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:
Engine coolant
The coolant level is satisfactory if it is between the “F” and “L” lines on the
reservoir when the engine is cold.
1 Reservoir cap
2 “F” line
3 “L” line
If the level is on or below the “L” line, add coolant up to the “F” line.
■Coolant selection
Only use “To ...
How to proceed with troubleshooting
1 Vehicle brought to workshop
2 Customer problem analysis
3 Problem symptom confirmation
4 Circuit inspection
5 Repair or replace
6 Confirmation test
7 End
Customer problem analysis check
...
Circuit description
The seat belt buckle switch (lh) circuit consists of the airbag sensor assy
center and front seat inner belt
assy (lh).
Dtc b0126/b0127/27 is recorded when a malfunction is detected in the seat belt
buckle switch (lh) circuit.
Wiring diagram
...