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:
Checking the messages
1 Display the “Message Inbox” screen.
2 Select the desired message from the list.
3 Check that the message is displayed.
1 E-mails: Select “Mark Unread” or “Mark Read” to mark mail unread or read on
the message inbox screen.
This function is available when “Update Message Read S ...
Communication system
Horn system
Location
Problem symptoms table
Inspection
1. Inspect low pitched horn assy
Connect the positive (+) lead from the battery to the terminal
and the negative (–) lead to the horn body, and check
that the horn blows.
If the result is not as specified, replace the ...
Wireless remote control/electronic key battery
Replace the battery with a new one if it is depleted.
You will need the following items:
● Flathead screwdriver
● Small flathead screwdriver
● Lithium battery CR2016 (vehicles without a smart key system), or CR2032 (vehicles
with a smart key system)
Replacing the battery
...


