Tesla Radio PX6 and Air Conditioning

[knightjp]

While driving the other day, the AC compressor suddenly got jammed. Had to get it replaced. After replacing the part, my mechanic said that the reason for the failure was that compressor and the fan motor were getting overworked by the head unit. He said that once the truck cabin cools down, it is supposed compressor and blower is supposed to slow down. It's not. He tested it.
Any ideas? Anyone with a 4th Gen Ram 1500 and one of these radios have this issue?

 

[chopperman1]

Compressor is either on or off, it is not variable. If you previously had an "auto" setting that controls fan speed. Not all trucks have "auto". Your mechanic is talking out his backside.

 

[knightjp]

Compressor is either on or off, it is not variable. If you previously had an "auto" setting that controls fan speed. Not all trucks have "auto". Your mechanic is talking out his backside.

I think that is what he meant. I suppose that it is my fault for the poor choice of words.
He is a pretty good mechanic and does the air conditioning for high end cars like Mercedes and BMWs. So I'm pretty confident in his abilities.
When the temperature reaches what it needs to be, the compressor is supposed to shut off, but that doesn't seem to be happening.
As for the auto setting, I'm not sure about it. This is a picture of my stock interior.


I do recall that some had put the MAX A/C on in the unit. Maybe that is what is causing the issue. Right now since it is a public holiday I cannot check on it right now till Monday. I will check and revert back.

 

[knightjp]

OK.. There is an update.. This is the fault code.

According to the mechanic the airconditioning system is not able to talk to the head unit / AC system and therefore the system is working overtime when in reality, the compressor needs to be able to cut off periodically and its not.

This is what I can understand.. So if anyone has experience with this and one of these headunits, do let me know.

 

[knightjp]

OK.. I didn't get much of a reply on here and not sure what exactly caused it. This is the way that I understand what happened.
When I purchased the unit, I was told that I needed to specify the AC I had in my truck by showing them a picture of my dash. At the back of the unit a canbus module is connected; which is supposed to talk to the vehicle; especially the HVAC system.
Just before the AC compressor gave way, I noticed that my steering controls for the unit's radio were not working. For that week, we were having some really hot days where the temperatures were reaching well close to +49.C with high humidity levels as well; making if feel even hotter.
My assumption is that my aircondition was set to the highest obviously and I'm guessing the canbus module that was given with unit, overheated and stopped talking to the truck. This was why my radio controls were not working. Hence the cabin sensor failed to notice that the cabin was cool and didn't cut off the compressor. My in-dash blower fan was going on full blast and my compressor was working continuously. The mechanic said that when cleaning and clear the AC pipes, he found ice. This was not good and caused my compressor to burn out. Now I had to replace the compressor.
Now after it all, the mechanic now added a second aftermarket cabin sensor/module which won't lose connection with the aftermarket headunit. Now that the codes have been cleared, the unit is talking to both sensors I believe and if one fails, the other will keep it going so I won't face this issue again.
We'll see how it goes. I'm going to go to my mechanic after a couple of days and ask him to show me what exactly he did and I'll video it. So maybe if anyone else has this issue, we can sort it out.

I do suspect that maybe the original cabin temp sensor module might have failed as well. But then the fault code was suggesting that it wasn't able to talk to the center stack.
Will keep this updated so that it could help others.

 

[crash68]

The mechanic said that when cleaning and clear the AC pipes, he found ice. This was not good and caused my compressor to burn out. Now I had to replace the compressor.

If your mechanic found ice inside the AC piping, this is what caused your failure and not anything to do with the head unit. Refrigeration systems don't like moisture, if there was ice that means there was water in there. I'm guessing it was either from a previous shoddy repair or from someone topping off the refrigerant charge incorrectly. Hopefully your mechanic did a good job getting any moisture out of the system or you'll have more problems.
As for the aftermarket radio causing the problem, I doubt it. The radio just reads the HVAC information from the BCM and HVAC modules and is the graphical human interface. The AC system can also run 24/7 on MAX Cool without any issues, it's the conditions it runs in like high temperatures or mechanical failures that can cause problems.

 

[knightjp]

@crash68 Thanks for the reply. Considering I bought this truck second hand, I'm guessing that maybe that was the case. Not sure though. However after he cleared everything and he replaced the compressor. He noticed that the compressor was not cutting off and stuff like it normally should. He plugged in the diagnostic scanner and it showed the fault codes I posted above. Hence why he suspected the canbus module connected with the head unit.
Noting that I could not control the radio using my steering controls just before the compressor went, I'm guessing the canbus module of the head unit was not working correctly.

It is interesting to note that after he fixed everything and added the secondary aftermarket sensor, the radio controls are working fine again. So I'm a little confused. I will be going back, meeting him and have him explain what he did and record it. This will probably give a better picture. Maybe I'm not describing the issue correctly.

 

[crash68]

He noticed that the compressor was not cutting off and stuff like it normally should.

Does your truck have the single zone ATC mod done? (Do you have the option for Auto Climate control but only one pair of warmer/cooler buttons?)
If this mod was done and it can't read the windshield humidity/dewpoint sensor the compressor will run continuously.

Some aftermarket head units don't work well with this mod as it's not a factory available option.

 

[knightjp]

Does your truck have the single zone ATC mod done? (Do you have the option for Auto Climate control but only one pair of warmer/cooler buttons?)
If this mod was done and it can't read the windshield humidity/dewpoint sensor the compressor will run continuously.

Some aftermarket head units don't work well with this mod as it's not a factory available option.

I believe it is single zone.

This is what it looked like stock.

 

[crash68]

I believe it is single zone.

Your pic is a little blurry to make out details.
If you have an "Auto" button on the HVAC screen and possibly in the center of the fan speed knob then you have the ATC mod.
If you're center bezel has two sets of warmer/cooler buttons and your HVAC bezel looks similar to this:

That's the factory dual zone, there will also be two temperature slider on the HVAC page along with temperature settings (at the top of the screen).

 

[knightjp]

@crash68 I don't have a dual zone. I just have one set of temp sliders.

 

[SitKneelBend]

I believe it is single zone.
View attachment 497899
This is what it looked like stock.

Looks like single to me...