Toyota Corolla (E120) 2002–2008 Repair Manual / Introduction / How to troubleshoot ecu controlled
systems / Customer problem analysis
Toyota Corolla (E120): Customer problem analysis
Hint
:
- in troubleshooting, the problem symptoms must be confirmed accurately, meaning that all preconceptions must be set aside in order to make an accurate judgement. To ascertain what the problem symptoms are, it is extremely important to ask the customer about the problem and conditions when it occurred.
- The following 5 items are important points in the problem analysis. Past problems which are thought to be unrelated and the repair history, etc. May also help in some cases. Therefore, as much information as possible should be gathered and its relationship with the problem symptoms should be correctly ascertained for use as reference in troubleshooting. A customer problem analysis table is provided for your use in the diagnostics section for each system.

(Sample) supplemental restraint system check sheet.

Other materials:
How to proceed with troubleshooting
1 Vehicle brought to workshop
2 Customer problem analysis
3 Check and clear dtc
4 Problem symptom confirmation
Symptom does not occur (go to
step 5)
5 Symptom simulation
6 Dtc check
7 Dtc chart
8 Problem symptoms table
9 Circuit inspection
10 Confirmation test
End
...
Turning on light switch does not light up night time
illumination of radio receiver
Wiring diagram
Inspection procedure
1 Inspect radio receiver assy(ill+, ill–)
Check that the voltage between terminals at each condition,
as shown in the chart.
Standard:
Repair or replace harness or connector ...
On–vehicle inspection
1. Inspect drive belt
Visually check the belt for excessive wear, frayed cords,
etc.
If any defect is found, replace the drive belt.
Hint:
cracks on the rib side of a belt are considered acceptable. If the
missing chunks from the ribs are found on the belt, it should be
replaced.
2 ...


