B1441 & B1443 Air mix damper control servo fault

[Mark Moorhouse]

Hi I own a Lexus NX300h 2015 premier and have developed a fault with the air ventilation system. No air blows out the centre vents and hot air blows out of the passenger side vent even when temperature set to low. 
I have tested via OBD tester and it’s generating fault codes B1441 and B1443. This relates to the air mix damper control servo motor. 
my question is does anyone know where these servos are located in the Lexus NX300h as I just can’t find any information on the web for this model. 
Many thanks in advance. 

[steve2006]

Hi Mark and welcome to the LOC.

Sorry to hear of the problem you are having with your NX.

I assume you no longer have any warranty on the car?

The part you refer “Damper Servo Sub- Assy, Blower No1.” is buried within the heater unit inside the car.

Not sure is access is possible without major dismantling of the dash and heater box.

A known common fault in past Lexus models is damage to the servo actuator arm if not in the correct service position when the pollen filter is replaced.

I hope the attached diagram helps with the part circled in red.

[Mark Moorhouse]

Really appreciate your response Steve, do you think the diagram where you have circled the part is located under the glove box? It’s so difficult to know where that is housed within the dash without the dashboard showing in the same picture. 

[steve2006]

Yes it’s certainly passenger side so removal of the glovebox should give you a better shot at getting to it.

Just be aware of the passenger dash airbag!

[RONNIE W HODGEKINSON]

18 hours ago, Mark Moorhouse said:

Really appreciate your response Steve, do you think the diagram where you have circled the part is located under the glove box? It’s so difficult to know where that is housed within the dash without the dashboard showing in the same picture. 

Would the Haynes Manual be of Great use here.. It would Illustrate the correct procedure on how to replace This Component... Just a Thought.!!!

[Mark Moorhouse]

 

I have managed to remove the glove box which revealed the servo as per above pictures but it’s very difficult to get too as seen. 
I removed the connector and checked for corrosion but all looks ok. 
As this is an intermittent fault I’m not sure if this is truly the part that has failed so reluctant to order a new part. 
I’m reluctantly going to have to take it to Lexus and get them to investigate further. 

Thanks for your help and recommendations much appreciated. 

[RONNIE W HODGEKINSON]

On 12/29/2022 at 3:17 PM, Mark Moorhouse said:

 

I have managed to remove the glove box which revealed the servo as per above pictures but it’s very difficult to get too as seen. 
I removed the connector and checked for corrosion but all looks ok. 
As this is an intermittent fault I’m not sure if this is truly the part that has failed so reluctant to order a new part. 
I’m reluctantly going to have to take it to Lexus and get them to investigate further. 

Thanks for your help and recommendations much appreciated. 

Very Wise... Get your Car To A lexus Dealership who can pinpoint the problem Scientifically...