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:
Malfunction in tachometer
Wiring diagram
Inspection procedure
Check output value of ecm.
Connect the hand–held tester to dlc3.
Turn the ignition switch to on and push the hand–held tester main switch
on.
Select the data list mode on the hand–held tester.
2 Inspect combinatio ...
Pressing power switch does not start system
Wiring diagram
Inspection procedure
1 Inspect radio receiver assy(+b, acc, gnd)
Check that the continuity between terminals at each
condition, as shown in the chart.
Standard:
Check that the voltage between terminals at each condition,
as shown in the chart.
Standard:
...
Emission inspection and maintenance (I/M) programs
Some states have vehicle emission inspection programs which include OBD (On
Board Diagnostics) checks. The OBD system monitors the operation of the emission
control system.
If the malfunction indicator lamp comes on
The OBD system determines that a problem exists somewhere in the emission cont ...


