SFI SYSTEM MIL Circuit

DESCRIPTION

The Malfunction Indicator Lamp (MIL) is used to indicate vehicle malfunctions detected by the ECM. By turning the engine switch 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 engine switch is turned on (IG), the MIL should be illuminate and should turn off after engine is started. If the MIL remains illuminated or is not illuminate, conduct the following troubleshooting procedure. If the ECM detects any trouble, the MIL illuminates. At this time, the ECM records a DTC in the memory.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. CHECK THAT MIL ILLUMINATES

   
   

   1. Turn the engine switch on (IG).

   2. Check the illumination of the MIL.

      Result
      Result Proceed to MIL remains on (Illuminate at all) A MIL remains off (Does not illuminate at all) B MIL illuminates, but turns off after engine is started C

   
   

   B

   CHECK IF 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 engine switch on (IG).

   3. Turn the tester on.

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

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

   6. Clear the DTCs Click here.

   7. Check if the MIL goes off.

      Result
      Result Proceed to MIL goes off A MIL does not go off B

   
   

   B

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

   A

   REPAIR CIRCUIT INDICATED BY OUTPUT DTC

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

   
   
   1. 

      Text in Illustration

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

      Disconnect the ECM connector.

   2. Turn the engine switch on (IG).

   3. Check if the MIL is illuminated.

      Result
      Result Proceed to MIL is not illuminated A MIL is illuminated B

   4. Reconnect the ECM connector.

   
   

   B

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

   A

   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 F16-21 (CHK) or A43-24 (W) - Body ground Always 10 kΩ or higher

      Text in Illustration

      *1

      Front view of wire harness connector (to Combination Meter Assembly)

      *2

      Front view of wire harness connector (to ECM)

   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 IF ENGINE STARTS

   
   

   1. Start the engine.

      Result
      Result Proceed to Engine starts A Engine does not 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. 

      Text in Illustration

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

      Disconnect the ECM connector.

   2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition A43-24 (W) - Body ground Engine switch on (IG) 11 to 14 V

   4. Reconnect the ECM connector.

   
   

   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 F16-21 (CHK) - A43-24 (W) Always Below 1 Ω

      Text in Illustration

      *1

      Front view of wire harness connector (to Combination Meter Assembly)

      *2

      Front view of wire harness connector (to ECM)

   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