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:
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 ...
Check and replace ecu
Notice:
start an inspection of the connector from the backside
of the connector on the wire harness side with
the connector connected to the ecu.
When no measurement condition is specified, perform
the inspection with the engine stopped and also
the ignition switch on.
First check the ec ...
Replacement
1. Work for preventing gasoline from spilling out
2. Remove front wheels
3. Remove engine under cover rh
4. Remove engine under cover lh
5. Drain coolant
6. Remove cylinder head cover no.2
Remove the 2 nuts, 2 clips and cylinder head cover.
7. Disconnect radiator hose inlet
&nb ...


