Toyota Corolla (E120) 2002–2008 Repair Manual / Introduction / How to troubleshoot ecu controlled
systems / Diagnostic trouble code chart
Toyota Corolla (E120): Diagnostic trouble code chart
The inspection procedures are shown in the table below. This table allows efficient and accurate troubleshooting using the diagnostic trouble codes displayed in the diagnostic trouble code chart. Proceed with troubleshooting in accordance with the inspection procedures listed in the diagnostic chart corresponding to the diagnostic trouble codes displayed. The diagnostic trouble code chart for the supplemental restraint system is shown below as an example.

Other materials:
What to do if... (Troubleshooting)
If you have a problem, check the following before contacting your Toyota dealer.
The doors cannot be locked, unlocked, opened or closed
You lose your keys
● If you lose your keys or mechanical keys, new genuine keys or mechanical keys
can be made by your Toyota dealer.
● If you lo ...
Sound quality is bad in all modes (volume is too low)
Wiring diagram
Inspection procedure
1 Adjust sound quality
Adjust the sound quality.
Operate the radio receiver assy to adjust the sound quality.
Standard: malfunction disappear.
2 Compare it with another car of same model
Compare it with another vehicle of the same mo ...
Inspection procedure
1 Check operation(stop lamp swtich assy)
Check that the stop light comes on when the brake pedal is depressed,
and turns off when the brake
pedal is released.
2 Input signal check
See input signal check on page 05–745.
check the indicator light when the brake pedal ...


