Installation#

Install in Sleep Mode#

Your Rivian must be asleep during harness installation. Multiple cases of Driver+ deactivation have occurred when connecting the comma harness with the Rivian awake. The comma device may also fail to receive power.

To put your Rivian to sleep:

  1. Turn off Gear Guard
  2. Open passenger door, lock the Rivian, leave the door ajar
  3. Turn off Bluetooth on your phone
  4. Walk away for 15–20 minutes (keep key fob out of range)
  5. Turn off your phone’s WiFi hotspot connection if applicable
  6. Return to the passenger side — all screens should remain off
  7. Do not place weight on the driver or passenger seat
  8. Connect the harness, then wake the vehicle
  9. Connect the comma device and proceed

Install stock openpilot first to verify your hardware setup is correct. Switch to sunnypilot later if you want longitudinal control.

Tools#

  • Torx T20 screwdriver, flathead screwdriver, plastic trim tool
  • Light source (floor lamp or headlamp)
  • Socket wrench with 13mm deep socket (fuse panel bolt)
  • L-shaped tool and long needle-nose pliers (connector handling)

Harness Installation#

The harness connects to the Autonomy Experience Module (AXM) behind the passenger side footwell panel.

The AXM has:

  • A removable white connector in front — remove this first for easier access
  • A slot where the comma harness connector slides in

Use a flathead screwdriver to gently push up on the release tab at the bottom left of the white connector while pushing it out.

Community tips:

  • Later model Rivians have a large cable harness to the left of the fuse panel leg. Removing the bolt and pulling the fuse panel connection out and to the left gives more room.
  • Fold the carpet back toward you — minor styrofoam breakage is fine and tucks back.
  • Running your left hand behind the fuse panel support makes plug guidance easier.
  • An L-shaped tool is invaluable for connector manipulation.

Video guides:

Windshield Placement#

The comma 3X requires an 8-degree mount. The comma four doesn’t strictly need it but performs better with it.

Attach the mount about 1 inch below the center of the rear-view mirror — not the whole assembly, since the Mobile Eye housing is off-center. The center of the windshield is aligned with the hump of the rear-view mirror mount.

Backward Rivian Cable Routing Forward