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:
Purpose of the readiness tests
The on–board diagnostic (obd ii) system is designed to monitor the
performance of emission–related
components and report any detected abnormalities in the form of diagnostic
trouble codes
(dtcs). Since the various components need to be monitored during different
driving condition ...
Circuit description
Refer to dtc p0120
Dtc no.
Dtc detection condition
Trouble area
P0121
The following condition is met 4 times. After the vehicle speed
has exceeded 19 mph (30 km/h) once, the throttle position
sensor output value is out of normal range when the throttle
...
Circuit description
Refer to dtcs p0100
Dtc no.
Dtc detection condition
Trouble area
P0101
After engine is warmed up, conditions (a) to (d) continue for
more than 10 seconds (2 trip detection logic):
engine speed less than 900 rpm
throttle valve fully closed
&nbs ...


