Toyota Highlander Heating Ventilation and Air Conditioning

alleycat7alleycat7 Member Posts: 3
edited March 2019 in Toyota
i have a 2005 Toyota Highlander with approx. 12,000 miles on it and the air conditioning works intermittantly. Since the problem is not all the time i'm afraid i'm going to spend make many many trips to the dealer trying to get them to find the problem. Has anyone else had this problem with the A/C working now and then??
Thanks for your replys


  • slimesslimes Member Posts: 1

    I have a 2003 v6 Highlander 4WD. It has the manual 3 knob controls for the heater. I am looking to switch it to an Automatic Climate control. Can this be possible? If so what do I need to get this done? Someone told me that the wiring is different.
  • wconnors1wconnors1 Member Posts: 3
    Hi Slimes,

    Was checking the forum and noticed your question. I know it was Dec 31 when you posted, but have you done anything with this. I too, was considering changing to Automatic Climate Control in my 01 Highlander. Were you able to accomplish this or is the wiring indeed different? I already have a replacement panel. Thanks,

  • kenlwkenlw Member Posts: 190
    can you describe the symptoms a bit more; like when it isn't working, what is it doing, blowing warm air? Does the fan remain on? Does the compressor stay on? etc
  • alleycat7alleycat7 Member Posts: 3
    Yes the fan stays on and the temperature control works. I get the cool air or warm depending on where the control knob is. When i push the AC button it doesn't light up and there definitely is no cold air coming out. Just air----
    I'm wondering if when the radio/CD had to be replaced if they messed up something then and it has just now shown up. The whole radio system died last month and had to be replaced :)
  • kenlwkenlw Member Posts: 190
    I think the system may just be low on freon. You can have it checked, but since freon doesn't disappear on it's own it usually indicates a leak somewhere; which depending on where that leak is can be expensive.
  • alleycat7alleycat7 Member Posts: 3
    I took the car to the dealer today and they said they readjusted the control knob. Sounds like of "iffy" to me but the AC does work now so we'll see. If it goes off again it'll go back right away. My warranty expires in December so i want this stuff fixed before that.
    Thank you for your reply and help :)
  • ggartnerggartner Member Posts: 3
    I have 2002 Highlander. Had my evaporator replaced today. When they put the dash back together, the compressor will only come on when control is on Defrost. Any ideas?
    Thanks, Gary
  • donivanfdonivanf Member Posts: 1
    I'd like to also convert my '05 Highlander from manual to automatic climate control. I pulled the controls out last night and was able to match the main plug with a photo from an automatic climate control from an '04 Highlander. However I do not see a plug for the fan switch control, and I'm afraid there might be some electronics involved here. I bought it anyway, and am going to try. I may have to get the wiring diagram book ($$$) but it's a start... I'll post back if I have any success.
  • phrosutphrosut Member Posts: 122
    I already have the auto climate control but I wanted to mention that the complete service manuals on CD I found on eBay for ~10 or 15 bucks if I remember right (I bought them when I bought our '03 HL in 10/02).

  • 1rodger1rodger Member Posts: 1
    I have a Toyota Highlander that doesn't provide heat for the cabin. The engine temp gauge is normal, but I'm getting cold ambient air from the vents. I have been using the A/C lately but tried heat today due to a cold snap. Is there some system that bypasses hot water from the cabin? My wife was driving and she heard a "pop" and remarked that the car never warmed up, I drove it this morning and there was no heat in the cabin. The coolant level is normal. The thermostat must be working or the car would overheat if stuck closed, or over cool if stuck open.
  • derekgaddyderekgaddy Member Posts: 32
    I have a similar problem. I have electronic climate control and I only get hot air if my controls are above 77 degrees or so. Any idea what the problem is? I hate to go to the stealership. Help!!
  • teresa72kcbteresa72kcb Member Posts: 3
    2001 Toyota Highlander - instrument panel lights for clock, AC, air intake won't light up. When heater-defogger is turned on, hot air blows out air conditioning vents, but no warm air comes out windshield vents. Makes for very dangerous driving conditions in cold, wet weather. Help!
  • disneymom3disneymom3 Member Posts: 4
    I have an 05 highlander that I bought new and I am having that trouble right now, however mine has now stopped working on the heat side. Guess what, it's the control panel and it is going to cost $740.00 for the part alone. Go get yours fixed right now if it is under warranty.

    I am trading mine in asap for something else. With the other problems that I have had, I will not be getting another Toyota. :mad:
  • cpipercpiper Member Posts: 1
    The other day, the A/C started blowing hot air and the A/C wouldn't work. Another $600 bill I thought... A friend recommended a small garage so I took it there. The mechanic checked the temp. of the A/C pipe in the engine compartment and found it was cold. He pulled off the large dial..the one going from hot to cold... and found that the switch behind it was loose and on hot air. He tightened it up and the A/C engaged.
    Cost:0$ but a $20 tip!
  • webgoodwebgood Member Posts: 95
    This appears to be a major source of complaints, particularly as the HL's get older, and has been addressed in other posts, but maybe not so clearly. The temperature control knob in the center begins to feel a little "wobbly". It should be nice and firm when turned and you should slightly feel position indents or stops as it's turned. Pull straight-out on the knob, it comes right off, and tighten the retaining nut on the control post, push the knob back on. Same for the airflow direction knob to the right.
  • kleutsterkleutster Member Posts: 3
    I have an '04 Highlander. I will get heat intermittently, even though the engine is hot and the temperature knob turned fully to the right. Turning the knob to cold and then back to hot usually works, but often it takes 2 or 3 times. Sometimes heat is coming out, and then is just goes cold. The knob isn't wobbly. Any ideas?
  • webgoodwebgood Member Posts: 95
    Sorry kleutster, I don't know enough about the inner workings to venture an intelligent guess. But, just for the heck of it try checking the temp-control assembly...grab the knob with all your finger tips and pull straight out. It comes right off and will slip right back on. Check the assemble to see if it's locked-down in place with the nut. Beyond that, off to the Toyota or import car specialist. Regards, BGood :confuse:
  • ladyk1ladyk1 Member Posts: 1
    I fixed my Highlander's temperature control problem, thanks to looking it up and finding out about the wires that broke. Long story short, I called Toyota to see if there were a lot of complaints about this being reported. There are web sites everywhere that address this particular problem, yet Toyota doesn't acknowledge a problem. I would like to suggest that everyone who has had, or is having this problem, to please call and report it. The number is 1-800-331-4331. Perhaps they will design it better next time, or maybe even recall it (but I doubt it). Anyway, I saved about $800-$900 by fixing it myself, rather than take it to Toyota. Thank you to all who posted info about this problem.
  • kleutsterkleutster Member Posts: 3
    Hey Webgood,
    After posting my problem (#19), decided to check if the nut on the heater knob post had come loose. Sure enough, it was loose enough to cause the irregular heating issue. Amazing. I'm so glad I found this forum and your posting. It saved me hundreds of dollars, I'm sure. Thanks again.
    To everyone else, it's an easy thing to check and rule out.
    As Webgood said, the heater knob should be nice and firm when turned and you should slightly feel position indents or stops as it turns. Mine didn't until I tightened up the nut.
    Pull the heater knob straight off and feel if the nut is loose.
    Keep spreading the word. :)
  • webgoodwebgood Member Posts: 95
    Hey kleutster, that's great! I can't take credit for it...wise and experienced people discovered it and posted here on Edmunds some time ago; I just passed it on. Thanks to Edmunds and the moderators for hosting such a great and resourceful forum!!
  • chuck58chuck58 Member Posts: 1
    I've been using the AC to cool since it has been getting warmer over the last week and everything has worked fine up until this evening. Strangely enough, at the same time I noticed that the fuel gauge is stuck at 1/4 tank. This morning I ran it pretty much down to E before filling it up to full.

    I plan on checking the AC knob to fix the AC problem tomorrow but have no idea about the fuel gauge. Could these possibly be related?
  • webgoodwebgood Member Posts: 95
    Chuck, I can't imagine how they could possibly be related. The AC knob is real quick and easy to check and fix, but the fuel gauge...that's a whole 'nuther can of worms (could be in the tank itself or the dash gauge or wiring between them). Sorry. Good luck & let us know. Regards, BGood
  • webgoodwebgood Member Posts: 95
    I neglected to mention, do a search in the discussions for 'fuel gauge', you'll find some interesting info in Maintenance and Repairs that might apply. Regards, BGood
  • jahossjahoss Member Posts: 1
    I called Toyota in Concord, CA and they told me rather curtly that is would be $149 to diagnose the problem and up to $1,000 to fix and the guy just couldn't give me anymore information on about why the heat wasn't working on my 4 year old Highlander.

    I found this site after a general search for Highlander Heater Problems. I did as they said, "take the knob off, added a drop of Loctite, and tightened the nut." It works. I'm sending a copy of this post to Toyota. What lousy customer service from the dealership where I bought my car and have had all my previous repairs done.
  • thaimthaim Member Posts: 1
    My '01 Highlander started doing this exact thing in March. I was worried that it'd be a costly fix, but after Google led me here I'm pretty confident that pulling the knob off mine and tightening the nut will be the fix. Thanks guys. Great find.
  • webgoodwebgood Member Posts: 95
    Lots of good info here! :)
  • vdeamvdeam Member Posts: 1
    I took my 2003 Highlander in to the dealership in Dublin CA this morning. They called me at lunchtime to let me know it would cost $1100.00 for a new A/C controller. I found your message on through google and decided to give it a try. IT WORKED. Thank you so very much. My only regret is that I didn't find your message before I took the car in because the dealership charged me $150 just for looking at the car! :)
  • ggartnerggartner Member Posts: 3
    Glad it worked for you.
  • jazzbelljazzbell Member Posts: 1
    Hmmm - I'm one who paid the 1500.00 for the new unit (hadn't found this website).
    When I picked it up - they didn't have the colored decal on it and told me I could pick it up today. I went to get it put on - and now they want an additional 40.00 just for the decal (looks awful without). Has anyone else run into this??? They said, "well that's toyota for you" - Needless to say I didn't buy it (yet). Does anyone know where I can get a colored decal for the unit without paying yet another sum of money???! I am really choked about this. Thank!
  • pprideppride Member Posts: 1
    I am having the same AC issues and have the auto climate control panel. Can you clarify the "knob" that should be tightened to fix this or is it both? My panel has the temperature knob on the left and then the blower control on the right. I presume it is the temperature knob that I pull off and check? Please confirm.
  • webgoodwebgood Member Posts: 95
    I'm not familiar with the auto climate control layout. You didn't say what year HL you have. My '04 layout is, left to right, 3 dial-knob selectors:
    L=fan speed Center=temp select R=discharge outlet selector

    The one that's been an issue is the center temp control.
  • kleutsterkleutster Member Posts: 3
    Yes, that's correct. Check which way the arrow is pointing on the temperature knob before you pull it off, so that when you push it back on, you align it the same way.
  • kenlwkenlw Member Posts: 190
    "Yes, that's correct. Check which way the arrow is pointing on the temperature knob before you pull it off, so that when you push it back on, you align it the same way."

    better yet, turn it all the way (either way) before you remove it, then it will be easier to get it back aligned the same.
  • luckybellyluckybelly Member Posts: 15
    I got 01 Highlander V6 with non-auto temp control.
    My A/C is fully charged but intermittently I don't get cold air. I know this cuz I have used temp guage and know the temp when cold and warm. The temp setting knob works fine. But do not get cold air, while driving intermittently it will start sending cold air but consistently.
    Anyone run into this problem and know the fix. Any help is helpful.
  • nimrod99nimrod99 Member Posts: 343
    Dublin Toyota service / dealership are crooks
    never take your vehicle there. I would say 90% of dealerships are crooked
  • wwestwwest Member Posts: 10,706
    If the engine coolant is approaching the level of overheating, not yet at that level, the A/C will be shut off to keep the condensor from pre-heating the airflow to the radiator. Once the coolant temperature drops back to the normal range the A/C will start up again.

    Being stopped for awhile or moving slowly along in stop and go traffic with the engine mostly idling and A/C still going on a hot day will result...
  • luckybellyluckybelly Member Posts: 15
    Coolant temp guage shows normal temp.This happens while driving at normal highway speed and on streets. It intermittently works fine and then it doesn't.
    Are there sensors that prevent it from turning on?
  • khenkelkhenkel Member Posts: 1
    Here in the Las Vegas summer heat the A/C doesn't get the vehicle to cool as quickly as expected (+20 minutes).

    Has anyone else had similar problems?
  • grahampetersgrahampeters AustraliaMember Posts: 1,786

    I'd take it to the dealer as it has probably lost some gas. The Air Con is super efficient and copes well with Australian summers (similar to Nevada) so there sounds to be something not wrking correctly


  • wwestwwest Member Posts: 10,706
    The human comfort equation involves air temperature, humidity, and radiant heating/(cooling) effects. If you let the car set out in bright sunlight with the windows rolled up the interior will (over)heat to such a great level that it might take an hour with a dark or black interior for the A/C to cool the interior surfaces enough that their radiant heating effects on your body can be overcome by the A/C cooling airflow.

    There are times when Toyota's design engineers seem to be a little TOO concerned with passenger discomfort and "this" is undoubtedly one of those times. You can be cool the cabin down quickly by discomforting yourself briefly with system airflow that is a bit TOO cool.

    First, move the temperature setpoint to the COLDEST position. That should result in the blower speed going to the highest level once the A/C begins cooling the airflow. It will also, typically, result in the system switching to recirculate mode. If so then immediately switch it back into fresh mode and lower the rear windows an inch or so.

    The object of this "stage" is to move the "super-heated" airflow out of the passenger cabin and in the process hopefully reduce the interior surface temperatures slightly.

    Over time and trials you will begin to be able to judge when to switch to the next stage.

    Now switch the system to recirculate mode and lower the blower speed to adjust your noise intrusion comfort level. At this point the lower the blower speed is the lower will be the temperature of the system airflow. If you continue to need it cold, TOO COLD, in order to more quickly cool down the cabin then you might want to switch the airflow to footwell or mixed dash/footwell mode.

    I found it helped quite a bit cooling wise, COOLDOWN, to purchase and install a manual water flow shutoff valve in the engine coolant flow line to the heater core. That not only serves to bypass the reheat.remix mode of the HVAC system but results in a significantly lighter load for the A/C compressor and thereby an improvement in FE.
  • kenlwkenlw Member Posts: 190
    Not to disagree but the heater bypass valve should already be closed (actually, in bypass mode) when the temp is on "cool" and the outlets are not on defrost.

    To cool a car down quickly after sitting in the sun, 1st put down ALL the windows, switch the AC to NON-recirculate and the highest fan speed. After about 1-3 minutes of driving, roll up the windows and switch the AC to RECIRCULATE.

    Why? The fastest way to move the cabin temp down from 140 is to get it to 100 by rolling down the windows. Then let the AC take it from 100, instead of trying to make it work against 140 air.
  • wwestwwest Member Posts: 10,706
    "heater bypass valve should already be closed..."'

    If you mean the reheat/remix vane/door then it will only be fully closed, and REMAIN fully closed, with the system in the max cooling position. On the other hand if you mean the actual coolant flow valve then the beancounters have been successful in eliminating that feature some years ago now.

    If the hot engine coolant is allowed to flow through the heater core then the radiant heating effects can be rather substantially adverse to the cooling capability of the system.
  • tonneytonney Member Posts: 1
    My 03 Highlander has a similar problem. When either the fan/vent or A/C is on, every once in a while the heat starts blasting. Very inconvenient. Had this diagnosed today - a resistor in the circuit board behind the panel will have to be replaced...$1,100!!!!

    Anything like this out there???
  • irishcaseyirishcasey Member Posts: 36
    Yes, my 2002 V6 Highlander with manual ac/heat controls is also exhibiting this same condition. With the temp dial on blue (cold) and the fan on and the a/c on it periodically and intermitently blows warm air rather than cold air. It will do this for maybe 10 to 15 seconds and then go back to blowing cold air. So just $1,100. Are you going to get a second opinion?

    Also my V6 is using excessive oil and has blue exhaust when started in the morning. My dealer insists on measuring the oil usage requiring me to take it to them periodically to measure oil. Last trip used a quart of oil in 500 miles. I'm aware of the slug settlement but my dealer pulled the head cover off and told me there was no sign of slug. It's not sounding like they want to help me.

    Anyone have any suggestions, please help. thanks.
  • texastoolguytexastoolguy Member Posts: 1
    I had same problem a few weeks ago. It started about a month ago and it gets progressively worse. Toward the end. My AC was fine if ambient temp was below 80 but the hotter it got outside the hotter the air blew inside. Kind of defeats the purpose of AC. Dealer say it's a known issue but my extended coverage expited in May and it's dang hot here in TX... I paid the 1 K for the PWBA and it fixed it.
  • bdymentbdyment Member Posts: 573
    I am curious. What is PWBA?
  • jtumisjtumis Member Posts: 3
    How do we fix it? What is a pwba? Can I do this myself?

    Perhaps letting Toyota know may do something? &p_lva=&p_sp=&p_li=&p_accessibility=
  • mikefm58mikefm58 Member Posts: 2,882
    04 HL, 4 cyl, 40K miles, manual temp. controls, A/C blowing air that is barely cool, compressor not cycling on, freon pressure test is good. My wife is the primary driver and describes it kind of like some of the recent posts, works intermittently. I didn't see that anyone had anything conclusive. Any ideas?
  • kenlwkenlw Member Posts: 190
    if the compressor isn't cycling on, the air won't be cool at all. And if the compressor won't come on, how do you tell if the freon pressure is good?
  • mikefm58mikefm58 Member Posts: 2,882
    You're right about the compressor cycling, I must have not heard it correctly. I did notice the temp. control knob was quite loose as others have stated. I pulled the cover off and hand tightened the nut, seems much cooler now, but it's night time, still hot here in Florida but I'll know more tomorrow when it's hot.
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