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:
Replacement
1. Drain brake fluid
Notice:
wash the brake fluid off immediately if it comes into contact with any painted
surface.
2. Remove air cleaner cap sub–assy
3. Remove air cleaner case sub–assy
remove the air cleaner element, then remove the 3 bolts and air
cleaner case sub–assy.
...
Engine immobilizer system
The vehicle's keys have
built-in transponder chips
that prevent the engine from
starting if a key has not
been previously registered
in the vehicle's on-board
computer.
Never leave the keys inside
the vehicle when you leave
the vehicle.
This system is designed to
help prevent vehicle theft
but doe ...
Overhaul
1. Remove w/head taper screw plug no.2
Using a socket hexagon wench 10, remove the taper
screw plug and gasket.
2. Remove valve lifter
Remove the valve lifters from the cylinder head.
3. Remove valve
Place the cylinder head on wooden blocks.
using sst, compres ...


