In July I saw a couple active codes listed below along with inconsistent A/C performance.

P1009 - Humidity Sensor Module (BCM)
U0422 - implausible data received from BCM (HVAC module)

I replaced the humidity sensor with Dorman p/n 926-369 and I thought all was well up until now. It's probably been like this for a while, but my wife normally drives the van and she didn't notice it. I drove it the past couple days and the weather's been unusually warm. It was very obvious that the A/C was running all the time regardless of what the HVAC settings were. The A/C should normally only run in auto mode, if defrost mode is selected, or if the A/C button is lit up blue.

I fired up the scan tool and sure enough, the "Customer Has Selected AC" datastream shows "True" for all HVAC settings except when it's turned completely off. At first I thought it was an issue with the HVAC module or the control panel. However, after looking into it a bit more I'm convinced the Dorman humidity sensor is to blame. I've read that 2014+ RAM trucks have a similar issue and the non-OEM humidity sensors just don't work right.

I now see these two active codes:

U1190 - Lost Communication With Humidity Sensor (BCM)
U0422 - implausible data received from BCM (HVAC module).

This actually makes sense because the humidity sensor communicates directly with the BCM first. The BCM then relays the data to the HVAC module. I'm going to buy the Mopar part (68440808AA) and do some testing before I put it in just to be sure the wiring is good. I'll post back when I have an update.

Thanks so much for the detailed write up!
I never thought to check for codes for this frequent and annoying, but intermittent problem. And even then, I tried using Torque Pro with my bluetooth obd2 scanner and it didn't find any codes.

It wasn't until I tried the CarScanner android app that it found the P1009 code so now I'm pretty sure this is the solution. This has been bugging me for almost a year but it's not until recently the weather has been cooler and having the A/C come on these days is not desirable!

I fired up the scan tool and sure enough, the "Customer Has Selected AC" datastream shows "True" for all HVAC settings except when it's turned completely off.

BTW - which scan tool are you using to see this?

 

Thanks so much for the detailed write up!
I never thought to check for codes for this frequent and annoying, but intermittent problem. And even then, I tried using Torque Pro with my bluetooth obd2 scanner and it didn't find any codes.

It wasn't until I tried the CarScanner android app that it found the P1009 code so now I'm pretty sure this is the solution. This has been bugging me for almost a year but it's not until recently the weather has been cooler and having the A/C come on these days is not desirable!



BTW - which scan tool are you using to see this?

I feel your pain because the air coming out seems to be much colder than it should be regardless of the HVAC/temperature setting.

I'm using a Launch X431 CRP919XBT Elite scan tool that I purchased during the Amazon Prime sale a few months ago. I have some minor complaints, but it works good for the most part. I know I can use the SGW bypass cable, but I have an FCA AutoAuth subscription ($50/yr) so I don't have to mess with it.

I went to pick up the sensor from the dealership Saturday, and of course they just sold the one they had in stock Friday. My wife just hit a deer with our van last weekend so it will be a few weeks before I get a chance to put it in anyways. I'm very confident the Mopar part will fix this problem. I will definitely post a follow-up at some point after I get it installed. I was pleasantly surprised to hear the body shop say all the parts they needed were readily available, so hopefully it won't take too long for them to fix it.

 

The new part (68440808AA ) arrived but I took one last check of the problem it's not happening for the past few days. Also, the P1009 code is now inactive.

I figured this would happen as the issue has been intermittent for me. It's also why I never bothered taking it to the dealer to fix.

Anyway, since there's no rush at the moment I'll keep monitoring until it resurfaces and figure out the fix procedure at that time.

 

We got the van back from the body shop and I installed the new humidity sensor today. I tried to check the voltage on the 3 wires in the connector first, but my probes are far too big. I looked for a small paper clip to hack up and insert into the terminals, but I couldn't find one so I rolled the dice and installed the new sensor anyways. Even with my employee discount it still cost almost $87 from the dealership. Anyways, I've driven it a couple times and so far so good. The U0422 and U1190 codes haven't returned after clearing them, and the A/C is definitely working as it should now. I also confirmed the "Customer Has Selected AC" datastream toggles true/false like it should instead of staying true all the time.

I don't have the original sensor I removed before installing the Dorman part, but I recall that those two looked nearly identical. The new sensor looks different than the Dorman part I removed (see pictures below). The Dorman 926-369 is on the left, and Mopar 68440808AA is on the right in both pictures.

I hope this helps somebody. Again, the main symptom with the Dorman part installed was that the A/C was basically running all the time causing the HVAC system to output cooler air than it should regardless of the temp/mode settings unless the HVAC system was turned completely off.

 

Thanks for all your help @freddief73!
With your advice, I finally got the cover off with a 90 degree pick (though I snapped a small piece of one of the clips somehow but it doesn't seem to matter) and replaced the humidity sensor and all has been well for the past day.

The P1009 code is inactive, hopefully permanently this time.

I wish I had taken a video as none of the steps on the Pacifica was as easy as Youtube videos for other CDJR cars would have suggested.

But all is well now and I'm glad to put this problem behind me.

 

Where is this humidity sensor found?

 

It's against the windshield just to the right of the rearview mirror.