CTA false alerts
Due to the nature of radar technology, there may be certain instances when the BLIS will alert with no object present when backing up. This is known as a false alert. Some level of false alerts are normal.
Circumstances that may cause a false alert when backing up are backing out of a garage, backing into a parking space, and objects very close to the sensor. False alerts are temporary and self correct.
See also:
Brakes
Occasional brake noise is normal. If a metal-to-metal, continuous grinding
or continuous squeal sound is present, the brake linings may be worn-out
and should be inspected by an authorized deale ...
Four-wheel anti-lock brake system (ABS)
Your vehicle is equipped with an anti-lock braking system (ABS). This
system helps you maintain steering control during emergency stops by
keeping the brakes from locking. Noise from the ABS pump ...