mdony72

Hi Everybody



I have problem on my car (4th Gen GS 450h 2012), I think outside air is coming in even though i have put AC Climate button to AIR RECIRCULATION. It is very inconvenient to smell diesel fumes or other car exhaust gas. especially in heavy traffic.
so I open my glove box and found out that there are two valves on top of cabin air filter. One can open and close as how AIR-RECIR-AUTO-FRESH button is positioned, but the other valve stayed closed. the valve that closed looked normal ( i didn't hear or see if was stucked ) i tried to shift it's opening and it didnt' appear to be loose so i didn't continue 'cos I was afraid if i would rip it instead. Is there Anyone has experience similar situation or knows better on this ?
thank you

Shiloson

Did you finally sort this out? I'm having the same challenge with my 2013 GS350

mdony72

termporary solution,
I duck-tape-ed the Air Inlet hose under the wiper, it completely blocked outside air coming in. For A few weeks it worked just fine, until the other valve also stucked to outside air position.
With both valve stucked, it couldn't sucked internal air for recirculation. I noticed this when suddenly the air flow become very slow. I can stil trick this by keeping the Cabin Air filter a little slided out. so there is room for the blower to suck internal air.
So I think you need to just force the valves to change its direction back to internal air. I didn't do this, cos I m still afraid forcing it will break something,
Let me know if you have other solution

Shiloson

Thanks for the update. I really wish there's more info on how to sort this out permanently while retaining the function.

There's a lot of talk on the 3rd Gen forum of something breaking if the cabin air filter is changed when not set to recirculate. Do you know if this affects 4th Gens also?

mdony72

Seems like This HVAC accesories are common problem to Lexus (and some luxury models of toyta) and also confirmed by the local lexus and toyota dealer , it suprised me, I thought this kind of thing only happend to Mercedes/BMW
the motor that drive this valves are failing, Genuine OEM Lexus 87106-30341 Air Mix Servo Motor Damper Control 8710630341, the error code for this is also shown when i scanned with Techstream.
I don't have enough skill to remove and replace maybe i could but i won't finish a day , maybe I'd just force the valves to its proper position and apply something so it will stay that way. that's my plan

Shiloson

Hello mdony72. Just checking. Did you eventually find a work around?

mdony72

Solved. I had a local toyota mechanic helped me . No part had been replaced. I assumed they just disasembly and re install it again.

Shiloson

Thanks for the response. Did he need to take down the entire dashboard?

mdony72

if u see the picture of those air hose. I dont think it require the whole dash to be removed. I assumend it would only be The glove compartment and a few other part to reach that hoses

Mives

At which toyota authorized / workshop did you fix it? Would be great if the same mechanic could fix the same issue on my car.

My 4th gen 2012 GS350 is having the same issue where only one of the two dampers are controllable - went to the nearest toyota authorized and they only helped me to temporarily fix the problem by duct taping a piece of cardboard above the dampers.

Pierregirard

That issue you're having could have something to do with one of those little doors (flaps) you noticed in the glove box area, right above the cabin air filter. Basically, these flaps are supposed to decide whether to let fresh air in from outside or just keep the air already inside circulating.

mdony72

Initially I did the the Duct Tape, but it's WRONG, because the duct tape will be blocking the Air Flow, to put them in the correct way should not be difficult, it didn't require you dis-assembly the whole dash. you just need to instruct the mechanic to try it. just remove the console box and some additional part i guessed.

bclexus

HERE is the Lexus TSB for the HVAC Servo Motor Malfunction problem.

A Lexus service department can flash reprogram the air conditioning amplifier assembly, which often fixes the problem. But it should be noted that the air conditioning amplifier flash reprogram is only performed ONE TIME if the air conditioning amplifier has NOT been flash reprogrammed previously.

The Lexus tech should follow the procedure exactly as outlined in Service Bulletin L-SB-0001-18 'Techstream ECU Flash Reprogramming Procedure' and flash the air conditioning amplifier with the NEW calibration file update.

Mives

Yup I know - that is why I said I have the same problem as the OP

Agree - the duct tape was the temporary measure suggested by the Toyota authorized nearby (Auto 2000) as well but to be honest it did not really solve the problem, outside air still enters through the gap - you know how bad the diesel fumes from the trucks in Indonesia can be. They don't want to fiddle with the console box / dashboard and asked me to go to Lexus authorized instead.
As the service queue was too long (as you know we only have 3 Lexus authorized in the whole country), I opted to go to a 3rd party workshop and they got rid of the duct tape and cardboard that Toyota authorized applied, and used damp membrane kit + sealant instead. It works wonders honestly - I don't need fresh air circulation since there is no "fresh air" in Urban Jakarta Metro area.

Thanks for this - I also came across the same document when doing my own research. When doing my regular maintenance, I brought it to the Lexus authorized to show them this document and they said that reprogramming and cleaning would still need disassembly of the dashboard and it's not guaranteed fix. They suggested since I have solved it with the damp membrane kit + sealant, to just keep it going as it's working very nicely for me and I don't have to waste $$ for the service fee required for disassembly and possibly requiring to replace servo + amplifier.

mdony72

That 3 Lexus Dealers are just for oil changes and regular minor maintenance ( that i also have stopped visiting as they only provide two kinds of oil 5W40 and 0w20, i prefered 5w30), you need to go to the main workshop at sunter but you have be refered by these dealers. But The experience at Dealer shop is very entertaining , during the pandemic i didn't mind siting the whole day and worked from there.
>and used damp membrane kit + sealant instead.
not sure what you meant, but i think the right way to correct the two valves to point in in the right direction, also not sure also if for your case, both valves are stucked or just one. if ever both are stucked, sealing the air hose will block the overall air flow. if only one stucked, you will still have enough air flow from the cabin
and At some I point if you want to keep the car you need to replace the whole HVAC assembly brand new
when it get worse you won't get any air blowing at all, as there are more than 5 motor servos, , the one control the recirculation is just one of them.
I never dare to touch any climate button anymore except the fan speed check this video :
>I brought it to the Lexus authorized to show them this document
i didn't bother presenting it to them, I ve guesed how would they respond.