How long after the reset did the problem start again?

 

Here's my history regarding servo maintenance:

09/18/18 - Purchased new.
09/13/19 - Driver's side not cooling. Servo Recalibration.
10/30/19 - Passenger side blowing hot. Replaced servo #6.
11/15/20 - Center vents blowing hot. Recalibration.
11/21/22 - Air not blowing through dash vents. Greased and pulse cleaned servo motors.
03/25/24 - Passenger vent blowing warm. Replaced servo #6.

 

Thanks Chinee,
Did the recalibration for the center vents fix the problem or did the center vents eventually go bad again as well?
Rob

 

Recalibration fixed the issue, but in 2024, the passenger vent I referred to was the passenger side center vent. So yes, it did fix the problem, but it eventually did fail again.

 

Thanks Chinee.....appreciate the reply. Lexus offered me a steep discount to replace the bad servo ($800......down from 3k) but since the update it's been running fine and I'm not sure if I should get it fixed or keep my fingers crossed and hope the update will fix the problem.

 

My 16 GSF w/ 70K miles had 2 bad servo motors & wouldn’t blow any air inside cabin except windshield defrost & rear vents. Carista showed B1443.

Long story short, I purchased Kornerstone warranty when I purchase car & this is the 3rd claim I filed. The costs of the 3 claims paid, exceeds what I paid for the warranty by over $1,000 w/ 18 months/20K miles remaining!

Everyone says, it’s a Toyota/Lexus nothing will ever go wrong w/ them. Yeah, the motors are bulletproof, but there’s so many other wear n tear items. For ME, it’s been a blessing.

Im not affiliated with Kornerstone. Just my testimonial of saving over $3,000 yesterday at Lexus!

 

Yes I experienced similar to your situation. I still have a Platinum extended Service contract from Assurant Protectant care, on my 13 GS350 for 2+ more years and up to 140k now at 56k. I had a Starter installed, 2 outside mirror motors fixed, 4 new Struts covered and a few other things to about $4k plus so far. I paid $1700 for it some years back.

I have owned the GS350 for some years now and after I paid for it I went back to my credit union borrowed $5k on it just to apply the service contract and gave them the $5k right back. I only mention this as a idea to help others that may be able to do the same. I heard this the other day on a tv ad saying, it's car sooner or later some things will break.

 

Here we go AGAIN! First cool front of the season and turned the heat on. Now the driver side and driver side center vent are stuck on hot. Not sure what my next course of action will be… other than to take a chill pill and contemplate this issue tomorrow.

At 71k miles, this is not what I expected. ☹️

 

New to the forum, from Canada because of the servo motor issue.
Mine is a 2021 lexus is300awd, only at 28000 km.

Is thera a way to make this issue heard more and to have another TSB or customer program...

 

Dang looks like I'm now in the same boat. The passenger side AC is blowing warm air on mine now. I tried reinitializing (I still have old firmware) multiple times but this servo doesn't move lower than 256. It's not fully hot air, so mine likely broke partially open.

My front defrost and now my rear blower servo sometimes throw codes, but you can at least see the values change and things operate fine after reinitializing.

With any luck, the "Cool air mix" may be reachable without full disassembly.

 

Same happened to mine. Cars been at Lexus for the last week while waiting for the motors to arrive. Only 3 months ago I had 3 that went bad. Now it’s 2 that control the 2 passenger side upper vents.

luckily my 3rd party warranty is still valid (THANK GOD!), as we all know these are not cheap!

Has only cost me $100 for each claim.

 

Took a stab. No real success other than skinning my finger

In my case, I was trying to remove the "Cool A/M Servo (P)". This the the servo that moved when commanding the passenger cool air mix. It almost seems like the door is getting jammed since you can feel the servo almost flex trying to reach a lower value (in Actuation testing). Below is a look with the glovebox removed:


You can remove the connector with some long needle nose and a small flat head to pry. Then you can slowly loosen the screw circled in green with a right angle ratcheting screwdriver. Watch out for the ground crimp in red. It's sharp enough to skin you hand


Looking at page 55 of 77 of the TSB, you can see the servo has two screws that need removal. The one above and another that I can't currently reach.



I'll poke at it more later...

I wish there was a way to remove the blower unit as that is fully in the way.

 

You're almost there, the blower housing is held by three 10mm nuts/bolts. Undo a few plugs and you'll gain better access to the servos

 

Nice. I saw the right two but didn't see that left one. I'll give that a try.

My new servo comes on Saturday but I'll try to get the "bad" one out to see what broken inside. For the other servos that aren't fully bad, I have a feeling it is this issue since the actual values are almost matching the target pulse values. I bet the worm gear is loose, not allowing the motor to quite reach the desired value.

 

Well I like to struggle, so I went ahead and tried to take off the cool air/mix passenger side servo for B1454 error code. I was able to do it without removing the blower unit, just to see if it could be done. But if I have to do it again, I'll try taking off to compare effort.

I basically followed the steps in the IS dealer video. You remove the glove box and lower knee pad airbag panel. You also remove the black foot vent (held by a Philips) and unplug and move out of the way the AC amplifier (also held by a single black Philips). Also unplug the two thick wire gauge (creme and black) plugs.

I had initially struggled with the harbor freight right angle screw driver. I got this with more teeth and less backdrag since you don't have much room to turn.

Also, I used the 1" and 2" Philips from here: It doesn't have to be that set, just something that has a 1" and 2" bit. The DeWalt bit set I have only has 1" and 2.5", which is too long. It'll be easier if you cut down one of the 2" bits, like this, so it's the perfect size.

Lastly, I also used one of those snake cameras to help guide for the back screw.


Either way, I popped open the servo (just some tabs). There weren't any missing teeth as I thought there might be. I took out the wiring pin and potentiometer assembly and took off the cover (4 flexible metal legs). I cleaned with with parts cleaner.




I put the potentiometer back together, and added lithium grease to the gears and pin points.


I put it back together and back in the car and did an initialization. And... still and error initially. It was still getting stuck.

What eventually got it going was setting passenger temp high, then doing an initialization. Then setting temp around 72, and doing another initialization. Then setting temp to LO and doing another initialization. You check the values between initializations, as you change the temp. Say you set a temp, and you see the "command" at 158, but the actually value only goes down to 192. So you'd leave it at that temp, then do an initialization. Repeat as needed.

Eventually, it was able to do all the range. I do the a new part coming in over the weekend, but I'll go with this one until it breaks. I'll have to take out and clean/regrease others when I have time as I'm getting other intermittent errors, like rear servo (B1449), B1443, B1446, B1442.