ACC not available

Several conditions exist which can cause ACC to deactivate or prevent ACC from activating when requested. These conditions include:
• The sensor is blocked, refer to Blocked sensor in this section.
• Brake temperature is high, refer to Hilly condition usage in this
section.
• A failure has occurred in the ACC system or related system.
See also:
Washing the exterior
Wash your vehicle regularly with cool or lukewarm water and a neutral
pH shampoo, such as Motorcraft Detail Wash (ZC-3-A), which is
available from your authorized dealer.
• Never use strong house ...
Determining if the system is operational
The supplemental restraint system uses a warning indicator light in the
instrument cluster or a backup tone to indicate the condition of the
system. Refer to the Warning lights and chimes section ...
All-wheel drive (if equipped)
Your vehicle may be equipped with a full-time all-wheel drive (AWD)
system. The AWD system is an active system, meaning it not only
responds to wheel slip between the front and rear axles but also ...
