SFI SYSTEM MIL Circuit

DESCRIPTION

The MIL (Malfunction Indicator Lamp) is used to indicate vehicle malfunctions detected by the ECM. When the ignition switch is turned to ON, power is supplied to the MIL circuit and the ECM provides the circuit ground which illuminates the MIL.

The MIL operation can be checked visually: When the ignition switch is first turned to ON, the MIL should be illuminated, and should then turn off when the engine is started. If the MIL remains illuminated or is not illuminated, conduct the following troubleshooting procedure using the intelligent tester.

INSPECTION PROCEDURE

PROCEDURE

1. Click here

   CHECK THAT MIL IS ILLUMINATED

   
   

   1. Check that the MIL is illuminated.

      Table 1. Result

      Result	Proceed to
      MIL remains on	A
      MIL does not illuminate	B

   
   
   • AClick here
   • BClick here
2. Click here

   CHECK WHETHER MIL TURNS OFF

   
   

   1. Connect the intelligent tester to the DLC3.

   2. Turn the ignition switch to ON and turn the tester on.

   3. Check for DTCs (Click here). If DTCs are output, write them down.

   4. Clear the DTCs (Click here).

   5. Check that the MIL turns off.

      OK
      MIL turns off.

   
   
   • OKClick here
   • NGClick here
3. Click here

   CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT IN WIRE HARNESS)

   
   

   1. Disconnect the ECM connector.

   2. Turn the ignition switch to ON.

   3. Check that the MIL is not illuminated.

      OK
      MIL is not illuminated.

   4. Reconnect the ECM connector.

   
   
   • OKClick here
   • NGClick here
4. Click here

   CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)

   
   

   1. Disconnect the ECM connector.

   2. Disconnect the combination meter assembly connector.

   3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition G7-7 (CHK) - G55-13 (W) Always Below 1 Ω

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition G7-7 (CHK) or G55-13 (W) - Body ground Always 10 kΩ or higher

   4. Reconnect the ECM connector.

   5. Reconnect the combination meter connector.

   
   
   • OKClick here
   • NGClick here
5. Click here

   CHECK THAT MIL IS ILLUMINATED

   
   

   1. Check if the MIL is illuminated when the ignition switch is turned to ON.

      OK
      MIL is illuminated.

   
   
   • OKClick here
   • NGClick here
6. Click here

   CHECK THAT ENGINE STARTS

   
   

   1. Turn the ignition switch to ON.

   2. Start the engine.

      Table 2. Result

      Result	Proceed to
      Engine starts	A
      Engine does not start*	B

      Tip:

      *: The intelligent tester cannot communicate with the ECM.

   
   
   • AClick here
   • BClick here
7. Click here

   INSPECT COMBINATION METER ASSEMBLY (MIL CIRCUIT)

   
   

   1. Refer to the combination meter troubleshooting procedure (Click here).

   
   
   • OKClick here
   • NGClick here
8. Click here

   REPLACE COMBINATION METER ASSEMBLYClick here

9. Click here

   GO TO VC OUTPUT CIRCUITClick here

10. Click here

    REPLACE COMBINATION METER ASSEMBLYClick here

11. Click here

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCSClick here

12. Click here

    REPLACE ECMClick here

13. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

14. Click here

    SYSTEM OK

15. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR (COMBINATION METER ASSEMBLY - ECM)