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 connectors between the airbag sensor
assy center and the instrument panel ...
Continuously variable transmission
(vehicles without paddle
shift switches)
Select the shift position
depending on your purpose
and situation.
Shift position purpose
and functions
P - Parking the vehicle/
starting the engine
R - Reversing
N - Neutral
(Condition in which the
power is not transmitted)
D - Normal driving*
B - Applying moderate
engine braking driving
down hills ...
How to proceed with troubleshooting
1 Vehicle brought in
2 Customer problem analysis check and symptom check
3 Problem symptoms table
Without applicable symptoms, proceed to ”a”
with applicable symptoms, proceed to ”b”
4 Perform troubleshooting in the following method, depending on
malfunction symptom ...