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Left headlight always on after update

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Got MCU2 and FSD computer installed.

After returning home, there was an update (2020.20.12) waiting to install, so I did it.

After the update, my left front headlight was permanently on. The left turn signal was also not operating correctly - it was blinking fast and had no sound or dash indication.

Rebooting did nothing.

Trying to contact Tesla, but that has its own problems.

Any hints on what to try? Was going to try and pull fuse on headlights to see if that would reset things.
 
I had the exact same problem after installing 2020.44.15 on my 2017 Model S.

The left light stayed on after the car had been parked and the left blinker blinked twice as fast and made no sound. The blinking green arrow on the dashboard was also missing. The right blinker worked perfectly normal, with sound and blinking green arrow displaying on the dashboard.

Tried rebooting a couple of times, with brake pedal pressed. Did not work. Left the car parked for an hour, the problems stayed.

Was about to call tesla service but googled and found your description and decided to just let the car be over the night and this morning the problems were gone. So thanks for saving me a service visit!

Can add that I also had a MCU2/FSD upgrade, but that was over a month ago and I had several software updates since without problems, but maybe this is a rare edge case that sometimes happens to this particular config.
 
Same here. 2017 MS, that had new MCU2/FSD put in about 6 months ago. No issues (that I know of) since, but just had a software update (Jan-2021) and left front headlight on for about an hour now. Based on your helpful posts, I imagine it’ll turn off in a few hours.
 
I had MCU2 retrofit on my MS 2016 (AP1 facelift) last week and installed my first OTA update yesterday. Had exactly the same symptoms- after trying all restarts etc I ended up having to put a trash can in front of the left headlight to stop it illuminating my neighbours house all night! After reading this, I relaxed and waited until morning - magically fixed!

For those with this issue, don’t panic- just wait it out!
 
It’s still a problem that Tesla just can’t fix. After the current software update my left headlight stays on and the left turn signal has no blinking sound and it flashes rapidly. This is the first time this has happened after owning my car since 2016.