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:
Inspection procedure
1 Prepare for inspection
Disconnect the negative (–) terminal cable from the battery, and wait at
least for 90 seconds.
remove the horn button assy .
disconnect the connector of the instrument panel passenger airbag assy
.
disconnect the connector of the front sea ...
Circuit description
The actuator motor is operated by signals from the cruise control ecu assy.
Acceleration and deceleration
signals are transmitted by changes in the duty ratio (see below).
Duty ratio:
the duty ratio is the ratio of the period of continuity in one cycle. For
example, if a is the period of co ...
Maintenance requirements
To ensure safe and economical driving, day-to-day care and regular maintenance
are essential. It is the owner’s responsibility to perform regular checks. Toyota
recommends the following maintenance:
General maintenance
General maintenance should be performed on a daily basis. This can be don ...


