New Caprice - Discussion forums

Has anybody attempted to put a digital hvac control from simalar year impala or malibu to replace using it threw the radio in hopes of installing an aftermarket radio? Also does anybody have a wiring diagram for the hvac controls and radio?

HVAC controls are all ran through the Low speed Lan Data Bus to the HVAC module and BCM. THere are only about 14 wires going into the Radio plug and 8 of those are speaker wires. so basically 6 wires to run all the functions of the radio and HVAC. That means the Impala controls would have to be compatible with the same GM Lan system. GM has made strides to make things common between cars for cost cutting measures but I have not seen a common principle between GM NA and Holden thinking.

Could it be done, maybe, but you better get to learning the programming code behind it and start experimenting.

THe G8 guys have a aftermarket digital screen that controls HVAC functions. I would say you have a better chance of getting that to work although it is also designed for a HVAC system a generation behind the PPV's . Think it is called G8 Designs. Video here:

https://www.youtube.com/watch?v=B0psWaM6iwM" onclick="window.open(this.href);return false;

You see that says for "series 1" style cars compatible. PPV's are Series 2

Another vid on the HVAC Setup:
https://www.youtube.com/watch?v=ORNgnVCeDTI" onclick="window.open(this.href);return false;

From G8 Designs FB page:
Do you know how many PPV owners and Aussies message us monthly begging for us to make a kit to rid them of that IQ nightmare? Bunches! And we hope to do that soon to help them out, but we're not there yet.

What is an example of a car that has a separate digital HVAC controller? I would guess there is a chance that they output the correct messages or could be translated.

I saw that some Subarus have a case where a non-integrated HVAC controller was available just like this.

It is my understanding that a lot of the GMLan messages have been sniffed out and listed here. There is a lot of climate control info, I do believe these are from the G8 era Holden and there must be some reason that they have not been able to update their controller to the Holden IQ system. I don't know what the differences are between different GM models.

https://docs.google.com/spreadsheets/d/ ... dit#gid=23" onclick="window.open(this.href);return false;

One thing I don't really understand is why the new aftermarket radios that can control the HVAC on some models supposedly don't work. Is the Holden IQ really that unique? It seems like this is a common problem for all cars that have integrated HVAC and radios.

It does seem like there must be other people that may have looked into this, but I haven't come across it so far. I did sort of look a bit, but Google isn't what it used to be exactly.

It is hard to tell without actually seeing these modules, but it looks like they fall into at least two major categories. The Impala appears to have four separate plugs with many connections in each plug. The Malibu and the Cruze belong to the other category and appear to have a single plug with maybe 4-6 connectors. The type with only a few connectors would probably be the only possible candidate. There are a few touch screen options for the G8 era cars. Those require power, ground and the signal wire to the can bus. I think it is a good chance they operate similarly. Maybe the extra pins are just for a light or something.

I think it would be possible to get one of these controller and bench test it in order to sniff the signals that the controller sends. I also think it would be possible to sniff these signal through the OBD port without taking anything apart. There are lots of tutorials on this, but you need a code scanner that can read the SWLAN signals. Not all code readers can read those. The OBDLink MX supposedly can and is the cheapest off the shelf one I have come across. It would be pretty nice if the signals were the same so you wouldn't need to translate anything. Perhaps there is already a GMLAN bible like document for the Malibu or Cruze.

This just occurred to me, but I guess it should have been obvious.

The 2014+ Caprice HVAC controller is also a candidate as far as the signals go. Maybe there is someone out there with a code reader and a 2014+ that could test a few button presses to see if they match the GMLan Bible codes.

wx39c1 wrote:This just occurred to me, but I guess it should have been obvious.

The 2014+ Caprice HVAC controller is also a candidate as far as the signals go. Maybe there is someone out there with a code reader and a 2014+ that could test a few button presses to see if they match the GMLan Bible codes.

Not going to happen 2014+ is Global A completely different architecture. Also... sad to say about 40% of the data in that "bible" is wrong

Are the 2011-2013 Caprice HVAC codes somewhat similar to the codes in the GMLan bible? Couldn't a corrected GMLan bible be made?

What is the main issue that is holding back G8 Designs from being able to make a digital one? What is needed besides just playing the correct messages? They seem to indicate that it is possible.

It does appear that all of the controllers that have the 6 pin or so outputs do belong to the Global A architecture. That makes it easier to find candidates that look nice at least. Being Global A appears to mean that are encoded. Do these need a code in order to power up, or can power up on their own and then just send encoded messages? If it can power up on its own, then there is some hope of making a translator.

On a side note, it does appear that there are aftermarket HVAC controllers and radio options for Global A based vehicles. That would make me think that the HVAC button takeouts for these would be somewhat readily available.

Has anyone looked inside one of these controllers from a Global A car?

Looking toward trying to put one of these controllers from a 2011 tahoe seems to have all the same controlls minus being able to set temp for rear defrost