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:
Warning lights and indicators
The warning lights and indicators on the instrument cluster and center panel
inform the driver of the status of the vehicle’s various systems.
For the purpose of explanation, the following illustration displays all warning
lights and indicators illuminated.
► Vehicles with a drive moni ...
Foamed material application areas
If an increase in temperature or other condition damages the foamed material
when repairing or replacing the panel,
fill in the insufficient areas with urethane foam. The following illustration
shows the areas for one side, but the
foamed material must be applied equally to both the left and r ...
Inspection procedure
1 Check low pitched horn assy
Connect the positive (+) lead from the battery to the terminal
and negative (–) lead to the horn body, and check that
the horn blows.
2 Check relay (marking: horn)
Remove the relay from the engine room j/b.
check the horn relay conti ...


