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2006 STS 3.6L
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27 Posts
Discussion Starter #1
The driver's side heater control knob has steadily become more unruly during the last 6 to 8 months. Whether turned clockwise or counterclockwise, the tendency is for the setting to stay the same or change to a lower value. I've tried to "exercise" it vigorously, and I've tried turning it while exerting a "pull" or "push" - with lackluster results using these efforts. With the current cold snap it's functionality has reached a new low and my wife is (justifiably) concerned that the driver's side heat setting is going to be stuck or only be able to be turned lower.

I've searched for threads to no avail and am tempted to use contact cleaner in some way before jumping in to full "HVAC CONTROL MODULE REPLACEMENT". It seems like a little much to remove the ashtray, radio, HVAC control module, replace the unit, reinstall the radio and ashtray (ashtray being notoriously fragile as well) and then pay(?) for programming and setup information all for a "crunchy" potentiometer.

The vehicle has this option: "KB6 Seats, heated and cooled driver and front passenger". New units are $290 to $300 whereas used can be had for $30 to $100. Obviously, being wintertime and all kind of makes me want to wait a few months as well. Any thoughts or advice are much appreciated.
 

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1989 Fleetwood FWD / 2000 ETC / 2000 STS / 2006 STS V-8 1SF RWD
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476 Posts
Hello...


Ideally the system operates as 'set it and forget it'…much like the HVAC thermostat in your home.
It’s designed to keep the cabin at the desired temperature…not blow air of a set temperature.
Select AUTO with your preferred temperature and never touch the button again.
But sometimes I want more control.

My temperature knob sometimes doesn't easily adjust.
I was going to try some compressed air.
In the meantime, I can change the temperature using a voice command.
This method is sometimes hit and miss.
Press the Voice Command button and say:

HEAT...SET TEMPERATURE 75

There are variants as noted in the photo below.
YMMV

temp voice command.JPG
 

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2009 STS 1SG, 2013 SRX
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225 Posts
Programming is not required for the HVAC unit. It is a simple and fast fix, albeit costly.

Try to find one at a junkyard.
 

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Registered
2006 STS4 V6
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436 Posts
Hello...


Ideally the system operates as 'set it and forget it'…much like the HVAC thermostat in your home.
It’s designed to keep the cabin at the desired temperature…not blow air of a set temperature.
Select AUTO with your preferred temperature and never touch the button again.
But sometimes I want more control.

My temperature knob sometimes doesn't easily adjust.
I was going to try some compressed air.
In the meantime, I can change the temperature using a voice command.
This method is sometimes hit and miss.
Press the Voice Command button and say:

HEAT...SET TEMPERATURE 75

There are variants as noted in the photo below.
YMMV

View attachment 544196
Is the VR only for the navigation equipped STS's?
 

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Registered
1989 Fleetwood FWD / 2000 ETC / 2000 STS / 2006 STS V-8 1SF RWD
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476 Posts
Hello...

Yes, it appears so.
From the Nav Manual:

The navigation system’s voice recognition allows for
hands-free operation of navigation, phone, audio system,
climate controls, windows, OnStar®, and memory
features.

To use the voice recognition system, the map DVD
must be loaded.

To use voice recognition, do the following:
1. Press the talk symbol
steering wheel control
and release it when
you hear a beep.
 

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2006 STS 3.6L
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27 Posts
Discussion Starter #8
I can change the temperature using a voice command.
Press the Voice Command button and say:

HEAT...SET TEMPERATURE 75

There are variants as noted in the photo below.
YMMV

View attachment 544196
I believe the following commands SHOULD be available:

1) Heater/heat, heater/heat turn on/off
2) AC/air conditioning, AC/air conditioning turn on/off
3) Heater/heat/AC/air conditioning [set] fan high
4) heater/heat/AC/air conditioning [set] fan low
5) Heater/heat/AC/air conditioning [set] temperature (number)
6) heater/heat/AC/air conditioning turn defrost/defog on/off
7) Heater/heat/AC/air conditioning turn front defrost/defog on/off
8) heater/heat/AC/air conditioning turn rear defrost/defog on/off
9) Heater/heat/AC/air conditioning help: This command
instructs the system to assist with climate control
commands. Help commands will be displayed on the
map screen when the vehicle is stopped

LINK

When using command #5, however, the system returns "COMMAND NOT RECOGNIZED".
Furthermore, when using command #9, the system displays every command in the list EXCEPT command #5. W.T.F?
 

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1989 Fleetwood FWD / 2000 ETC / 2000 STS / 2006 STS V-8 1SF RWD
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476 Posts
When using command #5, however, the system returns "COMMAND NOT RECOGNIZED".
Furthermore, when using command #9, the system displays every command in the list EXCEPT command #5. W.T.F?
I know I have used this with positive results...but maybe it was when I set the language to Spanish.
The VR seems to perform better with a phonetic language.
I'll have to try it again in both English and Spanish.
 

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2006 STS (1SG LH2 M22 JE5 FE3 F55 Q12 T43 K59 UV6 TT6 TQ5)
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62 Posts
I have the same temperature setting knob issue. I don't wanna use Voice Command. Does anybody have any tips for getting the knob to work better? Everything else on my car works great (except for a coolant temperature gauge issue I'm having after just flushing the coolant, described here), and I'd like to get the knob working just as well.
 

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Premium Member
2006 STS V8 AWD, '95 Ford Ranger
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29,072 Posts
The temp control knob is not a potentiometer, it's a pulse generator. Turn it CW and it generates pulses that bump the setting up. Turn it CCW and it generates pulses that bump the temperature down. It has no physical stops. It will turn around and around. If you turn it too fast the pulses are ignored because they come too close together. I'd be trying contact cleaner if mine didn't work.
 

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2006 STS (1SG LH2 M22 JE5 FE3 F55 Q12 T43 K59 UV6 TT6 TQ5)
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62 Posts
The temp control knob is not a potentiometer, it's a pulse generator. Turn it CW and it generates pulses that bump the setting up. Turn it CCW and it generates pulses that bump the temperature down. It has no physical stops. It will turn around and around. If you turn it too fast the pulses are ignored because they come too close together. I'd be trying contact cleaner if mine didn't work.
This is what I’ll try on a replacement unit I pulled out of an ‘05 STS at my local Pick-N-Pull yesterday for $22...but, wait for it, behaves the same way! So into its guts I’ll dig in the next few days and see if I can come up with a fix for my original unit.
 

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2006 STS 3.6L
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27 Posts
Discussion Starter #14
(I)… am tempted to use contact cleaner in some way…
I'd be trying contact cleaner if mine didn't work.
So treat it as a regular analog control? For example, pull the knob off, apply a small amount of contact cleaner and work it into the control and then wait 30 mins before testing?

Here's an excerpt that I found where they are cleaning out a pulse generator volume control (LINK)...

"...I went through the same procedure to fix a volume control problem on my VSX-1015. Knowing the volume control could not be a good old fashioned "potentiometer" (analog resistor), but rather a pulse generator, I was curious what could possibly go wrong inside it. So I de-soldered the thing (need solder suction pump), and opened it by gently plying the 4 lips holding it together. The problem was... grease, having seeped in from the axis (probably injected to generate the heavy duty quality feeling when turning the knob). So I removed the grease using cotton swabs first, then the finest paintbrush I could find from my kid, and then cleaned the contacts and copper tracks with isopropyl alcohol - ALL VERY CAREFULLY. After having put everything back together - works like a charm now :)

bobcuyt - 09/18/2016

I think I lost some of the heavy duty feeling using Deoxit to fix the problem but I'd rather lose the heavy duty feel for a more gentle knob feeling where I know the problem probably isn't coming back (I said temporary because I don't know how the unit was treated or if the unit was damaged by pushing it hard, which damaged the potentiometer.) Yeah it's now prone to slipping when you want 50 rather then 65 but I would take that over a repeat of the issue.

Nick - 09/18/2016

So into its guts I’ll dig in the next few days and see if I can come up with a fix for my original unit.
I'd be interested to see if the control knob pulls right off
 

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2005 STS 1SF white
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24 Posts
I have the same issue with my car, I was thinking the same thing about the contact cleaner. Let us know what you find.
 

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08 STS-4 N* 1SG, 08 DTS Luxury II, 04 Bonneville GXP N*
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3,215 Posts
Programming is not required for the HVAC unit. It is a simple and fast fix, albeit costly.

Try to find one at a junkyard.
This is not necessarily true. These are programmed either with or without afterblow enabled. Unlike some other GM vehicles that have a setting easily toggled with a Tech2, a new calibration must be downloaded into these modules to change this. I already paid to access SPS so I could enable it and try to alleviate the smell from the AC. If I replaced mine, I would want to ensure it was enabled.
 

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2006 STS (1SG LH2 M22 JE5 FE3 F55 Q12 T43 K59 UV6 TT6 TQ5)
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62 Posts
OK...got mine working great! Here's a brief scoop (I'll try to do a more complete write-up with pics as soon as I have time)...

The knobs will pull off. Be careful to use something that will grip firmly without marring the rubber-like knob coating, because the sleeve inside the knob grips the pulse generator shaft tightly. (At first I couldn't just pull off my knobs, so I did a full removal and disassembly of the entire HVAC control unit...then I figured out that the knobs could pull off after my disassembling.)

Because the pulse generators (which the knobs attach to) are soldered to a circuit board, making sure that the car will be off and stay off for a day or two, you can spray a contact cleaner in the area where the shaft onto which the knob attaches depresses into the stationary section of the shaft.

In my case, I used quick drying, plastic safe QD electronic cleaner, such as this one, which I got from Walmart for like $3, and used the attached straw to spray directly on that spot of the shaft.

I then worked the knob, pressing it, releasing it, turning it back and forth, and turning it back and forth while depressing and releasing it, spraying the cleaner a few times in each position.

In my case, the "clicking" or "detent feel" softened a little when turning the knob, and the "clicking/detent feel" for both the fully extended and fully depressed positions when pressing and releasing the knob no longer exists. I'm guessing that there was something inside the shaft (like a grease, which under pressure from pressing the knob would mimic a spring) which was dissolved by the cleaner.

After letting the cleaner dry (if you don't remove and disassemble your HVAC control unit like I did and you simply remove the knobs to do this cleaning while the unit is still installed, be sure to keep the knobs off and blow some warm air for a while to dry the cleaner), I then reassembled and reinstalled my unit and tested it, and it worked great...except that the fully depressed and released positions were too vague to stay on or off reliably. (In other words, simply turning the knob could depress it just enough to turn it off, and it would require pulling the knob to make sure it would stay on.)

To restore the press and release feel, and to make sure the knob would stay in the released position, I found a spring that would fit over the pulse generator shaft and sit between the pulse generator and the knob to push on the knob. In my case it was a Hillman #127 spring from Ace Hardware like this one.

I then reassembled everything and tested it, and the press and release (and stay released/out) worked great...except that turning the knob would cause a binding between the knob and top of the spring.

To solve that, I found a M6 flat washer that has an outside diameter small enough to fit in the inside diameter of the red and blue (heat and cool) indicator which the knob fits into (this also was found at Ace Hardware in the metric hardware bins), and then installed the washer between the top of the spring and the knob.

I then tested it and everything (pressing, releasing, turning fully 60 degrees to 90 and back) works great...and that has remained the case for three days now.

I'll try to post pics to clarify my descriptions ASAP.

(As for why knob turning would fail to generate smooth pulses before this cleaning, I'm guessing that the grease/substance/material inside the shaft fouled the pulse generating contacts/functions.)
 

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2006 STS (1SG LH2 M22 JE5 FE3 F55 Q12 T43 K59 UV6 TT6 TQ5)
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62 Posts
The bottom line:

Cleaner: about $3.

1 spring for each knob: I think $1.50 each...maybe they were less...and this is only if your "clicking/detent feel" for pressing and releasing the knob is affected by the cleaning like mine was.

1 washer for each knob: about $0.14 each.

Something to circulate warm air into the knob holes: probably free if you have a heat gun or hair dryer available.

Time to run to the hardware store and back: depends on where you live.

Time to remove the knobs: 90 seconds using my description.

Time to spray and work the knobs: 4-5 minutes.

Time to blow warm air in the knob holes: maybe at least 30 minutes to be safe, or just let the car stay parked in a warm place for a day or two.

Total: less than $7 and as little as (or even less than) 45 minutes to an hour!
 

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2006 V6 STS RWD
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305 Posts
Good writeup. Maybe just a container of "canned air" like you'd use to clean a keyboard or similar to speed the contact cleaner evaporation? I'd probably just leave it, as it flashes off pretty quick regardless.
 

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2006 STS (1SG LH2 M22 JE5 FE3 F55 Q12 T43 K59 UV6 TT6 TQ5)
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62 Posts
Good writeup. Maybe just a container of "canned air" like you'd use to clean a keyboard or similar to speed the contact cleaner evaporation? I'd probably just leave it, as it flashes off pretty quick regardless.
"Canned air" would help for applying air pressure to disperse any pooling of the cleaner--but it blows VERY cold, and the warmer the air, the faster the flashing off, so be sure to give it some time or warm air flow to flash off after blowing canned air.
 
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