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 Check door lock
2 Check wire harness (tvip ecu door lock)
Disconnect the tvip ecu and door lock connectors.
check the continuity between the terminals of the tvip
ecu and door lock connectors, as shown in the illustration
and table.
Standard:
3 Check wire harness ...
Source voltage drop
The srs is equipped with a voltage–increase circuit (dc–dc converter) in the
airbag sensor assy center
in case the source voltage drops.
When the battery voltage drops, the voltage–increase circuit (dc–dc converter)
functions to increase the
voltage of the srs to normal voltage.
...
Overhaul
1. Remove speedometer drive (mtm) gear
Remove the speedometer drive (mtm) gear from the front
differential case.
2. Remove front differential ring gear
Place matchmarks on the front differential ring gear and
front differential case.
Remove the 8 bolts. Using a hamme ...


