See also:

Disabling pre-collision braking
1.Pre-collision braking disabled 2.Pre-collision braking enabled The “PCS” warning light turns on when pre-collision braking is dis- abled. ...

Have the vehicle inspected by your Lexus dealer immediately.
Failing to investigate the cause of the following warnings may lead to the system operating abnormally and possibly cause an accident. Have the vehicle inspected by your Lexus dealer immediately. ...

Electronic key battery
Replace the battery with a new one if it is depleted.  - You will need the following items: • Flathead screwdriver • Small Phillips-head screwdriver • Lithium battery (CR1632)  - ...