Lexus 2003 LS Owner's Manual page 66

GAUGES, METERS AND SERVICE REMINDER INDICATORS
If either of the following conditions occurs, this indicates
a malfunction somewhere in the parts monitored by the
warning light system. Contact your Lexus dealer as soon
as possible to service the vehicle.
A The light does not come on when the ignition switch is
turned to the "ON" position, or remains on.
A The light comes on while you are driving.
A warning light turning on briefly during operation does not
indicate a problem.
CAUTION
If the "ABS" warning light remains on together with the
brake system warning light, immediately stop your
vehicle at a safe place and contact your Lexus dealer.
In this case, not only the anti–lock brake system will fail
but also the vehicle will become extremely unstable
during braking.
(i) Open Door Warning Light
This light remains on until all the doors are completely closed.
52
(j) Low Fuel Level Warning Light
This light comes on when the fuel level in the tank becomes
very low. Fill the tank as soon as possible.
On inclines or curves, due to the movement of fuel in the tank,
the low fuel level warning light may come on earlier than usual.
(k) Key Reminder Buzzer
This buzzer reminds you to remove the key when you open the
driver's door with the ignition key in the "ACC" or "LOCK"
position.