What actually are the signature lights and how to tell if they're working

[sjkjs]

I've done a lot of reading and looked at photos and videos but it's still not clear to me what the signature lights actually are.

At first I was under the impression that it was the big textured strip between the main headlight and the indicator/turn signal, but now I'm wondering if it's actually a component of the DRL at the top of the light.

Is my signature light working in this photo? If yes, how can you tell? If no, what should it look like if it was working? All I can see is one light, the regular DRL.

 

[E90alex]

The green strip is the signature light and the blue is the DRL/parking light.

Even though Tesla considers them two different lights, I’ve only seen them come on together. So functionally (and visually) you can just consider it all the DRL.

 

[sjkjs]

Thanks. Are there any good close up photos of how a working signature light should look? I can see light coming from mine but it seems like the LEDs are set back a fair way from the plastic diffuser which makes it hard to actually see. Is this the problem people talk about where the glue fails or something and it falls out of place?

If this is how they're meant to be then that's fine, but if it's got a problem and needs replacement then I want to know what I'm talking about before I open a service request (I can imagine them turning me away otherwise).

 

[E90alex]

It’s a fiber optic light tube fed by LEDs at the top corner of the headlight.