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:
How to proceed with troubleshooting
Hint:
troubleshooting of the wireless door lock control system is based on
the premise that the power door
lock system is operating normally. Therefore, before troubleshooting the
wireless door lock control system,
first make certain that the the power door lock system is operating
...
Replacement
1. Work for preventing gasoline from spilling out
2. Remove cylinder head cover no.2
Remove the 2 nuts, 2 clips and cylinder head cover.
3. Disconnect ventilation hose
Disconnect the ventilation hose from the cylinder head
cover.
4. Disconnect engine wire
Disconnect ...
Inspection procedure
1 Inspect parking brake switch circuit
Check for open and short circuit in parking brake switch circuit
2 Inspect brake fluid level warning switch circuit
Check the brake fluid level in reservoir.
check for open and shot circuit in brake fluid level warning
switch circuit
...


