Lexus GS300 1998 Owner's Manual page 28

11L024–3
The engine immobiliser system is a theft prevention
system. When you insert the key in the ignition switch, the
transponder chip in the key's head transmits an electronic
code to the vehicle. The engine will start, only when the
electronic code in the chip corresponds to the registered
ID code for the vehicle.
The system is automatically set when the key is removed from
the ignition switch. At this time, the security indicator light
at the bottom of the instrument cluster flashes. When you
insert the key in the ignition switch, the security indicator
light goes out and the system is canceled automatically, which
enables the engine to start.
For your Lexus dealer to make you a new key with built–in
transponder chip, your dealer will need your key number and
master key. However, there is a limit to the number of
additional keys your Lexus dealer can make for you.
If you make your own duplicate key, you will not be able
to cancel the system or start the engine.
KEYS AND DOORS
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