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:
Coolant
Replacement
1. Drain coolant
Caution:
to avoid the danger of being burned, do not remove the radiator
cap while the engine and radiator are still hot, as fluid
and steam can be blown out under pressure.
remove the radiator cap.
loosen the radiator and engine drain plugs, a ...
How to proceed with troubleshooting
1 Vehicle brought to workshop
2 Customer problem analysis
3 Check and clear dtc
4 Problem symptom confirmation
Symptom does not occur (go to
step 5)
5 Symptom simulation
6 Dtc check
7 Dtc chart
8 Problem symptoms table
9 Circuit inspection
10 Confirmation test
End
...
Check and replace ecu
Notice:
start an inspection of the connector from the backside
of the connector on the wire harness side with
the connector connected to the ecu.
When no measurement condition is specified, perform
the inspection with the engine stopped and also
the ignition switch on.
First check the ec ...


