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:
Manual air conditioning system
Air conditioning controls
The display and button positions will differ depending on the type of
the system.
Fan speed control switch
Temperature control switch
"MAX A/C" switch
"A/C" switch
Outside air mode switch
Recirculated air mode switch
Airflow mode control switch
Rear window defogge ...
Key information
Keys
The following keys are provided with the vehicle.
► Vehicles without a smart key system
(type A)
1 Keys
2 Key number plate
► Vehicles without a smart key system (type
B)
1 Keys
Operating the wireless remote control function
2 Key number plate
► Vehicles ...
Check mode procedure
Hint:
hand–held tester only:
compared to the normal mode, the check mode has more sensing
ability to detect malfunctions. Furthermore, the same diagnostic
items which are detected in the normal mode can also be
detected in the check mode.
1. Check mode procedure(using the hand–held tester) ...


