Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Mil circuit / Circuit description
Toyota Corolla (E120): Circuit description
The ignition switch provides circuit power and the ecm provides the circuit ground that illuminates the mil.
Mil operation is checked visually: it should be illuminated when the ignition is first turned on. If the mil is off all of the time or on all of the time, use the procedure below to troubleshoot it. The mil is used to indicate the ecm’s detection of a vehicle malfunction.
Follow this procedure using the hand–held tester or an obd ii scan tool to determine the cause of the problem and to check the mil.
Wiring diagram

Other materials:
Inspection procedure
1 Check p squib circuit(airbag sensor assy center – instrument
panel passenger airbag assy)
Disconnect the negative (–) terminal cable from the battery,
and wait at least for 90 seconds.
disconnect the connector between the airbag sensor
assy center and the instrument panel ...
Drive shaft / propeller shaft
Preparation
Sst
Recomended tools
Equipment
Lubricant
...
How to proceed with troubleshooting
The hand–held tester can be used at step 3, 4, 5, 7, 10.
1 Vehicle brought to workshop
2 Customer problem analysis
3 Connect hand–held tester to dlc3
Hint:
if the display indicates a communication fault in the tool, inspect dlc3.
4 Check dtc and freeze frame data
Hint:
record or pr ...


