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:
Pre–check
1. Diagnosis check
Starting diagnosis mode (service check mode)
turn off the audio system and turn the ig switch to
acc. While pressing the preset switches ”1” and ”6”
at the same time, press ”cd” 3 times.
Reference:
beep sound is given 3 times and the sys ...
Emission inspection and maintenance (I/M) programs
Some states have vehicle emission inspection programs which include OBD (On
Board Diagnostics) checks. The OBD system monitors the operation of the emission
control system.
If the malfunction indicator lamp comes on
The OBD system determines that a problem exists somewhere in the emission cont ...
How to proceed with troubleshooting
1 Vehicle brought to workshop
2 Customer problem analysis
3 Check and clear dtcs and freeze frame data
4 Problem symptom confirmation
Symptom does not occur: go to
step 5
Symptom occurs: go to step 6
5 Symptom simulation
6 Dtc check
There is no
output: go to step 7
There is outp ...


