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:
Indicators
The indicators inform the driver of the operating state of the vehicle’s various
systems.
*1: Vehicles without a smart key system:
These lights turn on when the engine switch is turned to the “ON” position to indicate
that a system check is being performed. They will turn off after the ...
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 ...
Evap monitor (vacuum pressure monitor) (continued)
Preconditions
The monitor will not run unless:
mil is off.
Fuel level is approximately 1/2 to 3/4.
Altitude is 7800 feet (2400 m) or less.*
Engine coolant temperature (ect) is between 40°f and 95°f (4.4 °C and 35
°C).
Intake air temperature (iat) is between 40°f and 95 ...


