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:
Introductions
4. Anti-rust treatment after installation
(A) body sealer application
Purpose:
for water-proofing and anti-rust measures, always
apply the body sealer to the body panel seams and
hems of the doors, hood, etc.
Notice:
apply body sealer neatly to parts that require a
high quality appeara ...
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
...
Inspection procedure
1 Check un–lock warning switch assy
Disconnect the key unlock warning switch connector.
check the continuity between the terminals of the key unlock
warning switch connector, as shown in the illustration
and table.
Standard:
2 Check wire harness (tvip ecu unlock warni ...


