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MCU2 + HW3 Stop Light Control (UK)


Jul 3, 2021
Hi, I recently learned that upgrading my AP2.0 and MCU1 tesla model x to MCU2 will also give it HW3 btw I am in the UK

I am aware that having this upgrade means that the car CAN SEE traffic lights and stop signs

however if I DO NOT purchase the FULL SELF DRIVING package will it still stop at a red light? Or will it literally see the red light and go straight past it.
I would think that’s kind of stupid for a car to do if it was that smart in the first place so please can someone let me know.



Active Member
Jul 1, 2019
mid wales
It'd mean that even if FSD was not activated it'd stop at the lights..which it'll do with FSD whatever colour they are unless you override the greens with throttle.

Fursty Ferret

Jun 13, 2021
I believe in the USA the car will apply emergency braking to prevent you running a red light at speed regardless of whether you have FSD or not. Difficult one to test though...

Pink Duck

Jan 28, 2020
South Norfolk, UK
Also after a while you end up feeling like you're repeatedly training the system to recognise traffic light controls, where the frequency of hesitant moments doesn't appear to reduce after many months.

It seems like all effort is focused at present is on FSD Beta 9.2 for the US.

Plus at present I find my own progressive regen/braking to be superior to that of the auto-stop on red lights.

Until junction and roundabout handling you'll also often find disabling AP results in the stopping force necessary before driving those manoeuvres yourself anyway.


Active Member
Feb 24, 2020
I have FSD. On mine, traffic light stops works on TACC alone as well as AP. It’s a bit pointless. It stops too far from the line.
in addition, if you are turning left or right, TACC moves off too fast to corner properly and AP won’t make a turn anyway.

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