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
If the engine coolant temperature (ect) does not reach 75°c (167°f) despite
sufficient warm – up time has
elapsed.
Dtc no
Dtc detection condition
Trouble area
P0128
Condition (a), (b) and (c):
cold start
after engine is warmed up
& ...
Outside temperature display
The temperature display shows temperatures within the range of -40°F (-40°C)
to 122°F (50°C).
► Type A
► Type B
► Type C
► Type D
■The outside temperature is displayed when
►Vehicles without a smart key system
The engine switch is in the “ON ...
Trip information
■ Switching the display
Items displayed can be switched by pressing the “DISP” switch.
■ Odometer
Displays the total distance the vehicle has been driven.
Except vehicles with a manual transmission: Press and hold the “DISP” switch
to change the display to the Eco Driving ...


