Adaptive Cruise Control#

Adaptive cruise control (ACC) allows openpilot to accelerate and slow down based on traffic and your set speed. On preAP Tesla Model S, the level of ACC depends on your hardware setup.

Without an iBooster, the car only uses regenerative braking. This is not sufficient for sudden slowdowns. You must be ready to manually brake at any moment.

Hardware Levels#

Setup Speed Range Braking Lead Car Detection
No pedal (stock cruise) Above 18 MPH Stock Tesla cruise only Vision (1 car, 1–2s delay)
Comma Pedal 1–18+ MPH (regen above 5 MPH) Regenerative only Vision (1 car, 1–2s delay)
Pedal + Tesla Bosch Radar 1–18+ MPH (regen above 5 MPH) Regenerative only Radar (up to 32 objects, real-time)
Pedal + Radar + iBooster Full stop-and-go Electronic brakes (AEB) Radar (up to 32 objects, real-time)

Two Cruise Modes#

openpilot has two cruise control modes depending on whether Tesla’s built-in cruise or the comma pedal is active:

  • ACC (Adaptive Cruise Control) — uses Tesla’s stock cruise control via stalk commands. Only works above 18 MPH.
  • PCC (Pedal Cruise Control) — uses the comma pedal for smoother control down to 1 MPH. Requires Tesla cruise to be off.

To switch between them, press the cruise stalk IN to toggle Tesla cruise on/off. See Tesla Unity Configuration for the “Use pedal over CC” option.

Using Cruise Control#

Engaging ACC (stock cruise)#

  1. Press the cruise stalk IN so the orange cruise LED is lit.
  2. Accelerate above 18 MPH.
  3. Double-pull the cruise stalk backwards to engage openpilot.
  4. Adjust speed with stalk UP/DOWN.
  5. Cruise disengages on brake or below 18 MPH.

Engaging PCC (pedal)#

  1. Make sure the cruise stalk LED is off (or enable “Use pedal over CC” in settings).
  2. Accelerate above 1 MPH.
  3. Double-pull the cruise stalk backwards to engage openpilot.
  4. Adjust speed with stalk UP/DOWN.
  5. Cruise disengages on brake.

Controls Reference#

Control Action
Cruise stalk IN Toggle Tesla cruise on/off (ACC vs PCC)
Cruise stalk double-pull Engage openpilot
Cruise stalk UP Increase cruise speed
Cruise stalk DOWN Decrease cruise speed
Cruise stalk push forward Disengage openpilot
Brake pedal Pause cruise control
Accelerator Override speed (in ACC AUTO mode, resume by accelerating above 18 MPH)