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 buzzer does not sound (key reminder
warning, light reminder warning)
Wiring diagram
Inspection procedere
1 Check buzzer
Check that all of the warning buzzers sound.
2 Inspect front door courtesy lamp switch assy
3 Inspect un–lock warning switch assy
4 Check harness and connector(between un–lock warning switch
and combination meter as ...
General information
There are many ecu controlled systems used in the corolla. In general, ecu
controlled system are considered
to be very intricate and require a high level of technical knowledge and expert
skill to troubleshoot.
The fact is, however, that if you proceed by inspecting the circuits one by one, ...
Inspection procedure
1 Check fuse(ecu–ig)
Remove the ecu–ig fuse from the instrument panel j/b.
check the continuity of the ecu–ig fuse.
Ok: continuity
2 Inspect terminal voltage(b)
Remove the cruise control ecu assy with connector still
connected.
turn the ignition switch ...


