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:
read freeze frame data using the hand–held tester or the obd ii scan tool.
Freeze frame data records the
engine conditions when a malfunction is detected. When troubleshooting, it is
useful for determining whether
the vehicle was running or stopped, the engine was warmed up or not, th ...
Steering column
Preparation
Sst
Recomended tools
Equipment
...
Road test
1. Problem symptom confirmation
Taking into consideration the results of the customer problem analysis,
try to reproduce the symptoms
of the trouble. If the problem is that the transaxle does not shift up,
shift down, or the shift point is too
high or too low conduct the following road ...


