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Getting an electrical whining noise with cold weather startup coming from climate control. Any ideas.
Normally my car is garage kept but on trips up north (NH) it is outside. I have two issues:
The whining you mention which I attribute to the fan warming up in the cold. Goes away after about 60 seconds. Does not occur if I turn climate control off.
What I believe are air direction controls that will occur 5 or 6 times for about a second each over 60 seconds. Happens whether system is on or not. I had it in the shop once so far and they heard it one day but not the next. They mentioned there are multiple actuators in the dash so no way to determine which one. So am waiting for cold weather and take it in again ( the night before so in the morning they can hear the problem.)
Want to get this resolved under warranty this winter since I am at 38K miles and next year at this time will be over 50K. I own, not a lease.
Blend door motors likely the suspect. This is first year my car is being left out of the garage due to a purchase of a "toy". I have same concern as my 100K extended warranty expires in April so want issue noted when I do my 60K service next month. At least it will be a matter of record.
My sound is like a CD trying to get ejected but no CD in player.
My guess is that the motor noise you're hearing is coming from 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 the pivot arm (forward or reverse) 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 that are 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 a defective unit. I feel sure that some models are a lot more labor intensive to replace than others.
Typically, you will hear the clicking/grinding/clacking noise from a defective servo motor unit during its operation cycle when the temperature is colder or warmer than your vehicle's system is set. Also, 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 its signal voltage to operate the damper door....but there is resistance from something (gears are locked-up, etc.) so you get a whirling, 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...
I've had a similar noise coming from my vehicle's CD player area. I had brought this up to my dealership twice, but they were unable to replicate it - the conditions have to be just right for this to occur (i.e. needs to be cold outside, car needs to sit outside, needs to be a cold start of the vehicle [before vehicle warms up], etc). Being that I'm in TX and my vehicle is mainly garaged, this doesn't happen often. I did recently get this to reoccur and brought to my local dealership. I specified exactly what needs to happen for this problem to show up (i.e. I told them to leave my car outside instead of their inside of their service garage) and they were able to reproduce this problem. My vehicle has only at 36K miles, but since it's been over a year since my warranty expired (model year 2013 GS450h), they could not authorize for a repair under warranty. They wanted to charge $2K+ to replace the entire head unit; no thanks.
I will try to attempt this fix when I have more time to access the stereo unit and disassemble it.
If you are one of the unfortunate individual to experience this noise when it's cold outside (or some people get it when it's warm), then PLEASE call Lexus Corporate at 1-800-255-3987 or e-mail them at support ticket (https://www.lexus.com/contact). Make sure to reference Lexus Corporate Case# 1901112018 - I opened this case up recently with them to make sure they document that this problem is NOT just isolated to one or two individuals, but in fact a problem with their supplied units.
How certain was the technician that the noise was coming from the head unit?
The way you have described the conditions needed to trigger the noise to happen, it seems much more likely that noise is coming from one of the air mix (blend) damper servo motor units.
How certain was the technician that the noise was coming from the head unit?
100% certain. The technicians held my car for several days, opened up my vehicle's head unit, and pinpointed the noise to the cooling fan. All of this without me even mentioning that I have an idea of what the problem could be.
FYI - makes no difference if there is a CD/DVD present in the head unit.
100% certain. The technicians held my car for several days, opened up my vehicle's head unit, and pinpointed the noise to the cooling fan. All of this without me even mentioning that I have an idea of what the problem could be.
FYI - makes no difference if there is a CD/DVD present in the head unit.
~ Im2bz2p345
Yeah he kept saying servo unit in my thread. I narrowed it to the fan by pulling the head unit with the wires connected and turning the car on. There are 2 fans on two sides of the head unit and you could clearly hear one side was clicking. Once I disassembled the head unit I hooked up the defective fan to a power source and it made the same noise 100% confirming the issuie.
Disassembly is not too hard, looks overwhelming, but if you bag the screws and label were it came from, along with taking pictures, putting everything back together was not so bad. Just take your time and you'll be fine. I also hard wired the fan since the plugs are not the same with the aftermarket one.
I have since upgraded to a 2015 head unit and sold the 2013. The 2015 only has one fan because it is sd card based and doesn't need the extra fan to cool a hard drive.
12-20-16 | 10:10 AM
