GS2013, Vents/AC issue

Reply Subscribe

Thread Tools

Search this Thread

Aug 20, 2019 | 11:54 PM

Fsaadi

Thread Starter

Driver School Candidate

Joined: Aug 2019

Posts: 2

Likes: 0

From: WI

GS2013, Vents/AC issue

I have my gs2013 F sport clean no accident nothing happened to it. my front A/C vents are not blowing at all. When I put my hand in front of them, I can feel a cool sensation (the vent themselves are cold to the touch), but no wind is blowing. However, the rear vents are blowing really well into the back seat.

I went to a technician and did a reset programing it worked for few days and get back to the same issue. after checking the many technicians, they asked my to change some parts but they still not sure after changing the part the car would work. the parts name "SERVO SUB-ASSY, DAMP "

please if you have had the same issue and you know how to solve it please do share

Thank you and waiting your experience with lexus

Aug 21, 2019 | 05:21 AM

Cwang

Instructor

Joined: Sep 2018

Posts: 1,209

Likes: 319

From: NSW

Why not let them change the part they thought was faulty? Have you had the car scanned with Techstream? I would have thought that the damper motors would have self check functionality. Unless you want to go to the effort of scanning it I recommend you have a professional fix it.
You can buy access to the software or acquire it yourself, you will also need a suitable obd2 cable.

Aug 21, 2019 | 09:59 AM

bclexus

Lexus Champion

Joined: Nov 2014

Posts: 13,614

Likes: 2,921

From: Texas

Quote:

Originally Posted by Fsaadi

Your problem is likely (as Lexus has suggested) the air mix (blend) damper servo motor unit. This air mix servo motor unit has a small motor that gets its input signal (voltage) from the vehicle's HVAC system to either open or close a damper door that controls the flow of blended air through the dashboard ducts. Usually an amplifier circuit in the HVAC system controls this servo motor, and uses positive or negative voltage to the little motor to move (forward or reverse) the pivot arm that opens or closes the damper door...based on cabin air parameters, e.g. temperature, humidity, etc.

These servo units are rather delicate and can easily become damaged when one or more of the multiple plastic reducer gears (worm and spur gears) become unmeshed or broken, or the unit's plastic pivot arm that opens/closes the damper door becomes jambed. Most of the time the culprit is the little worm gear that is mounted on the tiny motor's shaft breaks. This problem exists in different car brands and models, not just Lexus/Toyota.

Some DIY owners (with cars out-of-warranty) have elected to try to repair/fix the damaged servo unit - some successfully, and some not. I think the price of a new servo unit is around $150 to $200. I've heard that some labor (only) estimates have been as high as $800 to replace the unit. I feel sure that some models are a lot more labor intensive to replace the unit than others.

Typically, you will hear the clicking/grinding noise when the temperature is colder or warmer than your vehicle's system is set...and when the vehicle's inside temperature comes close to matching the desired temperature (or when the outside temperature matches the desired set point temperature) it will start making the noise - in other words for example, the car's HVAC temperature is set on [say] 72° and the car's inside temperature is (or has become) ~72° and the outside ambient temperature is about the same at ~72° - this is when it reaches the (thermostat) threshold and the servo motor receives signal voltage to operate the damper door....but the gears are locked-up so you get a clicking or grinding sound.

The air mix servo motor unit is located behind the dashboard near the center, beside the duct work that feeds air to the supply outlets.

This is what a typical air mix servo motor unit looks like...