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:
Diagnostics
Preparation
Sst
09816–30010
Oil pressure switch socket
Sfi system
09843–18040
Diagnosis check wire no.2
Sfi system
supplemental restraint
system
Recomended tools
09082–00040
Toyota electrical tester
Sfi system
supplemen ...
Manual shifting test
1. Perform manual shifting test
Hint:
by this test, it can be determined whether the trouble is within
the electrical circuit or is a mechanical problem in the transaxle.
Disconnect the transmission wire connector.
inspect the manual driving operation.
Check that the shift and g ...
How to proceed with troubleshooting
The hand–held tester can be used at step 3, 4, 5, 7, 10.
1 Vehicle brought to workshop
2 Customer problem analysis
3 Connect hand–held tester to dlc3
Hint:
if the display indicates a communication fault in the tool, inspect dlc3.
4 Check dtc and freeze frame data
Hint:
record or pr ...


