The adaptive cruise control (ACC) warning on your 2021 Lincoln Navigator indicates the system that maintains distance from vehicles ahead has detected a fault. This convenience and safety feature uses radar to automatically adjust your speed.
How Adaptive Cruise Works
Unlike conventional cruise control that maintains a set speed, ACC uses a radar sensor to detect vehicles ahead and automatically slows or accelerates to maintain a set following distance. When the road clears, it resumes your set speed. The warning indicates this automatic following function isn't available.
Radar Sensor Location
The Navigator's ACC radar is typically located in the front grille or bumper area. This location makes it vulnerable to damage from debris and obstruction from dirt, snow, ice, or bugs. Sensor obstruction is a common cause of ACC warnings.
Weather and Environmental Factors
Heavy rain, snow, fog, or blowing dust can prevent radar from functioning properly. The system may display warnings or become unavailable during adverse conditions. Operation should restore when conditions improve.
Calibration Issues
ACC radar requires precise alignment. Front-end collision repairs, bumper replacement, or even significant wheel alignment changes can necessitate recalibration. If your warning appeared after any front-end service, calibration may be needed.
System Integration
ACC works with other Lincoln Co-Pilot360 features. Stop and Go capability, Lane Centering, and Pre-Collision Assist share sensors and data. Faults affecting ACC may also disable related features.
Conventional Cruise Availability
When ACC isn't available, conventional cruise control (without automatic following) may still work. You can maintain set speeds; you just won't have automatic distance maintenance. Check if basic cruise functions while ACC is faulted.