comma three

Installation Guide

7 steps
30 min
comma three devkit
from $1499
  • comma three devkit
  • right-angle OBD-C cable (1.5 ft)
  • 2 mounts
car harness
  • car harness (harness box & connector)
  • comma power
  • RJ45 cable (7 ft)
CAN FD Parts (Not needed for most cars):
Most newer Hyundai, Kia, and Genesis models are equipped with the CAN FD communications protocol. The red panda allows the comma three devkit to communicate with your car over this protocol. Check compatibility to see if your car requires CAN FD parts.
CAN FD panda kit
  • 1 red panda
  • 1 harness box
  • 1 USB A-A cable
  • 1 USB C OTG cable
  • 1 OBD-C cable (1.5 ft)
Note: Nissan & GM Setup
See more setup details: Nissan or GM.
Step 1 of 7
Remove the rearview mirror cover trim
Removal method varies by car. The durable plastic often requires a strong tug to pop it off on Hondas. Toyotas often need a slide outward. If you’d like to see how it’s done, find a comma installation guide for your specific make on YouTube.
Step 2 of 7
Connect car harness into the camera
  • Unplug the existing LKAS camera connector and plug it into the harness.
  • Connect the other end of the harness back into the LKAS camera.
  • Secure harness – Find where to place the harness box so the trim can still be installed over it. Peel off adhesive sticker and attach the harness in place.
  • Use the extra OBD-C cable to plug the red panda into the harness box connected to the LKAS camera harness.
  • Connect one side of the USB-A to USB-A cable to the red panda, and the other to the USB-A to USB-C OTG dongle.
  • Connect the USB-A to USB-C OTG dongle to the auxiliary port on the comma three (port near the bottom).
Step 3 of 7
Plug the RJ45 cable into the harness box
  • Plug the RJ45 cable into the harness box – ensure the cable is fully seated.
  • Plug the RJ45 cable into the second harness box (not connected to the LKAS connector) – ensure the cable is fully seated.
  • The RJ45 cable must be brought across your car to your OBD-II port which is almost always found below the steering wheel to the left. Carefully run the cable behind the vehicle trim along the windshield, doorframe, or dash.
  • Plug the RJ45 cable into the comma power and then plug the comma power into the OBD-II port.
Step 4 of 7
Place mount high and centered on the windshield
  • Positioning – Ensure the top of the mount is fully visible from the driver's seat.
  • Mounting prep – Clean the mounting area with the included alcohol wipe and let it dry.
  • Adhere mount – Peel off the 3M tape on the mount. Press firmly in the center of the mount, then the edges. Ensure no bubbles form.
  • Let the mount cure – The mount must cure for 48 hours before installing the comma device. Skipping this step will compromise the integrity of the mount.
Step 5 of 7
Plug in OBD-C and mount the device
  • Plug the right-angle OBD-C cable into the harness box – Ensure the cable is fully seated. For comma three, ensure the straight end is connected to the harness box.
  • Clean all three lenses with the included microfiber cloth.
  • Plug in OBD-C and mount the device – Plug the OBD-C cable into the back of the comma device. Make sure the cable is all the way in.
Step 6 of 7
Pair your device with comma connect
    Pair your device and claim 1 free month of comma prime with on your phone.
    Step 7 of 7
    Reinstall the rearview mirror cover trim
    • Ensure the car harness fully fits inside the trim. Have the OBD-C cable come out of the top.
    Frequently Asked Questions

    How and where do I buy a comma device?

    The comma shop is the only official retailer of comma devices (the comma two and comma three). The comma shop accepts all major credit cards. We offer free shipping in the U.S. and $30 flat rate international shipping.

    Buy the comma three here.

    I ordered a comma device! Now what?

    Congratulations! Get started by watching the Installation Guide on our setup page. We find on average the installation process takes 15-30 minutes.

    If you encounter an issue, we recommend you join our Discord community where hundreds of active users are available to help troubleshoot.

    For updates on shipping dates, join the comma-shipping channel on Discord. Orders are fulfilled on Monday and Thursday. You can cancel your order for a full refund up until it ships by emailing

    Does installing a comma device require permanent modifications to the car?

    Installing a comma device does not require any permanent modifications to your car. With the car harness, most car trims remain in place.

    How do I mount my comma device?

    Watch our Mounting Guide. First, figure out where on the windshield you would like to mount the device. We recommend it be centered on the windshield below the trim. Be sure to leave enough room to remove the trim in the future. Clean the windshield before mounting with the included alcohol wipe. Remove adhesive and hold mount in place with light pressure for 10 seconds. Remove the comma device and press firmly on the mount. Let the adhesive cure for 48 hours.

    Before placing the device on your windshield, check the state and local laws and ordinances where you drive. Some state laws prohibit or restrict the placement of objects on the windshield of a motor vehicle. IT IS THE USER'S RESPONSIBILITY TO MOUNT THE DEVICE IN COMPLIANCE WITH ALL APPLICABLE LAWS AND ORDINANCES. Always mount your device in a location that does not obstruct the driver's view of the road. comma does not assume any responsibility for any fines, penalties, or damages that may be incurred as a result of any state or local law or ordinance relating to the use of your comma device.

    Note: In California, a system with driver monitoring can be mounted on the top center of windshield.

    Will installing a comma device void my warranty?

    From the FTC website: "Simply using an aftermarket or recycled part does not void your warranty. The Magnuson-Moss Warranty Act makes it illegal for companies to void your warranty or deny coverage under the warranty simply because you used an aftermarket or recycled part."

    Will my insurance cover my car with a comma device installed?

    Contact your insurance provider directly; insurance coverage is between the user and their insurance provider. comma hardware users have been able to get coverage and discuss this on reddit here.

    Insurance companies are beginning to understand the safety benefits of ADAS and LKAS systems like openpilot and we have not heard of any providers rejecting coverage to comma hardware users.

    How long will my device have software support?

    Although there's no official support for any software, it is comma's policy to continue providing software updates to hardware for 1 year after it is the latest generation sold.

    Join the conversation

    Have a question or want to learn more? There are thousands of knowledgeable community members on the Discord.


    Developer Resources

    Check out the code behind the the comma three and openpilot. Review, fork, and contribute to the open source ecosystem.