Toyota Corolla (E120): Circuit description
The key unlock warning switch comes on when the ignition key is inserted in the key cylinder and goes off when the ignition key is removed.
Wiring diagram

Other materials:
On–vehicle inspection
1. Check battery electrolyte level
Check the electrolyte quantity of each cell (maintenance–free battery).
If under the lower level, replace the battery (or add distilled
water if possible) and check the charging
system.
check the electrolyte quantity of each cell ...
Engine immobilizer system
The vehicle's keys have
built-in transponder chips
that prevent the engine from
starting if a key has not
been previously registered
in the vehicle's on-board
computer.
Never leave the keys inside
the vehicle when you leave
the vehicle.
This system is designed to
help prevent vehicle theft
but doe ...
Replacement
Hint: components:
1. Precaution
2. Disconnect battery negative terminal
3. Remove seat track upper rail cover rh
4. Remove seat track upper rail cover lh
5. Remove front seat assy lh
6. Remove seat position air bag sensor
Disconnect the connector of the seat position airbag sensor. ...


