Lexus GS430 User Manual page 377

Steering lock
The steering wheel is locked when the engine switch is
turned to "OFF" from "ACC" or "IG−ON" mode and any
door is opened.
When the steering lock is activated, you may hear a sound
coming from the steering column, it is not a malfunction. If you
select the "OFF" mode while any door is open, the steering
wheel is not locked until it is closed.
If you select the mode other than "OFF" or start the engine, the
steering lock is disabled.
If there is trouble somewhere in the steering lock system, either
of the following warning messages will appear on the
multi−information display.
D S/T IS NOT UNLOCKED
D CHECK S/T LOCK
STARTING AND DRIVING
G31045
When pushing the engine switch while the brake pedal is
depressed, the steering lock is not unlocked if load is
applied to the steering wheel, and the above message
appears.
The engine will not start. At this time, the master warning light
comes on and the engine switch indicator light blinks green.
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