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Constantly adjusting heat

Gondul said:
They replied to this very thread on page 1...
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Oops, however that was still back in December, and we haven't heard anything since we discovered this issue in the logs.
 
Glad I'm not the only one experiencing issues here; my wife thinks I'm nuts since she likes it hotter than hell in anycase, but with the last few weeks being 85+ outside and therefore close to 100 in the cab in the midwest, it takes forever to cool down and I'm a sweaty mess by the time "MAX AC" has even made a dent. It genuinely barely blows stronger than my asthmatic ass, it's shameful.

I have a 2018 C Class as my second car and it's like being in the arctic in that within minutes, and on max the fan is so strong I can barely talk over it - in a good way! Couldn't be more different. It's honestly my biggest disappointment so far with the truck.
P.S. Yes, I also have dual controls.
 
In Texas and now the temp goes down slowly, wan to find the problem and solve it ASAP!
 
So today i decided to go take some readings with our FDA Certified IR thermometer to see what the truck would output manually set to MAX A/C. The truck was at Operating temperature 188, and the Outside temperature is 72. Keep in mind my truck has a SINGLE zone AC unit.

Here's the Dashboard

IMG_20200618_095149.jpg

and Here's the Vents

IMG_20200618_095114.jpg
IMG_20200618_095103.jpg
IMG_20200618_095055.jpg

Looks like from a hardware standpoint my output is pretty solid, and it's strictly software screwing me up.
 
g00fy said:
So today i decided to go take some readings with our FDA Certified IR thermometer to see what the truck would output manually set to MAX A/C. The truck was at Operating temperature 188, and the Outside temperature is 72. Keep in mind my truck has a SINGLE zone AC unit.
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When I use my digital IR thermometer on the A/C vents, it reads about 10 to 15 degrees lower than a HVAC thermometer probe. My HVAC buddy says they don't use IR thermometers for accurate readings; they only use thermometers with temperature probes.

Here is the first article I found that confirms IR thermometers should only be used to get a "general reading" for HVAC:


Infrared thermometer can give a general reading and are good in some cases. For example, a return air that is high up can get a quick general reading.

Infrared thermometer don’t work well with copper lines which scatters the infrared sensor.

Again manufactures may have some good ones out there (I haven’t tested them all) but in my experience infrared is only good to get generalized readings.
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g00fy said:
I think every time the truck is started, it monitors the cabin temperature continuously throughout the drive and adjusts the temperature accordingly. For example, I get in the truck, it's 58 degrees out, i have the temp set at 70, so the truck thinks the cabin temperature is 70, and it knows the outside temp is 58. So the truck blows luke warm air to maintain 70, but of course you start driving the suns out, and that luke warm air quickly makes it too warm in the truck, i change the temp to 68, now the truck thinks the cabin temperature has just dropped from 70 to 68, so it starts blowing MORE heat, so i turn the temp down to 64, truck thinks the cabin temperature just went from 68 to 64, the truck thinks is getting much colder, so it blows pretty much maximum heat at me.

I force the the temperature to LO, according to the logs, the truck is now seeing 0 degrees in the cabin, however some other piece of programming sees the LO setting and overrides the climate control logic and gives me cold air. I leave it for a minute, then slowly start working the temp back up, now i set the temp back to 64, so the truck sees the in cabin temperature spike from 0 to 64, and now gives me cool air because it sees the temperature is quickly rising, and continues to give me cool air up to 68 - 70 degrees depending on the outside temperature.

What i find super curious is the vent door control & fan speed seem to work correctly, if i turn the temperature setting down it changes the air flow to the dash vents as it's supposed to and it increases fan speed, but the temperature control gives me heat instead of cool air. And i've seen on the few hot days we've had so far, if i push the temperature UP, the vent control changes to foot vents and defroster and the fan speed goes up, but it continues to give me cool air.

It's almost like the Uconnect has control of the Vent Position and Fan speed, but the Climate module is doing it's own thing with the temperature based on the wonky data it's seeing from the false cabin sensor data.
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Hello.

I'm so glad I found this thread and your posts.
I have a 2019 Ram 2500 Longhorn Crew Cab Deisel. I bought it in Sept of 2019. Within one month I started realizing the HVAC system is not working correctly. Everything you say and others in here is absolutely correct.. I'd like to add a few bits as well.
Also, I'd just like to add. I'm a Aircraft Avionics Mechanic and and Electronic Tech. I'm not just blowing smoke out of my ears here. I know how stuff works.

I've had it to the dealer several times. I've taken vent temp readings as well as they also did.
So here is what I can add.
The problem exists in Auto or Manual mode with SYNC selected to on. I use Manual mode a lot more then Auto. It does not appear to be an issue in extreme temps like the hot summer or the extreme cold winters. Its very evident in spring and fall where the outside temps are intermediate and I'm using just vent air. Not AC or really hot temps selection.
When I get into the truck, start it , the engine has to warm up. If I happen to want coolish air like about 18 deg C, it wont give it to me. Instead it gives me 24 deg C air. Even if I turn down the temp to 16 deg C, it still gives me hot air.
It appears to settle down once the Eng temp gets to normal ops temp which is about 88 deg C. If I drive long enough cool air starts to come out of the vents. If I only do a short trip, the eng never gets to normal ops temp and I can never get the cabin temp correct. When I say vents, I mean the front facing vents. However, sometimes it will split the vent temp for a while before settleing down. 24 deg C out of drivers side and close to selected on pax side. In SYNC and in manual mode that should never happen. So I fight with the temps up and down until it feels like cooperating. The only way to pull down the temp is to select the LO setting. You are correct. LO overrides the variable temp selection and cool air starts to push out.

I've been playing with this a lot. Nothing works to work around it other then selecting LO. But then sometimes I freeze.
The dealer doesn't know how to fix it. They have been in touch with their internal engineers for direction. All they tried so far is that they changed all 4 of my duct temp sensors. Of course that did nothing.

I had a 2015 Ram 1500 Longhorn before this one with zero issues.

This is definitely a hardware software compatibility issue. I even approached CAMVAP as per my Warranty guide. But they won't help me because its a 2500 HD and its not applicable.. FCA is being arrogant about it and say you have to live with it..
The dealers hands are tied. They are given the tools by FCA corp to fix our trucks, but when they run the tests, of course it passes. That's because the test program is programmed to see the truck with the built in fault as normal. Even tho we know its not.
I'm about to send the CEO of FCA an email and push for support. My truck is now one year old and it irritates me every time I have to fight with it.
I can also say that because we all have to fight with trying to keep the cabin comfortable while trying, it's become a Health and Safety issue. Its a distraction while driving. We may run ourselves off the road, and get killed or kill someone else. I may also inform Transport Canada and state my case. This is ridiculous.

I'd love to hear back from any of you who have the scanners. We have to tel them how to fix it.

Thanks all
 
I am hoping TSB 24-001-20 may fix it. My truck is scheduled to get serviced next week. I will report back afterwards.
 
GLB1950 said:
If the Japanese decide to break into the HD market, (and they will eventually) the big 3 will get another rude awakening.
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Yea, Toyota could call it the One Tundra. I sent them an email a few years ago.
 
thestuarts said:
I am hoping TSB 24-001-20 may fix it. My truck is scheduled to get serviced next week. I will report back afterwards.
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Cseybert said:
Yea, Toyota could call it the One Tundra. I sent them an email a few years ago.
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Hi @thestuarts and @Cseybert, we are sorry to hear about the trouble that this may be causing you! Please see below for the attached TSB #24-001-20. To ensure this TSB applies, we would like to get you back into the dealer to have a qualified technician review the details of the TSB and specifics of your vehicle. Once reviewed, the technician can then perform the repair procedure that best matches the symptoms and diagnosis of your vehicle. Please send our team a private message for additional support throughout your dealer service if needed!

1611176844191.png


Kathryn
Ram Cares
 
Without reading this whole thread, it there a possibility this SB will fix the heat and the A/C issue?I believe I have both. Poor performing A/C and I'm constantly adjusting the heat in the winter.
 
99ls1tj said:
Without reading this whole thread, it there a possibility this SB will fix the heat and the A/C issue?I believe I have both. Poor performing A/C and I'm constantly adjusting the heat in the winter.
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Yes, the tsb should fix the issue. Have yet to hear of anyone on the forums having the repair done though. I assume most, like myself are waiting on parts.
 
RamCares said:
Hi @thestuarts and @Cseybert, we are sorry to hear about the trouble that this may be causing you! Please see below for the attached TSB #24-001-20. To ensure this TSB applies, we would like to get you back into the dealer to have a qualified technician review the details of the TSB and specifics of your vehicle. Once reviewed, the technician can then perform the repair procedure that best matches the symptoms and diagnosis of your vehicle. Please send our team a private message for additional support throughout your dealer service if needed!

Kathryn
Ram Cares
Click to expand...

@RamCares,

Thanks for reaching out to me. My local dealership performed the procedure in TSB 24-001-20. They started on Thursday, January 28th, and it took 3 working days to complete the work. They said it is a very complicated procedure that requires draining the engine coolant, removing the dashboard, center console, HVAC wiring, HVAC module, and two HVAC housings. They accidentally damaged the surface of my dashboard in the process. They ordered a replacement which will be installed at no cost, but it may take weeks for the replacement to arrive due to parts shortages.

The ambient temperature has been in the mid 40's here, so I can't really test the air conditioning until later in the year. The A/C does seem to be better than before the procedure. In particular, the middle driver's side vent is the same temperature as the other vents which wasn't the case before the repair procedure. In about 2 weeks, I will hook up AlfaOBD to see if the DRIVER SIDE TEMPERATURE SET POINT and CABIN TEMPERATURE SENSOR values are correct.

Here is a video I uploaded to YouTube that shows the problem I was having with the air conditioning before the procedure.

Here is a picture of the parts that were replaced during the procedure:

IMG_3147 (1).jpg

Here are the parts that were replaced:

hvac.JPG
 
Welp... I dropped our delivery truck 2019 5500 at my dealership 2 weeks ago because the parts manager called and told me ALL the parts were in for this TSB. I called and explained I needed to make an appointment for a TSB and made the appointment. I dropped the truck off Thursday 28th and again explained I was dropping off the truck for the TSB to fix the weak AC, the next morning I received a call from the dealership asking why the truck was there 1612988210509.png...

Anyway I hadn't heard anything since then, so i called Monday the 8th for an update. I was told they were waiting on parts and all the parts finally came in so they're just waiting for a tech to be free'd up to actually do the job... I get that we had a blizzard last week and i'm sure that really backed them up, but just tell me that, don't try and BS me... Hopefully they'll have the truck done by Friday and i'll be able to pull the new HVAC module out of the 5500 and put it in my 2500 to take some of my own logs to see if the updated HVAC module corrects messed up values in the system.
 
g00fy said:
@thestuarts very very interested to see if the set points and data are now correct in the system, please post asap!
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@g00fy,

Today I had time to test the set points. I am getting the same senor results as before the repair:
1. The Cabin temperature sensor value always mirrors the ATC Set-Point Right Temperature.
2. The ATC Set-Point Left Temperature is always blank.

I am using the latest version of AlfaOBD for Android. I tried using the latest version for the PC, but for some reason these sensor values are no longer available in the Climate Control data logging.

I did notice a new behavior with the latest AlfaOBD; it says I need to use a "MS-CAN BLUE Adapter" which I don't have.

Here are the possibilities, as I see them:
1. AlfaOBD needs the MS-CAN Blue adapter to properly read the sensors, but I don't have the adapter.
2. AlfaOBD doesn't really need the MS-CAN Blue adapter, but it is reading the wrong values from the CAN bus.
3. There is still a bug in the new version of the HVAC module (or somewhere else).


Here is a picture of the HVAC set to max low. Notice the Cabin temperature is reading 0 degrees Celsius (which it isn't), and the Left ATC Set-Point Temperature is blank.

Screenshot_20210225-134325_AlfaOBD.jpg

Here is a picture of the HVAC set to max high. Notice the Cabin temperature is reading 126 degrees Celsius (which it isn't), and the Left ATC Set-Point Temperature is blank.

Screenshot_20210225-134331_AlfaOBD.jpg

Here is AlfaOBD telling me I need the MS-CAN Blue adapter.

Screenshot_20210225-134349_AlfaOBD.jpg
 
thestuarts said:
@g00fy,

Today I had time to test the set points. I am getting the same senor results as before the repair:
1. The Cabin temperature sensor value always mirrors the ATC Set-Point Right Temperature.
2. The ATC Set-Point Left Temperature is always blank.

I am using the latest version of AlfaOBD for Android. I tried using the latest version for the PC, but for some reason these sensor values are no longer available in the Climate Control data logging.

I did notice a new behavior with the latest AlfaOBD; it says I need to use a "MS-CAN BLUE Adapter" which I don't have.

Here are the possibilities, as I see them:
1. AlfaOBD needs the MS-CAN Blue adapter to properly read the sensors, but I don't have the adapter.
2. AlfaOBD doesn't really need the MS-CAN Blue adapter, but it is reading the wrong values from the CAN bus.
3. There is still a bug in the new version of the HVAC module (or somewhere else).


Here is a picture of the HVAC set to max low. Notice the Cabin temperature is reading 0 degrees Celsius (which it isn't), and the Left ATC Set-Point Temperature is blank.

View attachment 12496

Here is a picture of the HVAC set to max high. Notice the Cabin temperature is reading 126 degrees Celsius (which it isn't), and the Left ATC Set-Point Temperature is blank.

View attachment 12497

Here is AlfaOBD telling me I need the MS-CAN Blue adapter.

View attachment 12498
Click to expand...

Well, data values aside, does the climate control actually behave better now? As long as it works better then who cares what the logs say lol.
 
g00fy said:
Well, data values aside, does the climate control actually behave better now? As long as it works better then who cares what the logs say lol.
Click to expand...

I have driven the truck very little since the repair, and I haven't needed the air conditioning.

I am going on a long road trip today. I will use Fireboard thermometers to log the temperature of all the vents to see if the temperature differential was resolved.
 
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