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:
Overhaul
Notice: when installing, coat the parts indicated by the arrow with
power steering fluid or molybdenum disulfide lithium base grease.
1. Precaution
2. Disconnect battery negative terminal
3. Inspect center front wheel
4. Remove horn button assy
5. Remove steering wheel assy
sst 09950–50013 ...
Overhaul
Hint: components:
1. Remove front wheel
2. Disconnect front stabilizer link assy lh
Remove the nut and disconnect the front stabilizer link
assy lh from the shock absorber assy front lh.
Hint:
if the ball joint turns together with the nut, use a hexagon (6 mm)
wrench to hold the st ...
Definition of terms
Term
Definition
Monitor description
Description of what the ecm monitors and how it detects malfunctions
(monitoring purpose and its details).
Related dtcs
Diagnostic code
Typical enabling condition
Preconditions that allow the ecm to detect ...


