuator doors are working correctly and verified. What is happening is the passenger side heat/ac does not control the temp correctly when on floor or defrost. It seems to work correctly when using the dash vents. It will blow full hot on HI but when you try to adjust the temp lower it will start moving to full cold when you get down to around an 80 degree request. I think it might be one of the temp sensors but cannot figure out which one or what the ohm specs are to be able to test them. Any input would be greatly appreciated.

Sponsored

 

[kevman65]

@Hootbro

He's your guy, I think he has all the schematics and specs saved.

 

[Ben06]

Thanks @kevman65 I see that @Hootbro was viewing and hope he jumps in with some information. I did find one site that seemed to have a solution but the solutions were locked down to "professionals" in the field and needed to be filled in with credentials and years worked at some facility. I have "credentials" as in ASE certs and an automotive degree but do not work in the field so it would only allow me to view certain solves as a unverified guest. My daughter is getting tired of being too hot or too cold in these MN winters.

 

[Lost1wing]

This was brought up in anther thread after their JT was in a wreck. A blend door wasn't working and was replaced. That didn't solve the issue so he came here. I looked up some the the testing that needed to be done. There should be fault codes with the proper scan tool and testing procedures that can be done to calibrate the actuators.

 

[Hootbro]

Thanks @kevman65 I see that @Hootbro was viewing and hope he jumps in with some information. I did find one site that seemed to have a solution but the solutions were locked down to "professionals" in the field and needed to be filled in with credentials and years worked at some facility. I have "credentials" as in ASE certs and an automotive degree but do not work in the field so it would only allow me to view certain solves as a unverified guest. My daughter is getting tired of being too hot or too cold in these MN winters.

I just have the wiring schematics. Do not have a active Tech Authority subscription for the troubleshooting data.

@Lost1wing has better advice than I can give on this.

 

[Ben06]

Thank you all so far for the responses, @Lost1wing I do have access to a high end Snap On scan tool that I have been using. It doesn't have any fault codes and it passes all the functional tests and calibrations for all the blend door actuators and they do move accordingly. I was hoping that it was an actuator and tested them thoroughly by both watching the functional tests and by taking them over manually through the scan tool and visibly making sure they followed the requested open close commands 0-100%. I have not found a spot on the scan tool that reads each individual temp sensor (4 of them). My guess is that it is one of the passenger side sensors and probably the one that requires the dash to be removed unfortunately. I can easily get to one of the temp sensors to pull it out and test it but I don't know what the ohm/temp specification is on them nor can I find it online.

 

[Hootbro]

Do both sides work in tandem when in Sync? How about in Auto mode?

 

[Ben06]

Does the same thing if in Sync or in Auto. Works when it is on the dash vents but not on floor/deforst settings

 

[Hootbro]

Does the same thing if in Sync or in Auto. Works when it is on the dash vents but not on floor/deforst settings

When you say "floor/defrost" are you talking about the dual setting or the dedicate front window defrost only or the floor only?

 

[Ben06]

Only works correctly when it is on the direct dash vents.

 

[Hootbro]

Wish you luck then.

One of those things that is not conducive to being working through across the internet rather than having direct eyes on the problem. We could go back and forth probably with 20 more questions but things will get lost.

My spitball swing at it would narrow on the Right Floor Duct Temperature Sensor

 

[Hootbro]

Not that it is directly related, did you ever get the attached TSB done to update the HVAC controller software for the intermittent floor heat issue?

 

[Lost1wing]

FWIW on connector C1 on the hvac module, pin 30 is the common for the sensors. 19 and 20 are the right and left panel sensors, 28 and 29 are right and left floor sensors. 3k ohms at 77f see chart in the photo.

 

[Ben06]

Thanks everyone, I'll get to testing these suggestions hopefully tomorrow and let you know what I find out

 

[Ben06]

Well I had some time to contort under the dash and get the ohm readings from the sensors and although I only did it at one temperature it does not seem to show a glaring problem with the sensors.

All readings at about 75 degrees (finger in air method educated guess by combined sensor readings)

Right Panel Sensor - 2.48k Ohms
Left Panel Sensor - 3.32k Ohms
Right Floor Sensor - 3.0k Ohms
Left Floor Sensor - 3.45k Ohms

Deductively I would assume that one of the sensors on the right side would be way out of whack as this is a temperature area that the control has the issue with.

I have not had the tech bulletin update done, I believe that was an issue that was always present and I have not had any of the issues that are presented in that bulletin. (not saying they aren't hiding something else that gets fixed with it though)

Sponsored