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:
On–vehicle inspection
Notice:
”cold” and ”hot” in these sentences express the temperature of the coils
themselves. ”Cold” is from
–10 c (14 f) to 50 c (122 f) and ”hot” is from 50 c (122 f) to 100 c (212 f).
1. Inspect ignition coil (with igniter) and spark test
confirm dtc.
Notice:
...
Inspection procedure
1 Check d squib circuit(airbag sensor assy center – horn button
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 horn button assy.
release the airbag ...
Removal & installation and disassembly & reassembly
1. Remove bench type rear seat cushion assy
2. Remove rear floor service hole cover
Remove the rear service hole cover.
Disconnect the fuel pump and vapor pressure sensor
connector.
3. Work for preventing gasoline from spilling out
Start the engine.
after the engi ...


