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:
Engine immobilizer system
The vehicle's keys have
built-in transponder chips
that prevent the engine from
starting if a key has not
been previously registered
in the vehicle's on-board
computer.
Never leave the keys inside
the vehicle when you leave
the vehicle.
This system is designed to
help prevent vehicle theft
but doe ...
Circuit description
The speed sensor detects wheel speed and transmits the appropriate
signals to the ecu. These signals are used for control
of the abs control system. Each of the front and rear rotors has
48 serrations.
When the rotors rotate, the magnetic field generated by the permanent
magnet in the spe ...
Circuit description
The ecm compares the two waveforms of the heated oxygen sensors located
before and after the catalyst
to determine whether or not the catalyst performance has deteriorated.
Air–fuel ratio feedback compensation keeps the waveform of the heated oxygen
sensor in front of the catalyst
alterna ...