Beginner guidecomma fourcomma 3X
Mount it, drive a few minutes so it calibrates, then engage with your cruise button. Here is what the screen means along the way.
First few minutes
openpilot learns how the device is angled. Until then it will not engage.
The screen says Calibrating with a percentage. Only straight driving above 15 mph, about 24 km/h, counts.
About 25 seconds of straight, steady driving is enough. The time need not be in one go.
Turn on cruise control as usual. openpilot takes over after a sound, and the screen changes colour.
The device must point straight ahead and sit level. Move the mount to the centre and try again.
Reading the screen
The two devices show the same information in different ways.
Changing lanes
Below that speed openpilot will not change lanes for you.
openpilot cannot see beside you. You confirm the lane is clear.
The screen says Steer Left or Steer Right to Start Lane Change Once Safe. A small nudge starts it.
Cancelling the signal stops the move. If nothing happens within ten seconds, it gives up.
Driver monitoring
The camera above the screen watches your eyes. You never need to touch the wheel to prove attention.
The face icon turns orange as soon as a countdown starts and green again when you look back. Three ignored warnings lock openpilot out until you restart the car.
Two modes
openpilot starts in chill mode. Learn that first.
openpilot steers. Speed follows your set speed and the car ahead, or your car's own cruise on some models. The path on screen is green when it may speed up.
The driving model controls gas and brakes and can stop for lights and stop signs. comma calls it alpha and expects mistakes, so keep your foot ready.
Common messages
The car stopped and will not creep on its own. Tap resume on the wheel.
The bend is sharper than openpilot can steer. Steer through it yourself.
Your car's steering only helps above that speed. It is a car limit, not a fault.
openpilot refuses to engage until the car is ready to drive.
The car's own emergency braking is warning. Brake now.
Quick answers
Usually a few minutes of normal driving. It only counts straight driving above 15 mph, so town traffic takes longer.
Green means engaged. On the comma 3X the border turns green; on the comma four the two nearest lane lines turn green.
The driver camera saw you look away. Warnings escalate after roughly 3, 5, and 11 seconds, then openpilot disengages.
On most listed cars, yes. On the others the screen says Press Resume to Exit Standstill and you tap resume.
Not on day one. Chill mode is the default. Experimental lets the model control speed and stop for lights, and comma calls it alpha.
Speeds, timings, and message text come from openpilot 0.11.1 at one checked version, the release branch for both comma four and comma 3X on September 11, 2026. Screen colours come from the same code and comma's launch posts.
Car Unrecognized has its own fix. Setup and community guides cover the rest.
Photos: comma.ai. CommaGuide is an independent guide and is not affiliated with comma.ai.
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