No power at HVAC Control Panel?

Hello, thanks for reposting the question. If all this happened after the battery replacement and everything was fine before. I think I know what happened. On the Negative battery terminal, you have one of these current sensors, correct? This current sensor communicates on the Lin Bus data network. And with the codes you have it appears the Lin Bus network is either completely down or shorted out. It is a 0v to 7volt signal, but if all you did was change the battery, these little sensors are extremely sensitive to how much they are tightened down. As well as any corrosion there might have been on the negative post. The Humidity sensor is on the Lin Bus, this vehicle also has something called a "Private Bus". I have never heard of this one before to be honest. But the Heater control module is on it, and it looks like this Private network is communicated from the PCM which acts as a Gateway for certain modules. PCM talks on the can bus to other main modules and then out to smaller less important modules on slower networks. It also looks like the Body Control module is a gateway as well for 2 different Lin Bus networks, the Alternator is also on the Lin. I would try unplugging the Battery Current sensor harness plug, it should be a 2-wire plug on the sensor. Erase all codes, leave the Current sensor unplugged and rescan for codes. See what comes back. It might be that the current sensor is broken and pulling the network to ground (0volts) I will post the proper way to install a new sensor and the negative battery cable. If you removed that small nut on the negative cable it will break. You'll have to follow the instructions for this, they're pretty specific.
And what module did you hit with the Battery on installation?

Diagrams 2 to 7 are the removal process for the sensor. 8 to 13 are the Installation process for a new sensor. The M6 captive nut is not removeable. It will break if you try to remove it. It is only to be loosened enough to get the new sensor on the Battery post. You will need to clear all the codes as well; some systems may stay shut down if there are codes stored. Also noticed in the last installation step there is a torque spec of 16 Nm. 16 Newton meters is about 141 Inch lbs. It's barely anything. You can use an Inch lbs torque wrench for this.
The M6 nut torque spec is only 7mn (about 62 Inch lbs) that is the nut that clamps on to the Battery post. That's on page 1 of the Installation page.
I would check this Fuse F52 5amp, it runs to Battery sensor. I will update this with any additional info I come across.
If the Fuse F52 is blown, don't just replace it, if it's blown then there is most likely a short to ground through the Battery Current sensor.

I could be, it's actually a very important sensor, it relates current flow to and from the battery and also battery temperature to the ECM for specific charging, its supposed to be a smart charging system, but like all advancing technology it breaks too.
Sorry I just saw the rest of your post. The fact that you have a code for lost comms with IBS means the sensor most likely got damaged during the battery change over. You have to follow the unhooking of the cables and reattaching them in the sequence that is stated in the service info. The reason I think they're so specific with that is there is 12v positive running to that sensor as well as it acting as a Ground for the battery. Of the 2-wire connector, 1 is the Lin bus and the other is 12volt positive to power the sensor. So, it's like having an amp clamp on the negative battery cable. Hopefully it didn't short out and somehow damage the BCM in any way. What are the 2 Front Gateway codes you are getting with the IBS code?

That took care of all the codes. What I don't like about these sensors is the rust that builds up on them. That to me says that they're not built well. I've been trying to figure out why you would lose comms with the HVAC module and not anything else on that network because of the current sensor. It's a strange one, it's difficult to find definitive answers sometimes when it comes to network issues. But I would think it would pull the entire network down. This is the Lin bus that the IBS is on, and I can see the humidity sensor shutdown the HVAC module because I've seen that before, but maybe you just don't have these other modules in your vehicle. I'm not 100 percent sure on that one. The HVAC module is not on this network, but for whatever reason if the humidity sensor is not working weird stuff happens. And actually, after looking at the OEM diagrams, these aftermarket diagrams below are incorrect with the wiring labels.

It doesn't appear to be a Ground fault, it has something to do with that particular Lin Bus. This is almost the exact same situation with the other Dodge except with him we took the long route in the diagnoses. His Lin Bus connection was bad at another point also. And it was actually just a pin fitment issue in the bulk connector. The HVAC module is not on the can bus data network (high speed data), it is on a slower low speed type network. It really depends how each system is wired. But those little current sensors are really important. On most modern vehicles now you need to use a scan tool and do a Battery Reset so the ECM knows a new battery was installed. But everyday is learning experience in this industry.

It depends, there are a couple Lin Bus networks in this vehicle, and it doesn't have to be a total loss of the network, the information bus diagrams are shown with modules that your vehicle might not even have. They show the design of that entire data bus with every configuration it can come with and have some little labels here and there that say "Diesel" or "Except Diesel" if a section is not included. They are very in depth. But yes, if the negative terminal was not completely seated fully or just the nut or bolt for the current sensor or the connector pins internally were not fully seated, the sensor wouldn't read correctly. As you can see it's a cheap little plastic sensor, with a temperature sensor also built in, and plastic is dramatically affected by temperature. Pin fitment issues can be some of the most difficult issues to deal with. It can appear that a module has failed, but you back probe a connector and read what is supposed to be there for a correct voltage, but it's not actually making it into the module because of the connector. And after years of these connectors heating up and cooling down every drive cycle, eventually connectors will loosen up. Thats why on the other Dodge, all he had to do was reconnect the bulk connector and the issue was gone. We do pin drag tests on connectors to find loose pins.
And using a capable scantool you should be able to see the live data from the current sensor. It will read what the amperage is while the battery is being charged back up and being discharged on a cranking event. You can also use an oscilloscope to monitor the Lin bus signal on that one wire, since it's only a 1 wire network. It's a 0v to 12volt square wave signal that you can only see with a scope zoomed in on because of the speed. This is a Lin bus signal at 1milli second per division.
Sorry for the long post.