Toyota Corolla (E120) 2002–2008 Repair Manual / Introduction / How to troubleshoot ecu controlled
systems / Problem symptoms table
Toyota Corolla (E120): Problem symptoms table
The suspected circuits or parts for each problem symptom are shown in the table below. Use this table to troubleshoot the problem when a normal code is displayed in the diagnostic trouble code chart but the problem is still occurring. Numbers in the table indicate the order in which the circuits or parts should be checked.
Hint: when the problem is not detected by the diagnostic system even though the problem symptom is present, it may be that the problem is occurring outside the detection range of the diagnostic system.

Other materials:
No sound is heard from speaker in all modes
Wiring diagram
Inspection procedure
1 Check lcd (liquid crystal display) for lighting
Lcd illumination check
turn the ignition switch acc.
Turn the radio receiver assembly on.
Standard: lcd illumination of the radio receiver assembly light.
2 Control fader and ...
Noise occurs
Inspection procedure
1 Check of speaker installation
Check speaker installation condition.
Check that each speaker is securely installed.
Standard: malfunction disappear.
Hint:
the radio is equipped with noise prevention system that does not work against
the regular use of t ...
Inspection procedure
1 Check wire harness(airbag sensor assy center – front seat inner
belt assy lh)
Disconnect the negative (–) terminal cable from the battery,
and wait at least for 90 seconds.
disconnect the connectors between the airbag sensor
assy center and the front seat inner belt assy ( ...


