Driver side headlight gets lower and lower

[dasn]

I originally posted this on Reddit but I realised it might make more sense to be here since it might be a AU specific thing:

tl;dr - 2019 RHD M3P driver side headlight level eventually lowers even after intentionally aiming it higher than passenger side one - why?

I've noticed this for a while and I wanted to see if it's just my car.

I have a 2019 Model 3P (RHD in Australia) with non-matrix (original) headlights and basically from the start of ownership (I am original owner) I've noticed that the driver side headlight is aimed lower than the passenger side one. It's not slightly lower, its much much lower, the cars in front will see one headlight brighter than the other (I asked a friend to check).

I thought this might be normal to not blind oncoming traffic. However, I've reviewed the headlight adjustment instructions in the service manual (the one you can access for free from Tesla) and the instructions make it clear that both headlights should be level with each other. So as a result I opened the headlight adjustment setting and moved the driver side headlight up a few notches to be level with the other one.

Fast forward 2-3 weeks and the driver side headlight is visibly lower than the passenger one again. It's easy for me to notice because I drive practically the same route every week and park in the same underground parking spot, which conveniently has horizontal lines on the wall.

As a test, I went ahead and purposely made the driver side headlight much higher than the passenger one. Sure enough, after 3 weeks of driving the driver side headlight is much lower than the other one again. The headlight level doesn't just drop on week 3, throughout the 3 week period I can see it get lower and lower.

This is leading me to two possibilities:

1. The driver side headlight should be this much lower and the car's software has some auto calibration function that eventually lowers it. But this seems counter to what the service manual suggests.
2. OR my driver side headlight is defective, something is loose and over a few weeks of driving the headlight level drops.

I do plan on scheduling a service appointment but would like to see if any others with non-matrix headlights noticing something similar?

Other notes: I am aware that the headlights adjust slightly when you park on an incline and open/close the door, I see this behaviour often on my car and IMO it's a bug. I'm adding this note here to highlight that I think my issue is slightly different and arguably worse.

 

[Hairyman]

I had a problem where both the lights were drifting up.

The service centre got me to put the car on a flat surface and I recalibrate the light elevations. It did it by itself. No problem since.

 

[dasn]

I had a problem where both the lights were drifting up.

The service centre got me to put the car on a flat surface and I recalibrate the light elevations. It did it by itself. No problem since.

I assume you mean entering the headlight adjustment mode and let it do it's initial leveling procedure before it lets you make any adjustments.

If I do that it'll bring the driver side headlight back up to where I previously set it for testing purposes (much higher than the other one). Then over the course of roughly 3 weeks of driving it'll slowly make its way back down again.

I've been observing this behaviour for close to 3 years of ownership now. When I get fed up of seeing my driver side headlight so low I enter headlight adjustment mode and see it bring the headlight level back up again. Rinse and repeat.

I'm starting to think my driver side headlight is defective or someone is moving the lines on the wall .

 

[Hairyman]

Yes, that’s right. Sounds like a trip to the service centre and some specific sorting out.

 

[Onshore]

It is 100% normal in Au cars for the drivers side headlight to shoot lower than the shoulder side.

It’s intentional

 

[cafz]

The driver side headlight should be this much lower and the car's software has some auto calibration function that eventually lowers it. But this seems counter to what the service manual suggests.

I believe this is the case. As @Onshore says, the drivers side headlight is supposed to be aimed lower than the passenger-side one - as you suggest yourself, this is so it doesn't blind oncoming traffic. This asymmetry is noticeable when you see the headlights on a wall.

But you might as well request service check it out to be sure. At least they can properly calibrate them for you.

 

[Onshore]

I believe this is the case. As @Onshore says, the drivers side headlight is supposed to be aimed lower than the passenger-side one - as you suggest yourself, this is so it doesn't blind oncoming traffic. This asymmetry is noticeable when you see the headlights on a wall.

Also worth noting that nearly all modern cars sold in AU (if fitted with advanced self levelling headlights) will display this assymmetry. It's absolutely normal. The idea is to throw the light further on the road shoulder and cast the light lower in the centre of the road so as not to dazzle oncoming drivers.

https://www.cars.com/articles/how-do-i-know-my-headlights-are-aimed-properly-1420683926799/

"You should expect the light pattern to be higher on the passenger side to illuminate road signs and lower on the driver’s side to prevent blinding other drivers. This should give you a good idea of whether the beams on both sides are aimed correctly."

Just like a puddle of water under the parked car when the AC has been running, or surface rust on the brakes and hubs after washing the car. These things are normal and people shouldn't be tying up the finite service capacity with such things.

But you might as well request service check it out to be sure. At least they can properly calibrate them for you.

They may also charge them when no fault is found, though. I think OP should just rerun the 1 minute automatic headlight alignment on the menu in the car, and stop manually raising the drivers side lamp.

 

[bcarp]

It is 100% normal in Au cars for the drivers side headlight to shoot lower than the shoulder side.

I don’t think that’s right. Never seen it before. Both lights are pretty much the same height but the mirrors within each light unit reflects the lights in such a way that each beam is higher on the left than the right. So, cover up a single headlight and you’ll still find the light shining higher up ahead on the left than the right. It’s a function of each individual headlight, not a function of the pair working together. (On the Model Y, it’s the pixels that shine asymmetrically rather than using mirrors.)

 

[dasn]

I don’t think that’s right. Never seen it before. Both lights are pretty much the same height but the mirrors within each light unit reflects the lights in such a way that each beam is higher on the left than the right. [...]

Yes this is my understanding of how it works as well. The beam pattern for each headlight has more light (higher) on the left than the right but the height level of both should be the same.

Also, I should've attached photos to begin with, hopefully this is explains the issue better:

This is what my headlights look like when approx 1.5 car lengths away from a wall [image1]:

The level difference looks worse the further the beam goes, ie. it's even more noticeable on a dark street but I can't photograph that properly.

To better illustrate the issue I've draw red lines on the top edge of each headlights beam, left line is passenger side, right is driver [image2]:

As a test, about 3 weeks ago, I purposely set the driver side (right) one to be visible higher than the passenger side (left) one. Then over the course of the 3 weeks, the driver side headlight level slowly drops and ends up in the position shown in [image2] above.

This is how I believe the headlights should look, they should be more or less level like the blue line [image3]:

Prior to purposely setting the driver (right) headlight higher than the passenger (left) one, when I run the headlight adjustment it would auto level and bring the lights back to a level similar to the blue line shown in [image3]. However, through several weeks of driving I see the driver level side slowly dropping until it ends up like [image1] again.

So I guess my question is, for non-matrix headlight Model 3 owners, do your headlights look like [image3] more or less inline/level? Or like [image2] where the driver side is visibly lower?

 

[Quickst]

My drivers side headlights are lower than passenger side - I think it's excellent

 

[Onshore]

Image 2

 

[dasn]

Awesome thanks for the replies!

It's interesting to discover that it's basically impossible to aim the light too high as it'll eventually re-level itself.

At the same time it's also a little concerning that you don't have complete control over the headlight levels, why have the headlight adjustment option at all?

 

[EVer Hopeful]

What?????

How can this possibly be true?

They make the driver side headlight shine lower than the pax side so it doesn't blind oncoming traffic? I'm sorry but I just can't see this being the case. If it was, then wouldn't the self leveling process set them up like that? Why would it make them equal? And what mechanism slowly 'corrects' that over several days?

Admittedly I've never been to Australia, but in Europe the lenses have (had) prisms built in to throw the light away from oncoming traffic and if you go to the continent with a RHD vehicle, you're supposed to get stickers to cover those prisms up. Used to anyway - I suppose that was when we had bulbs and now we have light units with clear plastic across the front. Still though, this explanation seems really odd. Has the OP got any mates who's cars do the same?


Wait, are we talking regular or main/high beam here?

 

[Zinzilla]

I'd always thought the same thing (or been told), that the drivers' side headlight was aimed lower.

https://pcc.gov.au/uniform/Australian%20Light%20Vehicle%20Standards%20Rules%202015%20-%2022%20March%202019.pdf

Division 2 General requirements for lights
71 Prevention of glare
A light, except a high-beam headlight, fitted to a vehicle must be built and adjusted to provide the necessary amount of light, without dazzling
the driver of another vehicle approaching, or being approached by, the vehicle.

So not explicitly, but implicitly?

And then:

72 Pairs of lights
(1) If lights are required under the Light Vehicle Standards to be fitted to a vehicle in pairs:
(a) a light must be fitted on each side of the longitudinal axis of the vehicle; and
(b) the centre of each light in a pair must be the same distance from the longitudinal axis of the vehicle; and
(c) the centre of each light in a pair must be at the same height above ground level; and
(d) each light in a pair must project approximately the same amount of light of the same colour.

Basically, "lights must be mounted at the same height and distance from the centreline as each other" is how I read that.

So you could say that the idea that the drivers' side light is pointed a bit lower is a consequence of section "71" and not prohibited by section "72".

 

[dasn]

So after many more months of testing I've come to the conclusion that this is a bug or possibly a hardware defect. In Tesla's own service manual it tells you to level them so that both beams are level with each other.

What I've noticed is the following:

1. Have lights leveled as per Tesla's service manual instructions.
2. With headlights on (ie. night time), drive onto an incline (for example on a upward sloping drive way/ramp).
3. Put the vehicle into Park, open and close the driver door, notice the headlight levels change slightly (or just exit the vehicle and close door normally, but it's easier to see the headlights adjusting without exiting).
4. Over the course of a month of driving I inevitably will park on some inclined road/surface at night. Each time I do this and exit the vehicle normally the headlights will change slightly.
5. Do this enough times and the headlights get out of sync with each other and eventually the driver side (RHD) gets lower than the other.

I'm fairly certain the driver headlight is getting lower due to this because for 4 months I purposely did not park on an incline while the headlights were on, and both headlights have remained level. If I had to park on an incline I manually turned the headlights off first.

Once the headlights are out of sync (ie. one is lower), you can enter the headlight adjustment mode and during the auto-level process it brings the lower one back up such that they're level with each other again.

This leads me to believe that something's not right with the way the headlight levels change when you park on an inclined surface. I have no idea why the headlight levels need to be adjusted when I exit the vehicle. If there's a good reason for it then there's some bug where this adjustment is causing one headlight to slowly drift lower and lower.

I have zero hope that this will be fixed, it's such a niche problem that 99.9% of people wont notice and it probably only affects the older style of headlights (non-matrix) which Tesla no longer use.

 

[Quickst]

My drivers side headlights are lower than my passenger headlights. This is normal

 

[Onshore]

My drivers side headlights are lower than my passenger headlights. This is normal

Yep.

Simply typing "driver side headlight lower than passenger" into Google shows the same phenomenon in many modern cars fitted with self levelling headlights. Lexus, BMW, Benz, take your pick. It's normal.

Left Driver Headlight is higher than Passenger side???​

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[dasn]

I honestly don’t know if one headlight is meant to be lower or not but, Tesla’s own service manual tells you to level them such that both headlights are level with each other.

If Tesla intended for one to be lower, why not just include that in their instructions? Why have this self lowering behaviour built into such a weird action of opening/closing the door while parked with the headlights on.

Of course this is all assuming what I’m experiencing is what others are, it’s totally possible my car has some hardware defect.

I’ve basically made peace with this and understand that I’ll probably never know

 

[Quickst]

I honestly don’t know if one headlight is meant to be lower or not but,

This is mine. Its been this ever since I got the car.

It makes sense.
The right side is lowest for on coming traffic on other side of road
The middle is a little higher as no oncoming traffic on the left side of road
The left side points toward the side of the road and should be the highest

I have other more important things to worry about

 

[EVer Hopeful]

If they're meant to be uneven, why doesn't the autoomatic leveling procedure set them this way? Why does it set them level with each other?

and once set, what causes the driver side light to move lower over time?