Richard-W

As an aside to all discussions on this problem here, I went through a particularly nasty pothole and the fault instantly corrected itself. There must have been a loose wire/connection somewhere and the jolt must have corrected it.

Is it possible you could send me a copy of the email confirming Lexus will fix this under the 10 year 100,000 mile warranty?

Lexus Warranty was 5 years 100,000 miles when I got the car so it expired in 2019. Toyota & Lexus now offer a 10 year, 100,000 mile warranty which was introduced in, I think 2021. Perhaps someone else can confirm this.

87106-30500 is the part number I have. In British market right hand drive cars it is located behind the instrument panel which means the dashboard needs to be removed to get to it. On European left hand drive, it may be possible to get to it by removing the glove box. I don't have the capability to remove the dashboard and was quoted over £2,300 to fit it.

That happens because the control panel is not getting the correct signal back from the servo motor. It also affects the switches for the heated seats.

I have done more research on this and the control panel is not the problem. With the assistance of Lexus Parts Direct, I have got the illustration of the heater unit. It appears the fault is caused by the Denso made Heater Mode Servo Motor - Part Number 87106-30500 failing. The green box on the picture below shows where it is located. On left hand drive cars it might be possible to access it by removing the glove box. On right hand drive it looks like taking out the dashboard is the answer to getting to it's location just behind the instrument panel. It is a fairly problem with all Toyota and Lexus cars with digital air conditioning controls and Denso Servo motors. The little worm drive for the internal gears is what fails. A you tube video shows the similar part being replaced on an American Lexus GS

Hi, 2 years after I bought the car Lexus introduced a 10 year 100,000 mile warranty option, unfortunately I it could not buy in as the previous warranty expired.

See post above

So the inspired fix above didn't work, there is something called a Heater Mode Servo Motor that changes the position of the direction flaps in the ventilation. It is buried behind the dashboard on the driver's side in RHD Cars and at the very least the centre console needs to be removed to get to it. Heater and Air Con otherwise working ok and sending air through footwells and dash vents as it should. Until I can get it fixed, I have invested in a 12 Volt 150W dash mounted fan that plugs in the cigarette lighter socket. Not ideal. but it goes some way to alleviating the problem. £16.99 from Amazon dashboard.jog

Left hand picture shows part of map screen that is where you can change the display (Emerson Lake & Palmer track playing gives my age away!) Right hand picture shows heater controls on centre screen.

I had a flash of inspiration on this and changed one of the displays on the sat nav home screen to show the HVAC controls. (The option key is in the very top right of maps, I will post a picture here when my wife returns with the car.) The controls behind the gear-lever remain faulty but all settings can be changed by the joystick and everything works as it should.

I have the same issue, it was -6 centigrade this morning so pre-heated the car with a domestic 2kW portable fan heater (£11.99 from Screwfix) this morning while I sat in the house with a cup of tea. Not ideal, but solves the defrost problem on really cold days ...

I got one from a local independent accessory shop for £55, it's the same as, I think, a Toyota Aygo 12V battery.

Thanks for the replies, it appears to be a fairly common and minor issue. There was a different minor fault on the unit a few months ago that went away on its own, I will wait and see if it gets worse.

I have a 2014 IS300h with 70,000 miles and a fault on the air con control panel on start up. There is power to the panel as airbag and seat belt lights come on, but the air con controls take about 20 seconds or 200 yards driving for the full display to come on so adjustments can be made and then works fine. I had the system re-gassed last service. Has anyone else experienced the same problem?