Heater quit... sort of

[whudson1994]

Same problem with 2003 Highlander. Where are the wires you refer to--are they inside the controller? whudson1994

[whudson1994]

I found the ribbon wire from the pot to the mother board. From the movement of the small circuit board on the bacl of the pot --at least two of the wires are broken. Do I just solder the new wires from the back side of this small board or does this board come loose from the pot? How do I stop the movement of the pot/board---epoxy? whudson1994

[Celtic Cacher]

This place is a life saver. I was quoted $950.00 to replace the environmental control unit at Toyota. I was told that the computer had lost its logic. When I asked about this being a known problem with the Highlander, the service guys told me that they had never heard of any problems at all. After that I did some searching online and so did one of my wife's friends. He put me onto this site and I put all of this information to use today. When I got the panel apart and got to the controls, low and behold, not one, but two of the wires were broken. The nut on the heat control was loose so it fit right in with what had been described here. $7.00 for some 22 gauge wire and some careful soldering later it works like a charm.

[badleedunne]

Another satisfied customer reports that this has solved the heater issue in our 2002 Highlander. Three wires re-soldered and the heat works great.

Thanks for everyone's input.

[StoneyBrookStan]

I'll throw one more success story into the mix. Today I used the information provided in this thread to successfully repair the same two broken leads on a 2002 Highlander. The dealership told us they tried to tighten some nuts that had worked on a previous Highlander they had in, but when that didn't work concluded they simply had to replace the heater control head for $986.00!! I am very grateful to everyone that has contributed. All the information I needed was found here. From the location of the wires to the pictures showing disassembly to the tip on using a spatula to pull the bezel without scratching the dash. Thanks to all.

[roise_r]

wow!... It seems I saved my self 1000+ bucks for typing "toyota highlander AC problem" into google and clicking a couple of times. i didn't have to even type the whole thing, cause google types popular searches for you !! lol ... God bless the internet and God bless this thread
now to bussiness: i just found this thread and unfortunatelly it's too dark ouside to work on the car, but I just want to make sure before I open the thing tomorrow - the loose wires apply to the opposing problem as well, right?... meaning, my AC is hot all the time, even when it's off and i am driving fast on the freeway, STILL hot air blows !

[NJLander]

The heat/cooling is mixed by one of the dials where the problem occurs. I had the same issue after I opened it up, tightened the nuts and didn't find the broken wires the first time. When I opened it back up again and looked at the wires from a different angle, I saw the break.

Originally Posted by roise_r

... meaning, my AC is hot all the time, even when it's off and i am driving fast on the freeway, STILL hot air blows !

[jzack]

Originally Posted by roise_r -- meaning, my AC is hot all the time, even when it's off and i am driving fast on the freeway, STILL hot air blows !

It's hard to say if this is your issue or not? Good news is that taking all the stuff apart isn't real hard - so not like you are wasting loads of time. A few hours on a weekend afternoon is all. Would assume that if you can't control the heat setting (hot to cold or vice versa) with the AC off -- than more than likely it's the issue...

[senator22]

Attached is my step by step experience with fixing my intermittent 2004 Highlander heat. Many thanks to dfluitt and wizzer for the original fix way back when!

I just did this this afternoon. Took a couple of hours, mostly because I went to work to use the soldering iron there which is much better than mine.

Lots of pics on the PDF. Enjoy!

[roise_r]

yeeeahahaha ihuuuuu, ANOTHER success story here, ... count me in !

[tomusa]

Same problem here 04 Highlander. The pictures and all the information were very helpful. I put my laptop in front seat and followed pictures step by step, very good information. No way could i have ever figured this out without help from you guys. I had electronic shop solder 3 new wires for $10. then put nail polish on the threads after installing the nut, works perfect. Saved a chunk of money staying away from the Toyota STEALER.

[liebervj]

You guys are amazing. Count me as another satisfied customer. Heater quick, followed your detailed instructions and back in business.
Greart amazing saved an easy $1000.

I do recommend that we report this Toyota part failure to Toyota as well as NTSB. Maybe Toyota will pay attention if enough of us contact them.

[ILEANL8R]

OMG! I've never even changed oil or touched a circuit board, but I managed to follow the instructions to repair the 3 loose wires and my heater works better than ever!!! THANK YOU SOOO MUCH! The dealership wanted $800. I spent less than $20 for soldering tools and wire.
For anyone that doesn't know much about auto repair or soldering, I can give a little more detailed instructions.
Eileen

[ILEANL8R]

SRS Warning Light Flashing

My SRS Warning Light started flashing the day after my repair job. I probably should have taken it in to the dealership right away, because air bags can be dangerous. However I let it go for about 3-4 days and it seems to have reset itself.

I found out that the Air Bag System can be connected to the radio, especially if the vehicle has a CAN (controller area network). I have a 2002 Toyota highlander. I don't think they started using CANs until 2003, but this still may apply. I also heard that the SRS light can go off if it is disconnected from power. I'm thinking I disconnected the SRS system from the power when I disconnected the radio.

This is a quote from Automotive CAN Network Diagnostics "Various kinds of problems can occur on other CAN-equipped vehicles when the battery is disconnected or goes dead. The modules in the CAN system require a certain amount of voltage for their Keep Alive Memory settings. If this is lost, the module will forget these settings and may not function properly until it has time to relearn the lost data. In some cases, this requires a special relearn procedure using a scan tool because the module can't do the relearn by itself."

[surfshoptom]

I read about 6 pages of this thread and didn't find any reference to Climate Control units that have the Auto Control feature. Our unit works except the Temp knob doesn't function like it used to. You can spin it, but it doesn't change the desired temp. It sounds like it could be caused by a broken wire. Has this been discussed? Is there a link to the discussion? Thanks.