Enable or disable Speed Sign Recognition on Ford F-150 – (Speed Limit Assist)

Speed Sign Recognition system on Ford F-150 detects speed limit signs on the road to inform you of the current speed limit. Detected speed signs appear in the instrument cluster display.

Speed Limit Assist on Ford F-150, 14th generation

How does speed sign recognition work?

Speed sign recognition on Ford F-150 uses a sensor behind the interior mirror to detect speed signs. If your vehicle has speed sign recognition with navigation, stored speed sign data may influence the indicated speed limit value.

Switch speed sign recognition warning on and off

You can enable or disable speed sign recognition warning via SYNC 4 infotainment system on Ford F-150. You cannot completely disable the system, the information display will still show detected speed limit – only overspeed warning alert will be disabled.

  1. Go to Features tab on the center touchscreen.
  2. Select Driver Assistance.
  3. Select Speed Limit Assist.
  4. Switch Speed Warning on or off.
Speed Limit Assist settings on SYNC 4, Ford F-150 14th generation

Adjust speed tolerance

You can set the tolerance for speed warning for speed sign recognition via the SYNC 4 infotainment system on F-150.

  1. Go to Features on the center touchscreen.
  2. Select Driver Assistance.
  3. Select Speed Limit Assist.
  4. Select Tolerance.
  5. Use the + and – buttons to select the required level.
Speed tolerance setting for speed sign recognition on SYNC 4, 14th gen F-150


When the system detects a speed limit sign, it appears in the infotainment system display.

Detected speed limit indicator (2021 F-150)

Which F-150 vehicles have speed sign recognition?

Speed sign recognition is part of Intelligent Adaptive Cruise under Ford Co-Pilot360 Assist 2.0 package which is standard on King Ranch, Platinum and Limited variants. Its an optional feature on XLT and Lariat. This feature is not available on base XL trim.

System Limitations

Speed sign recognition may not operate correctly due to:

  • Outdated map data.
  • Incorrect recognition of speed limits by the sensor of signs on parallel roads or exit ramps.
  • Missed recognition of faded, dirty, or distorted signs.


  • In cold and severe weather conditions the system may not function. Rain, snow and spray can all limit sensor performance.
  • The system may not operate properly if the sensor is blocked. Keep the windshield free from obstruction.
  • Do not carry out windshield repairs in the immediate area surrounding the sensor.
  • If your vehicle has a suspension kit not approved by us, the system may not correctly function.
  • The system may not detect all speed signs and may incorrectly read signs.
  • Always fit original parts from Ford when replacing headlamp bulbs. Other bulbs may reduce system performance.


Alert: Traffic Sign Reduced Performance See Manual

This message appears if the traffic sign data provided by the navigation system is unavailable due to weak or no signal. Wait for a short period of time for the signal to improve. If the message continues to appear, have the system checked as soon as possible.

Why does the speed limit change without any sign on the road?

The speed limit changes due to the speed limit data stored in the map data.

Why does speed sign recognition show a wrong speed limit?

The system shows a wrong speed limit due to incorrect and outdated map data or due to incorrect recognition of the speed limits by the camera.

Contact the author: joshwoods@wheelsjoint.com

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