2016~2023: LED Headlight Vibrating/Shaking

[Edgar_C]

Hi guys, I've tried researching for this issue but can't seem to find the answer. I have a 2017 model with adaptive LED headlight and in the past 12 months or so I have experienced the headlight vibrating/shaking at fast paced when car is in motion or when stopping at stationary in Drive.

This problem only occurs mostly after you have driven the car for a while, it cannot be replicated when car is in Park or Neutral (needs to be engaged in gear and engine is under load). It also cannot be picked up by camera as the vibration is way faster than the camera's refreshed rate.

I've had the problem looked at by Mazda service station but because they cannot replicate the issue since they work during the day in the workshop, you really have to drive it at night to experience it. But they checked the housing and casing of the light unit and can't find anything that is loose or requires tightening.

So I am at loss as to what and how to solve this problem when the service staff can't replicate the problem and I can't show proof in video cause it doesn't get picked up.

 

[Gozo]

Be glad you got 3 years out of it. Just drive during the day. I have a 2020 and it does what I think is the same thing. I brought it in for service and got a “could not duplicate customer complaint” fix. Doesn’t make a bit of difference with the adaptive function on or off.
We have a nice freshly paved piece of interstate that is bump free. When I drive on it, the beam bobbles up around (just up and down, no side to side) as if the bulbs are floating on a bucket of water. Does the same on other roads, but I could blame it on the road surface. I need to take a video and bring it in to the dealer to show them, but without finding why; I doubt there’s much they can do.
Haven’t been doing much driving with the stay at home so it’ll have to wait.

 

[tekz]

Hate to say it but this is typical of LED headlights vs. halogens and HIDs...my last vehicle had adaptive HIDs and never had an issue abt seeing the beams vibrate while on rougher roads. Noticed this with LEDs in both my CX9 and 6. It doesn't bother me anymore as I got used to it but I'd rather get the brighter projection of LEDs than the halogens. A better trade off IMO...

 

[Edgar_C]

Be glad you got 3 years out of it. Just drive during the day. I have a 2020 and it does what I think is the same thing. I brought it in for service and got a “could not duplicate customer complaint” fix. Doesn’t make a bit of difference with the adaptive function on or off.
We have a nice freshly paved piece of interstate that is bump free. When I drive on it, the beam bobbles up around (just up and down, no side to side) as if the bulbs are floating on a bucket of water. Does the same on other roads, but I could blame it on the road surface. I need to take a video and bring it in to the dealer to show them, but without finding why; I doubt there’s much they can do.
Haven’t been doing much driving with the stay at home so it’ll have to wait.

Ok so it's not just me then lol. Yes what you explain is exactly the issue I have, it goes up down, not side to side.

 

[Edgar_C]

Hate to say it but this is typical of LED headlights vs. halogens and HIDs...my last vehicle had adaptive HIDs and never had an issue abt seeing the beams vibrate while on rougher roads. Noticed this with LEDs in both my CX9 and 6. It doesn't bother me anymore as I got used to it but I'd rather get the brighter projection of LEDs than the halogens. A better trade off IMO...

My BMW with adaptive LED have no such issue, nor did my last Merc. This is the first time I've experienced this and it's only for this CX-9.

 

[youri]

There are 2 things other than loose parts that could induce an up/down movement.

The first one would be the auto levelling function of the headlights in the CX-9. This allows the headlight to move up and down depending on the load of the vehicle. I am not sure how it is designed in the CX-9 and how often it engages, but this system could lead to some up and down motion.

The second one is a potential result of projector type combined high/low beam. This is a set-up where the headlight is always fully on and the low beam are created by a a flap that hides the top portion of the light beam (the flap moves out of the way when turning on the high beam, revealing the full beam of light). In some instance that flap can vibrate and results in a vibrating cut off line at low beam. I can't remember if the CX-9 uses that set-up. One way to find out is to stand by your lights when turning the high beam on and off, if you hear a clunk when this happens this is the flap moving in and out of the way.

Note that vibration of the beams is often a lot more apparent with LED and HID headlights compared to halogen because they have a very sharp cut-off (the horizontal line where the low beam stops) compared to halogen lights.

So I am not saying your CX-9 is behaving normally, its hard to know without seeing it, but these are things to note. You could try adjusting the light up or down a little bit, maybe this could settle it for some unknown reasons. https://www.mazdas247.com/forum/ind...e-to-adjust-fog-lights.123870505/post-6675146

 

[Gozo]

Update on the bobbling headlights...

Had a problem with the rubber gasket around both headlights warping and wrinkling significantly. Were replaced under warranty. The service writer didn’t know if the gasket could be replaced separately from the headlights (turns out it can), so they ordered replacement headlight assemblies as well.

The replacement headlights are aimed a bit high for my preference (I’ll adjust them later), but there’s no bobble when driving at all. So it was either the headlights themselves, or how they were mounted.
Either way, problem solved.

 

[11E20]

I own a 2019 CX-9 FWD GT and live on a ranch in remote Texas rural country. There is a 2.3 mile dirt road from my front gate to the asphalt, it is very rough. I do not experience any of the headlight behavior you describe. My two cents on this topic. Best of luck on finding a resolution.

 

[sm1ke]

Update on the bobbling headlights...

Had a problem with the rubber gasket around both headlights warping and wrinkling significantly. Were replaced under warranty. The service writer didn’t know if the gasket could be replaced separately from the headlights (turns out it can), so they ordered replacement headlight assemblies as well.

The replacement headlights are aimed a bit high for my preference (I’ll adjust them later), but there’s no bobble when driving at all. So it was either the headlights themselves, or how they were mounted.
Either way, problem solved.

Any chance you've got a picture of the rubber gasket that needed to be replaced?

 

[Gozo]

Any chance you've got a picture of the rubber gasket that needed to be replaced?

In this thread:
https://www.mazdas247.com/forum/ind...adlight-trim-buckling.123872706/#post-6694453