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. Remove hood sub–assy
2. Remove cylinder head cover no.2
3. Remove battery
4. Remove battery carrier
Remove the 4 bolts and battery carrier.
5. Remove air cleaner assembly with hose
6. Remove floor shift cable transmission control shift
Remove the nut from the control shaf ...
Inspection procedure
1 Inspect dlc3 terminal voltage
Turn the ignition switch to on.
measure voltage between terminals 13 (tc) and 4 (cg) of
dlc3.
Ok:
voltage: 10 – 16 v
2 Check harness and connector(between cruise control ecu assy
and dlc3)
Check for open and short circuit in harness ...
Overhaul
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 brake master cylinder sub–assy
disconnect the brake fluid level switch connector from
master cylinder reservoir subâ ...


