Symptoms
- Forward collision warning icon lit with a 'system unavailable' message
- No automatic braking or alerts for close following distance
- Common after a light front-end bump or a dirty sensor area
Likely causes
- CommonRadar sensor or camera blocked by dirt, ice, or debrisThese sensors are usually in the front grille or near the windshield and need a clear view.
- CommonFront bumper or grille damage misaligning the sensorEven minor fender-benders can knock the sensor out of alignment.
- PossibleHeavy rain, fog, or snow interfering with sensor readingsTemporary weather-related reduction in sensor reliability.
- Less commonSensor or module failureLess common, more likely on older vehicles or after significant impact.
What to do
- Clean the area around the front sensor, usually in the grille or bumper, of dirt, ice, or debris.
- Check for any visible damage to the front bumper or grille near the sensor location.
- Note if the warning appears mainly in bad weather, which may resolve once conditions improve.
- If there was a recent minor collision or bumper work, suspect sensor misalignment.
- Have a shop check sensor alignment and recalibrate it if needed, especially after any front-end work.
- Have the sensor or module tested and replaced if it doesn't respond even when clean and undamaged.
Tools and parts
- Cloth for cleaning sensor area
When to call a pro
See a mechanic or dealer for sensor alignment or recalibration after any front-end collision, even a minor one, since these systems rely on precise aiming.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.