Lexus ES300 Owner's Manual page 25

Flat key
As a transponder chip is built in its key case, you can start
the engine with this key.
The flat key works in every lock.
A transponder chip for engine immobiliser system has been
placed in the key case of the flat key. This chip is needed to
enable the system to function correctly, so be careful not to
lose this key. If you make your own duplicate key, you will not
be able to cancel the system or start the engine.
Insert your key plate in its key case as shown. We recommend
that you always carry this with you for emergency use. Do not
leave it in your vehicle.
KEYS AND DOORS
Starting the engine using a flat key
1. Remove the key plate from the key case.
2. Insert the key plate into the ignition switch. The indicator
light keeps flashing.
3. Bring the key case closer to the ignition switch within 10
seconds as indicated by the arrow head. The indicator light
goes out. This means the engine immobiliser system is
automatically canceled. (For details, see "Engine immobiliser
system" on page 14.) You can put the key case away then. You
cannot cancel the engine immobiliser system if 10 seconds
have past after you inserted the key plate. You need to remove
the key plate from the ignition switch and try it again from the
step 2.
4. Start the engine within 20 seconds after the security
indicator light goes out. You cannot start the engine if 20
seconds have past after the security indicator went off. You
need to remove the key plate from the ignition switch and try
it again from the step 2.
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