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Toyota Avalon Climate Control Questions



  • my avalon recently started running on low even when i switch it manually to high. sometimes it will go to normal speed then to low and repeats. no pattern to it just random. checked the blower and it's fine. i've read that the xls does not have a resistor but then i have no idea what would cause this. any ideas would be greatly apprecciated.
  • Anyone know if the '95 Avalon XLS has a cabin filter behind the glove box, like later models?
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaPosts: 58,448
    Not it doesn't. That's comes in about 1999 on the Avalon I think.

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  • A/C blowing hot air. Going to take it to an independent shop, but wanted to see if there are any issues that might cause this besides needing a new compressor. Any Ideas??

  • jeal1jeal1 Posts: 4
    I posted this question in the 2008 Toyota Avalon section and then came upon this forum. So, here it is again.
    When I set my Avalon's passenger temperature to anywhere between 74 and 80, the back vents blow out air at 107 degrees which makes it impossibly hot for anyone in the back seat. The passenger in the front has to freeze or the back seat passengers have to burn up. Anyone else having this problem?
  • tjc78tjc78 JerseyPosts: 6,651
    I don't think its a problem at all. From what I remember from when I had my '06 Avalon that is just the way it works. FWIW I never had to set the heat above 68-69 or the car blew me out of there it was so hot.

    2017 Buick Enclave / 2017 Hyundai Elantra

  • I am hoping someonce can help or has worked through this. My wife drives a 1997 Avalon XL. Has about 130k. The car gives very little heat. The engine does not overheat. The AC works fine. However, you have to be driving for a while with airflow on recirculate to build up any significant heat. I've had the timing belt and woater pump replaced just this past summer (July 2009). I use long life coolant whcih is reccommended by the dealer and there are no coolant leeks.
    Please help! My wife hates the cold!!

  • finfin atlantaPosts: 591
    Here's some general thoughts, others will have to give you more exact details. Your cooling system works, the car operates and does not overheat or leak. That means the warmed coolant is not getting to the heater core that allows the heat to be blown to the interior of the vehicle.

    There is a control valve that diverts coolant to the heater core. This valve is not opening. Or the hose to it is stopped up due to age. Or the heater core is plugged in places with residue. Or the control switch is not telling the valve to open. Or the return line from the heater core is plugged. Or a combination, this is a 13 year old car. (It's not the coolant or the water pump.)

    A coolant flush with the new pump should have revealed the problem. But if you just had this work done and have never had the problem before, the repairs may have caused the problem. In order of simplicity, step one might be to ask the dealer to check his work and see that all lines and wires have been properly re-attached. After that, check the valve and hoses. Last, look to the heater core. Hope this helps...
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaPosts: 58,448
    Aside from the possibility of a defective heater valve (good guess!), did they replace the thermostat at the same time as all the rest? If not, they need to be slapped. :P

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  • wwestwwest Posts: 10,706
    I will assume the heating was fine until last summer so your most likely problem is a "void", vapor lock", air bubble, in one of the hoses to/from the heater core. When the coolant was being refilled enough "care" was not taken to avoid this.

    Toyota has not used a heater core water flow shutoff valve for many years now, going back to the early 90's..
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaPosts: 58,448
    It's called a "water control valve" and is cable operated, but wwest is right, it's not at the heater core, but in the engine bay.

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  • finfin atlantaPosts: 591
    YES ! Thinking outside the box.... My focus was on the heater and controls but a defective t-stat, stuck open or other malfunction, could produce the same symptoms with all else working OK. It would also lower gas mileage slightly as the engine will never hold optimum operating temperature in winter. :)
  • wwestwwest Posts: 10,706
    You might want to check first and be sure the water control fully opens when you move the control to MAX heating. Valve is close to the firewall in one of the heater hoses.
  • Ah! Toyota Avalon and its bloody stupid heating and cooling system.
    My 2001 has perfect air conditioning but heating is garbage...went to dealer and they say these cars don't heat too well. Big problem is that the car heats sort of o.k on the drivers side, but passenger freezes.
    The dealer wanted $ 3000.00 to replace some flap that does not open or close close to the heater core. I think it is shameful of Toyota to not own up to this obvious bad engineering.

    Anyway, you say the heat does come but only upon recirculation. That tells me that the the heater core is not warming up enough for the fan to blow hot air over it but keeping stale air in does a bit of a trick.

    I would try and find the highest degree or "hottest" marked thermostat I can find and install it. Someone suggested it and I am certain that the thermostat is old and is stuck in an open position.

    I am always a bit ticked off when someone says " hey, the car is 13 years old"
    So what! I have a couple of cars that are 17 and 22 years old but apart from some routine parts like water pumps, alternator etc...I have never had to piss around with this dual air climate nonsense that Toyota suffers from. My 19 year old Audi never ever had heating or cooling problems. :blush:
  • Thank you all so much!! I am re-reading the posts to see what the best course of action is. I made a mistake in my post. My wife's Avalon is a 1999 not a 1997.
    I was thnking about my truck for a moment. Sorry.
  • my wifes 98 avalon is having trouble with the blower, it only works on low now. it was working intermittently but stopped doing that too. i tried replacing the blower relay did nothing. tried replacing the blower, nothing. just don't know what else to try. it has the automatic climate control, should i replace the controls? any ideas would help tremendously.
  • boxstackerboxstacker Posts: 1
    While making slow left turn in 08 Avalon my AC or heat turns off .. Dealer claims I accidently shut off ... this happens daily..and always at slow speed.
  • I have a 96 avalon that i bought 6 yrs ago. I have never had any problems until now. My a/c had always almost overworked. Making my car very cold. now it only works maybe 2-3 days then gave out very little air for about a month.
    When i would drive it and make turns i could hear water swishing but could not tell where it was coming from.
    I wonder if anyone else has experienced this. If so, could you tell me short of taking it to a mechanic what was done to fix it.
  • I own a 2007 Toyota Avalon and am having the following problem.

    When the car is stopped at a traffic light or in park and the AC is on, the RPMs will fluctuate. RPM will increase by 250 - 750 above idle every few seconds and then drop.

    The symptoms go away when the AC is turned off or set to MAX Cold Temp and High Fan. Fluctuations are greater when the AC fan is set to its lowest speed.

    Any ideas?

  • wwestwwest Posts: 10,706
    SOP, the engine "idle" RPM is changed as the A/C compressor clutch cycles, engages and disengages due to refrigerant flow demand. Lower blower speeds, in general, make the system more efficient and thus longer cycles.
  • fsimcicfsimcic Posts: 1
    I have an 06 Avalon XLS with 138,000 miles. I have started having this a/c problem where the compressor just seems to stop working. I can tell by the smell! Toyota told me it needs a new compressor at the cost of $1800.
    The issue though I can press the AC button on and off within a second and the AC starts working again instantly! I do not think it is a compressor, but I can not find a blog that discusses this particular problem.
    I am hoping that I will get a good answer here to tell me what to look for or what to mention when I take it to an AC mechanic. I want to kinda know what I am talking about.
    Thanks to all that comment.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaPosts: 58,448
    You may wish to consult your owner's manual for testing purposes. The system in your car is quite complex and uses various computers and sensors to control the compressor. :

    SELF-DIAGNOSIS: Air Conditioning ECU has a self-diagnosis function. It stores any operation failures in the air conditioning system memory in the form of DTC (Diagnostic Trouble Code).

    There are two methods for reading DTCs. One is to use a hand-held tester, and the other is to read the DTC on the heater control panel switch.
    DTCs are shown on the center display or multi display of the multi-information display, and on the hand-held tester.

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  • Could you please tell me how one gets the DTC on the heater control panel switch?
  • I just bought a beautiful '99 XLS Platinum Edition today. Then on the way home the climate control quit working. (Now) I know that much has been posted here on this topic. I'm hoping that I don't have to replace all those expensive parts. The only thing that might save me is the one 10 amp A/C fuse inside the passenger side kick plate noted in the owners manual. But, I can't find it. I stood on my head inside the car trying to. Is it really there? If so, can you help me locate it?
    Many thanks
  • On my car, I lost the climate control, but also, the outside temperature display also went out at the same time. Mine turned out to a be a part they called an amplifier. Why it's called that,I have no idea,but it cost $800.00 from Toyota to replace it. I thought it should have been a recall because of losing the defrosters ( safety issue). But Toyota thought differently!
    Good luck.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaPosts: 58,448
    So you don't have an owner's manual?

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  • hogrider47hogrider47 Posts: 1
    edited September 2011
    Air conditioning seems to work okay in weather up to about 85-90 degrees F but quits when it gets around 95+ especially if I park the car and start it back up. It seldom works until the air temp gets back below 90F If it does work (cycles on and off just long enough for you to begin feeling cool air come out and then goes off) it is never cycling long enough to cool the inside of the car. It is usually so hot inside we have to roll the windows down. I've taken to A/C mechanic and he couldn't find anything wrong. Compressor okay, charge okay. Works and cools great in shop. Same with dealer although they just checked the charge and said compressor is okay. On the drive home it quit working again (102 outside temp). Anybody got any ideas?
  • greeseegreesee Posts: 1
    I have an 1998 Avalon XLS which is parked outside under a hot summer sun. When I would enter the hot car and turn on the A/C, it would either run for 30 seconds or not run at all. All buttons and indicators would not work nor light up. After a considerable cool-down, everything worked fine. After some experimentation based on what I have read here and elsewhere, I decided that before I turned off engine, I would leave the "AUTO" button on, and the temperature selector at lowest temp setting. Thereafter, upon starting the hot car, the A/C worked fine for several years. About a month ago, my system failed once. I then decided to go "manual and avoid "AUTO." The following buttons are depressed: "Air Intake Selector" on recirculate, "A/C," "Air Flow Selector" is on to the face, "Fan Speed Selector" is on Hi, "Temperature Selector" is at lowest setting, and "AUTO" is not depressed. This works great, even on temps over 100. It would seem that Toyota's faulty amplifier cannot take the heat and shuts everything down and it will not reset until it is cool. I hope this info saves somebody lots of money.
  • I own a 2007 Avalon XL, which I have maintained with care. It has generally been a smooth-running car. The XL has a blue screen, known as a multifunction display (MFD) in the center console/dashboard, above the radio, that shows climate control settings, audio information, outside temperature and mpg. The other trim levels have a navigation system in the same location. About a month ago, the MFD began to flash on and off. Occasionally, the screen went blank and climate controls did not work, although heat or A/C continued to run. Steering wheel controls did not work either. The problem was intermittent. The radio, a Fujitsu Ten (non-JBL) began to lose its presets and turn off by itself after about 10 minutes. The radio could be turned on again after an interval, but wouldn't stay on. Whenever the radio was turned on, the MFD problem started. The display turned off and on, and sometimes went blank. The radio now works only for a few minutes, and the station or band can't be changed. The dealer couldn't find the problem on the first visit; they spent 3 hours trying to diagnose the problem. On my 2nd visit, the radio issue was apparent and now they want to replace it with a rebuilt radio head unit - cost is about $600. I am wondering whether the radio alone is the problem, or whether it is something else - the MFD itself or a harness. The car battery is fairly new and there are no apparent electrical problems beyond this area. Anyone have any thoughts, or a similar experience?
  • I will answer my own post. The Toyota OEM radio is designed to serve as an electronic "pass-through" for the climate control system. The climate control wiring runs through the radio. The objective is probably to make it difficult to use aftermarket radios. This is also discussed in the audio section of this forum. My radio began to fail, and as it did so, the climate controls and displays were affected. After a rebuilt radio was installed, the problems with the climate control appear to be gone. Thus, if something happens to your climate control system controls, the radio can be the culprit.
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