Taillights not working (software) in Auto

[JulienW]

Oddly this ALSO happened a little over a year ago when my 3 was new and was perplexing. People flashing lights behind me so pulled over and put in P. Got out and no taillights. Was confused since Teslas are not like regular cars and wondered if they went off as I got out. Reset MCU and still the same. Turned lights on manually and they came on. After an update (I think) they started working correctly again.

Just got 32.3 last week (coincidence???) and first drive in the dark and it is happing again. Odd that it is something software, since in manual they work, happening again after a year and never saw a thread about it happening to others. Guess I’ll wait on 36.x and see what happens.

Anyone else are any ideas or suggestions (have tried reset)?

Auto

Manually turned on

 

[Phlier]

When your tail lights aren't working in Auto mode, does your car's avatar on screen show that they are on?

The actual state of your car's head and tail lights (including brake lights) are shown on the car's avatar on screen. A mis-match here might tell us something... what? I'm not sure, but something.

 

[JulienW]

Yes, the icon is illuminated. Also you can see in my 1st pic the headlights are On and the taillights are Off.

 

[Phlier]

Off the top of my head, I would suspect a relay is going out on you. Where that relay would be located in the car, I have no idea. But it should be something easily found and checked.

 

[ItsNotAboutTheMoney]

That's like Auto is behaving like the headlights are DRLs.

Just rear lights?
Brake lights working normally?
Light sensor issue?
Anyway, contact Tesla. They might care enough to get a quick fix out.

 

[JulienW]

That's like Auto is behaving like the headlights are DRLs.

Just rear lights?
Brake lights working normally?
Light sensor issue?
Anyway, contact Tesla. They might care enough to get a quick fix out.

Unless my memory is slipping (and could be) we have the strip below the normal headlight for DRLs (see pic).

Just the rear taillights and ONLY in Auto. Switch to Manual and they come ON so it is not hardware
Brake lights works normally
Light sensor works normally

 

[john5520]

I'd take it in for service before updating again since it's happening now and easier to diagnose.

 

[camalaio]

It'l be a bit before I can report back with my car's behaviour concretely, but I'm pretty sure my tail lights turn off when I step out of the car in the dark. On definitely does force them on though.

They could've been flashing you for some other reason, or maybe that day you accidentally had them set to Off manually (I've done this when parked somewhere and turned them off waiting for someone, for example - Auto doesn't go back on by itself necessarily).

 

[TX_M3P+]

I'd be more concerned what the car does when in D than in P. I believe there are additional setting that allow the headlights to say one once you park the car and this may be why you have headlights with no tail lights in P. Get a 2nd person to confirm what happens when the car is in D. If you don't have tail lights when driving, then that is a much bigger issue and should be fixed by Tesla under warranty.

 

[AltLogic]

Driving home early this morning and two cars passed me then slowed down to get behind me then passed me. I double checked that my lights were in auto mode and the in car display (screen) had them illuminated. I thought about this post and backed into my garage to check my tail lights. I backed in and verified that the reverse and brake lights worked. Then I put it in drive and I couldn’t see any red reflecting off the white wall. Flashers worked and also when I put it in park the tail lights were dark. I’m on 2020.32.3.

 

[Gasaraki]

Unless my memory is slipping (and could be) we have the strip below the normal headlight for DRLs (see pic).

Just the rear taillights and ONLY in Auto. Switch to Manual and they come ON so it is not hardware
Brake lights works normally
Light sensor works normally

View attachment 585361

DRL is the top strip, not the bottom one.

 

[RichardB123]

A bug. I park, and turn the exterior lights off, then when I start driving again the headlights automatically switch to auto. The headlights come on, but taillights do not. The work around is remembering to manually turn the exterior lights on, after turning them off. I can switch to "on" or "Auto" - both will result in taillights working.

 

[HAL2001]

Are you changing the setting on your Easy Entry profile and not your driving profile? Changes are saved to the active profile And if you parked your active profile is easy entry.