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05 STS climate knob not adusting

2K views 14 replies 6 participants last post by  reneeg 
#1 ·
i can turn them both up and down and they either won't adjust the temp or will go the opposite way. I have tried slow, fast, etc.
can i pull the knobs and replace them? Everything works fine when i get the temp to the right setting.
Jeff
 
#2 ·
Funny you mention this as my driver side knob has been acting in this way too lately, mine at least works right if I just turn it slowly though. Not terribly concerned about it at the moment since it does work for the most part, interested to see what other members have to say about this issue though.
 
#5 ·
Programming is required if the module is new and may be required if it is used. There is a different software calibration depending on whether you have afterblow enabled or disabled. Afterblow is very useful in some climates. This is not just an option setting that can be changed using a Tech2, it requires use of the Service Programming System.
 
#4 ·
Kinda figured that was going to be the conclusion. You can find used HVAC units on eBay all day long for good prices....Back when I owned my 2001 STS my HVAC unit completely died, wouldn't come on at all. I got raped for $400 for a replacement, now I can find units on eBay for less than $100, pisses me off when I think about it, should've just done it myself.
 
#6 ·
ddalder said:
Programming is required if the module is new and may be required if it is used. There is a different software calibration depending on whether you have afterblow enabled or disabled. Afterblow is very useful in some climates. This is not just an option setting that can be changed using a Tech2, it requires use of the Service Programming System.
But using one that's set either way will not disallow function of the system which is why I stated but used its not required. Not to mention for one to have afterblow enabled would be VERY rare. Never said it didn't have programming. I should of been more clear.

Afterblow is a feature that dries the evaporator core by operating the blower motor after the engine is turned off. This reduces the amount of microbial growth that can create undesirable odors. The vehicle does not come equipped with the afterblow feature turned on. If the afterblow feature is required due to an odor concern, it must be turned on by reprogramming the HVAC control module, refer to Service Programming System (SPS) in Programming and Setup.

After the HVAC control module has been programmed for afterblow, the following conditions must be met for afterblow to operate:
•The engine has been turned off for at least 30 minutes.
•The ambient air temperature is at least 21°C (70°F).
•The A/C compressor operated for more than 2 minutes.
•The system voltage is at least 12 volts.

Once the above conditions have been met, the following sequence of events will occur:
• The blower motor will run for 20 seconds.
• The blower motor will be off for 10 minutes.
• The blower motor will run for and additional 20 seconds.
 
#7 ·
But using one that's set either way will not disallow function of the system which is why I stated but used its not required.
True enough, I only mention this because depending on where the OP resides, it may be helpful to ensure it is set correctly. I've already had to spend $100+ to have and anti-bacterial agent introduced to my AC system for a pungent smell because afterblow wasn't enabled on my car. I honestly don't know why this isn't set 'On' by default.
 
#8 ·
Im assuming there has to be a massive electrical load on the system to keep the car "awake" that long. The usual sleep time is 10 minutes, for the module to function after that means there has to be a draw on it. Not to mention if someone stuck around long enough to have the system activate then they would assume something is wrong as opposed to a normal function of the system.

Isn't the setting for the air quality sensor stored in the HVAC module too?
 
#9 ·
I would have to look back to find out what the time parameter is. I know that the ambient temperature must be within a certain range and the AC must have been active in the last ignition cycle for a minimum amount of time (the exact numbers escape me). I thought the sleep time was more toward the 15-20 minute time frame but I'm not positive. As I recall, afterblow, if parameters are met, comes on within the time frame allotted before sleep mode. I'll review the tech info again later and post a correction if I'm too far off.

Yes, the sensitivity settings for the air quality sensor are stored in the HVAC module. The HVAC module will sense whether the sensor is connected or not. I don't recall seeing anywhere that this had to be turned on/off depending on presence.
 
#10 ·
Already posted them above :thumbsup:


After the HVAC control module has been programmed for afterblow, the following conditions must be met for afterblow to operate:
•The engine has been turned off for at least 30 minutes.
•The ambient air temperature is at least 21°C (70°F).
•The A/C compressor operated for more than 2 minutes.
•The system voltage is at least 12 volts.

Once the above conditions have been met, the following sequence of events will occur:
• The blower motor will run for 20 seconds.
• The blower motor will be off for 10 minutes.
• The blower motor will run for and additional 20 seconds.


So if all are met the car is drawing power for an additional 40 minutes 40 seconds after shut off.
 
#13 ·
Cleaning did help a little but it started to come back again. That's when I looked further to find that the dealership didn't bother to enable afterblow even though this problem was brought to their attention. On top of it all, they charged me for this service even though the car was still under base warranty at the time. I explained that when my parents Pontiac minivan was under warranty they weren't charged. They gave me some excuse that it may be based on geographical location. What geographical location??? We live in the same city!!! Sorry, rant over. One more reason I'll never, ever take my car back to Calgary Motor Products.

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If you want to have this done, tell them that the technician needs to reprogram the HVAC module using SPS with the calibration for afterblow enabled (or ask to speak with the technician who will be doing the work). This should give the tech enough of a clue what to do, assuming the advisor actually passes it along.
 
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