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 harness and connector(transmission control switch –
body ground)
Disconnect the transmission control switch connector of
shift lever assy.
measure the resistance according to the value(s) in the
table below.
Standard:
2 Inspect transmission control switch
M ...
Replacement
Hint: components:
1. Place front wheels facing straight ahead
2. Remove front wheels
3. Remove engine under cover lh
4. Remove engine under cover rh
5. Remove exhaust pipe
6. Drain transaxle oil
7. Remove hood sub–assy
8. Remove cylinder head cover no.2
9. Remove air cleaner assy
10. R ...
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 ...


