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:
Replacement
1. Remove proportioning valve assy
Using sst, disconnect the 5 brake tubes from the proportioning
valve assy.
Sst 09023–00100
Remove the 2 bolts and proportioning valve assy from the
body.
2. Install proportioning valve assy
Install the proportioning valve assy w ...
Heater control & accessory assy
Replacement
1. Remove console panel upper
2. Remove instrument cluster finish panel
3. Remove heater control & accessory assy
Release the 2 fitting claws and pull out the heater control
& accessory assy.
Using a screwdriver, open the claw of the cable clamp and
dis ...
Circuit description
The fuel trim is related to the feedback compensation value, not to the basic
injection time. The fuel trim includes
the short–term fuel trim and the long–term fuel trim.
The short–term fuel trim is the short–term fuel compensation used to maintain
the air–fuel ratio at stoichiomet ...


