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Headlight doesn't shut down during power-off & no left signal!

caligula666

Member
Mar 2, 2017
110
80
Switzerland
This morning, I installed 2020.48.35.5. As I went to the car, the left headlight was switched on (parking mode I'd say) even though the car was still closed. I didn't really care as I thought it might just be a post-software-update glitch and moved on.

As I then drove the car, I realized that the left blinker wasn't working anymore: no sound, no blinking-arrow on the dashboard. After testing against a wall, I can see that the led actually blinks but twice as fast. Interestingly, as I put the warning lights, they actually both work, left and right, at the same and correct rhythm (including the left), but only the right blinker appears on the dashboard.

After calling support, I was offered to do a MCU reset, followed by a complete shut down (Controls > Safety & Security > Power Off) and ... all went black BUT the left headlight!!! Yep, even in security power off, the left headlight is still on.

So I scheduled a service meeting but it is only in almost 3 weeks and my car's left headlight is now constantly on...

The only thing I can see is this software update or, possibly, the CCS combo 2 upgrade that took place 5 days ago.

Any thoughts or idea?




(2017 90D, MCU2, AP3, CCS Combo 2)
 

cypho

Member
Dec 20, 2018
765
897
USA
I think hardware failure. Just a coincidence that it happened shortly after software update.

It was actually the update, you would not be the only one complaining of this issue.
 

caligula666

Member
Mar 2, 2017
110
80
Switzerland
That makes sense. What drove me towards a software issue is the über-close concomitance with the update and I then found reports online of people with similar problems after an update and a reboot was typically good enough to fix it. Also, I suspect a bunch of firmware have to be asynchronously updated here and there so this might bring an element of fun randomness that should be managed, but... I might just have to just wait patiently for 3 weeks.
 

caligula666

Member
Mar 2, 2017
110
80
Switzerland
So, I had seen reports of this getting fixed « overnight » somehow and I didn’t quite believe it. See here for example: 2020.48.26 update broke left turn signal

Long story short, this afternoon I go drive my car and: left headlight Is off and left blinking works as expected, at the right rhythm...

So, in all likelihood, *not* a hardware failure, but some software voodoo thing.
 
  • Informative
Reactions: TimT

Dreamontom99

Member
Aug 9, 2017
51
27
Southern Cal
I thought the power off would do that but apparently it required the car to go to sleep I guess

yea me too, I try to shutdown and reboot after every update now as a matter of course. I’ve had several electrical gremlins which were solved by doing so: Seats not working, radio weirdness, turn signal malfunctioning, etc etc.

Really need to treat it like your home computer and reboot if it’s acting weird.
 
May 30, 2018
27
34
Denver
I just had the same thing happen to me! I had my car in for MCU2 upgrade and they said I could upgrade to the latest firmware available (2021.4.10.1) and I went out to check on it and the left headlight was on. Left blinker also doesn't work.
 

caligula666

Member
Mar 2, 2017
110
80
Switzerland
Reboot it and make sure it goes to sleep, so don't go on your application of make sure you are not hooked to an API service (such as TeslaFI) that would prevents it to go to sleep. Once it wakes-up, it should be good.
 
May 30, 2018
27
34
Denver
Reboot it and make sure it goes to sleep, so don't go on your application of make sure you are not hooked to an API service (such as TeslaFI) that would prevents it to go to sleep. Once it wakes-up, it should be good.
I actually opened up a request with Tesla. They told me my car did not take the most recent update (specifically the headlight controller) and they re-pushed the update and asked me to reinstall. Did so and the issue went away.

This makes three times now that 2021.4.10.1 has been installed to my MS. Kinda not trusting their QA process.
 

caligula666

Member
Mar 2, 2017
110
80
Switzerland
I actually opened up a request with Tesla. They told me my car did not take the most recent update (specifically the headlight controller) and they re-pushed the update and asked me to reinstall. Did so and the issue went away.

This makes three times now that 2021.4.10.1 has been installed to my MS. Kinda not trusting their QA process.
Oh, pretty awkward indeed! Glad it is fixed now
 

RobS87

Member
Apr 13, 2018
14
2
Michigan
I just got MCU 2 upgrade on my model s and have very similar behavior now noticed on drive home from service dealer (too bad I picked my car up after hours).
-right blinker does not appear on my cluster display when activating by stalk.(left works fine)
-when activating by stalk right blinker on entire left of car blinks rapidly
- right headlight is not on, neither is DRL.

Can you confirm the fix?
 
May 30, 2018
27
34
Denver
I just got MCU 2 upgrade on my model s and have very similar behavior now noticed on drive home from service dealer (too bad I picked my car up after hours).
-right blinker does not appear on my cluster display when activating by stalk.(left works fine)
-when activating by stalk right blinker on entire left of car blinks rapidly
- right headlight is not on, neither is DRL.

Can you confirm the fix?
Yes. Open a request with mobile service and ask them to check that the headlight controllers took/didn't take the latest software. That was exactly my issue. A re-push of the software and install fixed it.
 

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