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
Hint:
if dtcs p0115, p0116, p0117, p0118 and p0125 are output
simultaneously, the engine coolant temperature
sensor circuit may be open or short. Perform the troubleshooting of dtc
p0115, p0117 or
p0118 first.
Read freeze frame data using the hand-held tester or the obd ii scan
to ...
Noise occurs
Inspection procedure
1 Check of speaker installation
Check speaker installation condition.
Check that each speaker is securely installed.
Standard: malfunction disappear.
Hint:
the radio is equipped with noise prevention system that does not work against
the regular use of t ...
Repair
1. Steering off center repair procedure
Inspect steering wheel off center.
Apply masking tape on the top center of the steering
wheel and steering column upper cover.
Driving the vehicle on a straight line for 100 meters
at a constant speed of 35 mph (56 km/h), and ho ...


