My 2015 IS 250 is in the shop today for this same reason. The climate control doesn't control very well. It's almost like it has a mind of its own. You can go hot or cold. Dual on or off. And it will normally blow hot air out the front vents. And cold out of the rear seat center console vent. ReInitialize the system and it will go cold and stay there till you select hot or turn off the car. So far Lexus has changed the 2 servo valves. With no luck. And is waiting for the two temp doors to come in.

 

Temp doors fixed my problem.

 

Don't want to jinx it, but the temp doors are not going to fix the problem. This is a prevalent problem developing with IS vehicles. When they replace the temp door, they re-initialize the system. The re-initialization only has reset the problem, and could have been done without replacing the temp door. Currently Lexus has in the works a hot fix for this concern. That means they are currently collecting data and engineers are working on developing a more permanent fix in the form of a Technical Service Bulletin. Maybe your dealer doesn't have experience with it, but that will change over the next few months.

 

They tried reinitializing 3 time on my car. It would go back to cold. But as soon as you moved the temp to hot. Or turned off the car. It would then again never go back to cold.

Lexus swapped out the servo valves first. And that didn't work. Then the two temp doors. Since then it has worked correctly. The last time they had the car for almost 20 days. When I picked up the car last week. It had about 3/4 of an inch of white engineering notes with it. So hopefully that got more information about this problem.

And if if it come comes back that's fine. I love driving a new GS and making payments on a used IS.

 

Bump because this happened this morning on my 2019 IS 300 F Sport, build date 09.18 with 9,100 miles on the odometer.

Was really surprised to see a potential failure this quickly on a 2019 Lexus. Hopefully this isn’t a trend. This is one of the big reasons I lease before I pay the vehicle off post-lease.

Anyone else have this issue? I’ll update what the repairs were once I get it back.

 

Kind of disheartening to see such an issue on a 2019 Lexus. I'm not sure if this is on the 3IS long term reliability list but if not i should probably add it.

Part of the appeal of a Lexus is your ability to trust it, and the ability to trust it won't cost a ton of money (or time) to fix normal every day things that shouldn't be breaking, after the warranty expires. Cars in general are getting more complicated though.

 

Welp... it’s a driver side servo. Got the text with the diagnosis tonight. They claim it will be repaired tomorrow afternoon

 

Add me to the victim list. 2018 IS350. (I purchased new). Driving in pounding rain, windshield fogged up. I turned the defrost on and when I changed back to chest level, only hot air. No A/C. Dealer reinitialized the servos.

I've been afraid to use the defrost because it's our uber hot season here in FL. Hopefully a TSB will materialize soon...

 

For reference, Newport a Lexus replaced 87106-30610 on my car. Not sure how much they had to pull apart but thankfully everything looks exactly as it was when I dropped it off. No scratches or scuffs.

 

Just had the exact same issue as above this morning. Used my defrosters during a small spell of rain we had here last night. Drive from San Diego to Los Angeles with the drivers side chest level vents blowing scorching hot, and the passenger side ice cold. Meanwhile, my driver's side footwell was ice cold and my passenger's side footwell was scorching hot.

Turned off the car after I got to LA, restarted it about 15 mins later and all was normal again.

 

Bringing this thread back from the dead. This same issue happened this morning on my IS again - passenger side blazing hot, driver's side cold (AC running) for all modes. Tried turning off the car, waiting an hour for any blend doors etc. to reset, still was blowing uneven temps.

Went into the glovebox and pulled out the cabin filter to reseat (making sure the system was in recirc first) and this fixed the issue!

 

@m0chafrap There is a Customer Support Campaign out now to resolve this issue...it just launched. Also setting it to Recirc is only a requirement for 2IS...you don't need to do that on 3IS.
I suggest inquiring with your local Lexus dealer for the permanent fix...I suspect it was only coincidence that the system started working normally after you removed/installed the cabin filter.