Toyota Lexusc Owner's Handbook Manual page 497

STARTING AND DRIVING
(k) Laser radar sensor
The laser radar sensor is used for vehicle-to-vehicle
distance control cruising.
If dirt is on the sensor glass, the dynamic laser cruise
control function is automatically cancelled and a warning
code appears on the display. (See "(l) Vehicle-to-vehicle
distance control mode failure warning" on page 479.)
However, if the glass sensor is covered with icicle or any
substance, dirt may not be detected.
Before using the vehicle-to-vehicle distance control
mode, make sure the laser radar sensor glass is clean.
This product is a class I laser product complied with
21 C.F.R part 1040.10. and 1040. 11.
478
CAUTION
To ensure that dynamic laser cruise control will function
properly while driving, observe the following:
D Always keep the laser radar sensor glass clean.
When cleaning, use a soft cloth and be careful not to
damage the sensor.
D Avoid strong impacts around the laser radar sensor.
An incorrect laser radar sensor alignment will result
in system malfunction. A special device is required
to adjust the laser radar sensor alignment. Be sure
to have the sensor adjusted by your Lexus dealer.
D Do not affix a sticker (including a transparent sticker)
or attach an accessory around the laser radar sensor.