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:
Identification information
Vehicle identification and serial numbers
1. Vehicle identification number
The vehicle identification number is stamped on the vehicle
identification number plate and certification label, as
shown in the illustration.
Vehicle identification number plate
certification label
2. Engine ...
Inspection
1. Thermostat
Hint:
the thermostat is numbered with the valve opening temperature.
Immerse the thermostat in water and gradually heat the
water.
check the valve opening temperature.
Valve opening temperature:
80 to 84 c (176 to 183 f)
Hint:
if the valve opening temperatur ...
Battery
Check the battery as follows.
■ Battery exterior
Make sure that the battery terminals
are not corroded and that
there are no loose connections,
cracks, or loose clamps.
Terminals
Hold-down clamp
■Before recharging
When recharging, the battery produces
hydrogen gas which is flammable
and exp ...


