Mechanics

MIXED AIR SERVO

2007 Toyota Camry • 4 cylinder FWD Automatic • 200,000 miles

Mixed air damper not switching between hot and cold. All controls seem to work, the blend controller (under radio) has the A/C switch on it which does work. No blinking lights or anything abnormal. No codes on OBDII, I have tried a new a/c amplifyer and have taken the servo motor out and switched it- still nothing. Any idea's.
I have taken it to a Toyota Dealership who simply stated it needs a new airbox for 2600.00- after explain all this to them as well. Pretty sure there should be some voltage patterns to follow. Cannot believe an entire airbox is needed as everything works except the signal to open this door. Door does switch freely when the motor is out so it is not a mechanical issue there.

Will totally donate towards this if I can get it fixed- 2 was the min. Will totally up that if there is an answer
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Tpayeg
June 19, 2014.




This is a tough one. The air mix damper servo sends a pulse signal to the amplifier. That is what actuates it. Has that been checked? Also, have you checked for trouble codes using a scanner that can read these types of codes? I attached a schematic of the interaction between the servo and amplifier. See if that helps.


I did take it to a dealership so they could troubleshoot it with the Toyota scanner. Had the dash all apart with easy access too. Still the tech, seemed more lost than I was, which is not good when paying 140.00 an hour.
I understand how it all works, mostly, I guess I am looking for some kind of values to see if a signal is indeed leaving the controller, or one coming out of the a/c amplyfier, or even something at the servo connection. The only other thing I can think might do this is a fault at the inside air temp sensor (?).


Tiny
Tpayeg
Jun 19, 2014.
I just searched my manual and found nothing as far as values are concerned. I did find a better schematic but I can't seem to upload it. I am assuming this is an automatic climate control system.

You know, I have a ton of info to check from, but everything requires a DTC. I tried looking for specific values as requested, but the manual doesn't let me find them without the code.


I do have the wiring schematic for the whole car, a/c included. No values listed either. Funny how you could probably do it with the DTC but the Toyota dealer could not.
Well, if you do find something, or if someone out there can please do advise- Not willing or able to put an entire airbox in and I am certain there is a simple way to check for a signal and follow it to its cause.
Thanks for everything thus far and I do hope this can be solved.


Tiny
Tpayeg
Jun 19, 2014.
Did the dealer tell you they can't check it for codes?


The sheet simply stated needs an airbox. I called and talked to the service manager as this seemed odd and not anything near what I am used to. She stated that they checked all connections and ran it through the computer/ readers. Still, this has to be the worst service I have ever heard of, not going to get into a mud slinging thing at all- just frustrated. I am going to try and replace the heat/ac controller next week and see if that is it, but in my experience usually there is a flashing light when they do not work.
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Tiny
Tpayeg
Jun 20, 2014.
I agree. Usually there is something to indicate a problem such as a blinking light. It's funny, but the scanner I use cost me nearly 600.00 and it can't read these types of codes. That is why I suggested the dealer. If I had a code, I feel really confident that I could be more help to you. Let me know what you find or if you can find someone to check it for codes.



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