Weird problem that isn't really causing any trouble yet, but lately every time I start the car the ECC temperature (either the set inside temperature or the outside thermometer) blinks. The icons indicating which vent is outputting air, as well as the *F symbol do not blink, just the temperature. It doesn't always start blinking right away, sometimes it takes a couple of seconds. I found I can make it stop by hitting the temperature adjust button to bring up the inside temperature, and then turning my ECC completely off and then on again. It will continue to blink a couple of times before stopping. Can't say right now whether it seems to affect the air output temperature or not.

Any ideas what might be causing this? Once it stops blinking it controls air temp and flow just fine, so I don't think my ECC is going out.
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Ever searched for "blinking ECC"? You will find you are not alone.

It'* an HVAC error code.

Read this, even though its for a Bonneville.
http://trialsnuts.com/ecc.pdf

Often the dreaded blinking ECC indicates a bogus airmix actuator, but I think I'd have someone read the code yours is throwing to see what it may be. If it says something about needing calibration, you may have an airmix actuator preparing to bid you a fond farewell.

Wow...that sucks.

Would the airmix actuator make any noise if it'* going out? I've been hearing creaking behind my dash everytime the airflow is automatically adjusted from high to mid or low or some combination of the three.

How would I go about getting that code scanned?

By the way: I also recently disconnected my battery to change the alternator. It started doing this afterwards I think. It may have done it once a while before, but no more.
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Here'* a little update to help answer my questions. I took it for a short drive and found this:

When car is first started and ECC begins to blink, vents are routed to the floor and hot air is blown.

After I turn the ECC off and on again, vents route back up to "mid" and blow cold air just like they're supposed to. ECC continues to blink for a few minutes and then stop. If it weren't for the blinking ECC (and the initial blast of hot air) I wouldn't even know there was a problem.

Hope this helps narrow my problem down somewhat.
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I'd need a little verification from someone who knows for sure, but I think you could take your car to, like, AutoZone, and they could put a scanner on it. Certainly a dealership could read those out for you.

Before you take it to a dealer, though, you could pull the glovebox out and, with a flashlight, peek through the hole in the dash brace and observe the motion of the airmix door arm. Refer to the link provided earlier for pictures. If the arm doesn't move smoothly from one extreme to the other (as you set temp to max heat/max cool), you have an issue with your actuator.

I'm making the assumption, of course, that your Buick is similar to a Bonneville in the under dash configuration.

Autozone will not be capable of scanning HVAC codes. The blinking is you HVAC system saying it has a problem and that the HVAC programmer has stored a "problem code". What the code is can only be determined by using a "Tech II" scanner (All GM dealers and most larger shops have them). There are about 7 or 8 diffenert issues that will set a code and then casue the ECC to blink, including air vent faults, airmix actuatro, loss of memeroy, etc., etc.,. It will continue blinking as long as the programmer detects a problem. If the problem ever gets fixed (or corrects itself), the blinking will stop after 50 drive cycles of not identifying a problem.

At this point, based on your description, it is hard to tell, unless something actually fails for good, what issue it is having. If the HVAC system eventually works as you adjust things or restart the car then it is tough without getting it scanned to pin-point what is actually happening.

Thanks for the help guys. I'll try the "ignore it for a while and see if it goes away" method because I'm not too sure I want to pay $75 at the stealership to have them scan my code. Unfortunately, I don't drive it too much so there'* no telling when that'll be.

This intrigues me, because as I said I had just disconnected the battery. Perhaps this is all it is.
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Well, on a little pleasure cruise today I found out what it was.

I was burning up, I couldn't figure out why. The air coming out of the vents was cool, not cold...but cool. Yet I was burning up. Reached over to feel the passenger'* side and whoa...fire hot air was coming out.

Got home, popped the glovebox, and played with the temp controls. The airmix arm moved very little, if at all. For some reason the driver'* side only blew cold air, and the passenger'* side blew only hot air. Disconnected the airmix arm and moved it around myself. Boom, I've got cold air coming at my face from the passenger'* side. That creak I heard? The actuator. When I saw it barely move I heard a creak. I guess today it finally went out for good.

Check this out though:





Gotta love the LeSabre. The airmix actuator is very easy to see and get to. Had I been in possession of a quarter inch ratchet and a new actuator, I could've had the old one out and a new on in within 15 minutes.

I'll see where to get a new actuator, but for the meantime I may just tie the arm off to full cold to get by.
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Good job pin pointing the route cause of the problem.
Keep us informed as your progress on fixing this problem is completed.

When you have fixed it, please end your post and mark it as "Fixed"

This way when others have run into this problem with there cars they can find posts with solutions to problems, not open ended problems that give no real fix.

Thanks

Keep it up!


Todd