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:
Circuit description
The crankshaft position sensor (ne signal) consists of a magnet, iron core
and pickup coil.
The ne signal plate (crankshaft position sensor plate) has 34 teeth and is
installed on the crankshaft. The
ne signal sensor generates 34 signals for each engine revolution. This sensor
monitors a p ...
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.
Vehicles without a smart key system: The indicator li ...
Basic repair hint
(A) hints on operations
1
Looks
Always wear a clean uniform.
Hat and safety shoes must be worn.
2
Vehicle protection
Set a grill cover, fender cover, seat cover and floor mat before
starting the operation.
3
Safe ...


