SFI SYSTEM MIL Circuit

DESCRIPTION

The MIL (Malfunction Indicator Lamp) is used to indicate vehicle malfunction detected by the ECM. When the power switch is turned on (IG), 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 power switch is first turned on (IG), the MIL should illuminate and should then turn off. If the MIL remains illuminated or is not illuminated, conduct the following troubleshooting procedure using the intelligent tester.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. CHECK THAT MIL IS ILLUMINATED

   
   

   1. Turn the power switch on (IG).

   2. Check the illumination of the MIL.

      Result
      Condition Proceed to MIL remains illuminated (Even after power switch is turned on (IG) and several seconds have passed, MIL still remains illuminated) A MIL remains off (Does not illuminate at all) B MIL illuminates for several seconds, but turns off after engine is started C

   
   

   B

   CHECK THAT ENGINE STARTS Click here

   C

   SYSTEM OK

   A

2. CHECK WHETHER MIL TURNS OFF

   
   

   1. Connect the intelligent tester to the DLC3.

   2. Turn the power switch on (IG).

   3. Turn the tester on.

   4. Enter the following menus: Powertrain / Engine and ECT / DTC.

   5. Check if any DTCs have been stored. Note down the DTCs.

   6. Clear the DTCs Click here.

   7. Check if the MIL goes off.

      OK
      MIL goes off.

   
   

   NG

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

   OK

   REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Click here

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

   
   
   1. 

      Text in Illustration

      *a	Front view of wire harness connector (to ECM)

      Disconnect the ECM connector.

   2. Turn the power switch on (IG).

   3. Check that the MIL is not illuminated.

      OK
      MIL is not illuminated.

   4. Reconnect the ECM connector.

   
   

   NG

   CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM) Click here

   OK

   REPLACE ECM Click here

4. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)

   
   

   1. Disconnect the combination meter assembly connector.

   2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition E46-20 (EFI) or A50-36 (W) - Body ground Always 10 kΩ or higher

   4. Reconnect the combination meter assembly connector.

   5. Reconnect the ECM connector.

   
   

   NG

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

   OK

   REPLACE COMBINATION METER ASSEMBLY Click here

5. CHECK THAT ENGINE STARTS

   
   

   1. Turn the power switch on (IG).

   2. Put the engine in inspection mode Click here.

   3. Start the engine.

      Result
      Result Proceed to Engine starts A Engine cannot be put in inspection mode* (Engine cannot start) B

      Tech Tips

      *: The intelligent tester cannot communicate with the ECM.

   
   

   B

   GO TO VC OUTPUT CIRCUIT Click here

   A

6. CHECK HARNESS AND CONNECTOR (ECM TERMINAL VOLTAGE)

   
   

   1. Disconnect the ECM connector.

   2. Turn the power switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition A50-36 (W) - Body ground Power switch on (IG) 11 to 14 V

   
   

   NG

   CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM) Click here

   OK

   REPLACE ECM Click here

7. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)

   
   

   1. Disconnect the combination meter assembly connector.

   2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition E46-20 (EFI) - A50-36 (W) Always Below 1 Ω

   4. Reconnect the ECM connector.

   5. Reconnect the combination meter assembly connector.

   
   

   NG

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

   OK

   REPLACE COMBINATION METER ASSEMBLY Click here