For a long time I have studied this subject. It's time to say that miracles do not happen. The only way to change Fahrenheit to Celsius, and other parameters from Imperial to Metric - is the reprogramming of 93C66 chips in the dashboard of the car.
Time to restart this thread, it has been a long time since I posted about six years ago about my Canadian 4runner suddenly changing from C to F.
I finally got around to fixing it today when I also replaced the burnt out lights as well, based on garr3ttric3's post.
Thank you very much garr3ttric3 for the information about the third wire. I can confirm, if the white with black strip wire is open the AC unit and outside temp works in Celcius, if you ground the wire the unit works in F.
garr3ttric3 your unit must have been modified after the fact to add the ground wire, opening up the dash on my stock 99 4runner the wiring harness goes into the depth of the dash with no external connection to the screw located between the top vents like your picture shows (page 4 of this thread).
While looking at the AC unit if you disconnect the left connector (seems to control the fan and temp) with the bigger right connector still plugged in, with the key on, you will see the unit in Celcius. Based on that, I plugged both connectors in, had the key on and the unit displaying F again. Taking a big leap of faith, I cut the white with black stripe wire (third wire on the bottom from the left) and immediately the unit switched from F to celcius for outside temp and temp control. Yahoo!
I taped off the ends and wrapped everything back and no more F readings.
Obviously Toyota grounds the wire out somewhere farther in the dash for US models and keeps it open for metric units. Back in 2006 this wire somehow grounded out in my 4runner, and then bugged me for six years by opening up for just long enought to think it fixed itself before grounding out again and displaying F. Oh well at least I understand fahrenheit now.
I'll post if anything weird happens in the next while. Nice to finally get something fixed.
Revival of an old thread! I have a 2000 Ltd 4WD. THIS TRUCK was originally a Canadian vehicle. The climate control was reading in C and not Fahrenheit. I cut the previously mentioned wire and grounded it to the screw in the center of the dash. VOILA ! Now it reads in Fahrenheit but the light bulb on that side of the display does not work. Does the white with black stripe wire have to continue on to the connector after grounding it? Or do you think it's a coincidence that it burnt out around the same time?
I grounded the wire and did not run a lead to the connector, only to the ground screw. Anyone?
I would say coincidence, by the time I got around to fixing the C to F problem all my backlights were burnt out. They do not seat very well and as I recall the connections are not very secure. If you search this forum you will get info on the replacement light part #'s.
A little confused about what wire you grounded, you need to ground the wire coming from the connector which plugs into the AC control unit. Assuming you cut the wire like I did, grounding the wire that goes back into the dash I would think would have no effect.
hey guys, old thread I know but this is my first post and I struggled finding an answer until i stumbled upon this thread so figured i'd leave my experience so future people can try this. I just bought a '99 limited and my display was in celsius. I live in the states so wanted fahrenheit. I grounded out the white wire with the black line as was posted by garr3tricc and it worked for me. My inside and outside temp are now in fahrenheit. SCORE!!!!
I realize this is an old thread but wasn't sure if anyone between now and then could provide any help to me.
I just recently purchased a 2011 4Runner Limited that came from Canada and was able to change all settings to Fahrenheit except for in the AC Control unit, which set to Celsius and is extremely annoying.
I took it to my local Toyota dealer (not who I purchased it from) and they said they couldn't do anything about it and didn't know if changing the body control module would fix the problem or not and recommended I did research myself before trying such a thing.
To say I'm underwhelmed at their knowledge is an understatement.
Any tips or advice is appreciated. I've searched the forums plenty and this thread is the most helpful one I've seen even though it hasn't helped me fix my issue yet.