Toyota Corolla (E120) 2002–2008 Repair Manual / Introduction / How to troubleshoot ecu controlled
systems / How to proceed with troubleshooting
Toyota Corolla (E120): How to proceed with troubleshooting
Hint
: carry out troubleshooting in accordance with the procedures on the following page. Here, only the basic procedures are shown. Details are provided in the diagnostics section, showing the most effective methods for each circuit. Confirm the troubleshooting procedures first for the relevant circuit before beginning troubleshooting of that circuit.
1 Vehicle brought to workshop

2 Customer problem analysis
- ask the customer about the conditions and environment when the problem occurred.

- Check the battery positive voltage.
Voltage: 11 – 14 v (engine stopped)
- visually check the wire harness, connectors and fuses for open and short, etc.
- warm up the engine to the normal operating temperature.
- confirm the problem symptoms and conditions, and check for dtcs according to the related chart.
Ok go to step 5

4 Dtc chart
- Check the results obtained in step 3, then confirm the inspection procedures for the system or the part which should be checked using the dtc chart.
Go to step 6
5 Problem symptoms chart
- Check the results obtained in step 3, then confirm the inspection procedures for the system or the part which should be checked using the problem symptoms table.

6 Circuit inspection or parts inspection
- Confirm the circuit for the system or the part which should be checked using the problem symptoms table or the results obtained in step 4.

7 Repair
- Repair the affected system or part in accordance with the instructions in step 6.

8 Confirmation test
- After completing repairs, confirm that the problem has been solved (if the problem does not recur, perform a confirmation test under the same conditions and in the same environment as when it occurred for the first time).

End
Other materials:
Inspection
1. Charcoal canister assy
Visually check the charcoal canister for cracks or damage.
Inspect the charcoal canister operation.
Plug the vent port with the cap.
While holding the purge port closed, blow air (1.76
Kpa, 18 gf/cm2, 0.26 Psi) into the evap port and
...
Inspection procedure
1 Check airbag sensor assy center connector
Disconnect negative (–) terminal cable from the battery, and wait at
least for 90 seconds.
check the connection of the airbag sensor assy center connectors.
2 Check air bag sensor assy center
Sst 09843–18040
Connect the n ...
Circuit description
When a misfire occurs in the engine, hydrocarbons (hc) enter the exhaust in
high concentrations. If this hc
concentration is high enough, there could be an increase in exhaust emissions
levels. High concentrations
of hc passing through the catalyst also cause to temperature of the catalyst to ...


