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Non digital to Digital Climate Control

8K views 6 replies 3 participants last post by  DrivenDaily 
#1 ·
Hello, I have the 2008 Malibu and wondering if anyone has ever, or if its even possible to change the temperature control in the car. Meaning changing the temperature control form a non digital to a digital. I see you can buy the head unit everywhere on the internet but dont know if the wiring is universal?? Any help much appreciated
 
#2 ·
Moved from General Discussion area...

... since this is about modifying your car.


Short answer: way too hard and expensive to "upgrade" from LT MCC to LTZ-style digital ACC. If I had it to do over again I'd order an LTZ with the MCC.

I don't like the automatic stuff. It's designed to take over every time you restart the car. (The whole car is so it's not unique in that respect.) I like plain and simple stuff, though I do do some mods no matter what. Turn switch on and it's on until it's turned off. I don't wanna have to keep telling my car that I'd like the fogs lights on, "please", like I have to keep begging it every time I start the engine. If I have the fogs switch set to "On" they should turn on when I start the car. Period. These reset to "Off" when the power dies. I know, it's a simple act of turning them on, but it's the principle, and the idea that the auto-dim mirror won't stay off, the AC won't stay off in auto mode even after pressing the AC button to disable it. Every time (and I mean every $%$^#$% time!!!) I start the car I have to go through all those settings again.

So, 4+ seconds to turn off the mirror, 1 second to turn on the fogs, 1 second to turn off the AC. Granted, not a lot of time, but I already had it set the way I wanted it and the $#$% car refuses to remember my settings.

But with simple switches, On is on and Off is off. It stays that way until I change it. Simple, efficient, less BCM programming, less frustration for the owner (who should be in charge of what goes on in the car, not the engineers!).

Stepping off milk box now...
 
#3 ·
I've seen this question posted before and the answer is always 'no' but it always seems that people are guessing. I have a 2012 and the 'manual' controls use electrical signals (not old-school push rods and linkages) to control the dampers, fans, and AC. Has anyone actually looked into the wiring harnesses?
 
#4 · (Edited)
Browsing through http://catalog.gmpartsdirect.co

here's what I gleaned so far, for a 2012 (you can research a 2008):
Automatic temperature controls, Ambient temp sensor $3.84 <-- edit apparently this is already installed in my car (1LT)
+bracket $5.02
+retainer pin $3.06
Automatic temperature controls, In-car sensor $5.18 X 2 (one for center duct, one for lower)
+Sensor retainer $4.34 x 2
Automatic temperature controls, Sunload sensor (aka Auto lamp sensor, W/climate control) $23.94 <--not sure if this is actually different from the light sensor used for auto dimming lights, assuming it is)
Blower motor, Resistor Malibu, w/ATC $106.03
Controls, Dash control unit Malibu, w/Auto Control $248.12
Center duct, W/climate control $8.38 <-- Edit through the dash vents I can see a square punch-out for the sensor retainer, a new center duct may not be needed (speculation)
Lower air duct, W/climate control $23.29 <--Edit it appears the in-car temp sensor is attached to this duct, a new center duct may not be needed (speculation)
Actuators on the Heater/AC Module Assembly would need to be swapped. I did not price them out, maybe about $200+

**The actuators on the Heater A/C module have different connectors, thus a harness swap is necessary.**
**no air conditioner components specified manual vs automatic climate control**

Edit: according to http://www.tonkinonlineparts.com/showAssembly.aspx?ukey_product=6141164&ukey_assembly=861617 the ambient temp sensor is in front of the radiator, and I can see it on my car (1LT) without auto climate controls.

Some more info here:
http://www.tonkinonlineparts.com/sh...line=8612&ukey_trimlevel=19635&modelYear=2012
 
#5 ·
What I think you seem to be missing is the actuators are programmed like the BPP (brake pedal position) sensor. The BCM has to know where the limits are for the actuators and needs to be programmed to learn that. Once known the HU (head unit) tells the BCM where you'd like the doors to be positioned. They aren't actuators that use a continuous flow of electricity to position them, which is what it looks like you're hoping they do. The BCM tells them where to move to, they move, and then the signal to move is complete. No electricity continually flowing.

If you want an ACC why not just get a control head that uses cables and modify it that way? The biggest issue is the temp control door. The rest of them could be on/off or maybe have a 1/2-way position to mix, but the current version mixes them more incrementally.

If you can get the parts, install them, and get it to work I'll be most interested! I'd like to "downgrade" mine to MCC.
 
#6 · (Edited)
Hi Driven. Bear in mid that I have a 2012 and other years may work differently than mine.

I'm not sure (simply because of a lack of evidence) that the dampers and feedback loop in the auto climate control system are any different than those in the manual system. In either system the control unit sends an electrical signal to position the dampers. In my 'manual' system I turn a dial that results in an electrical signal; there are no cables running from the back of the in-dash unit. It is possible that whatever signal being sent from the unit to the dampers is identical, and the difference is in the in-dash logic that generates that signal.

Your first paragraph basically discusses a feedback loop. My 'manual' system can select that air be blown to my feet, face, or the dash, or some 'in between' setting. This 'in between' setting suggests that whatever feedback necessary for positioning the dampers to an intermediate position already exists.

Adding cables to an automatic climate control system seems like a huge engineering task, I don't think I'll go that route. :)

I am curious about the different blower motor resistor for the automatic climate control system, and also the sun load sensor i.e. is that a replacement for the sunlight sensor on the dash used for the lighting system? Can anyone locate the sunload sensor (presuming it is separate from the light sensor) in their car? Edit: it appears the sunload sensor is located in the center of the dash and is a variation of the light sensor that switches the interior light brightness based on exterior light conditions. I can only find a part for the sunload sensor, i.e. I can not confirm that there is actually a different sensor for the automatic climate control system.
 
#7 ·
Instead of searching and bringing the thread and posts here as links I'll give you the privilege of searching and reading what you choose.

I have over 6000 posts as of this writing. I recall that some time ago a similar question was asked and basically the two systems don't merge. The MCC door motors might be the same or might not, but the rest of the system is not interchangeable.

Going to ACC from MCC might not be impossible but it's almost guaranteed to be impractical due to the amount of time spent, not to mention the cost. If you just gotta have ACC you should consider finding another vehicle with it just moving your license plates over. I don't wanna curb your enthusiasm but it just isn't something that has ever been attempted, and the discussion in the past has pretty much indicated it can't be done or isn't worth it.
 
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