SFI SYSTEM(w/ EGR System) MIL Circuit

DESCRIPTION

The Malfunction Indicator Lamp (MIL) is used to indicate vehicle malfunctions detected by the ECM. By turning the power 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 power switch is first turned on (IG), the MIL should be illuminated and should then turn off after engine is started. If the MIL remains illuminated or is not illuminated, 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

*a	Combination Meter Assembly

PROCEDURE

1. CHECK THAT MIL ILLUMINATES

   
   

   1. Turn the power switch on (IG).

   2. Check the illumination of the MIL.

      Result
      Result Proceed to MIL remains illuminated (Even after power switch is turned to 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 IF ENGINE STARTS Click here

   C

   CHECK FOR INTERMITTENT PROBLEMS Click here

   A

2. CHECK WHETHER MIL TURNS OFF

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the power switch on (IG).

   3. Turn the GTS on.

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

   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

   
   

   A

   REPAIR CIRCUIT INDICATED BY OUTPUT DTC Click here

   B

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

   
   

   1. 

      Disconnect the ECM connector.

   2. Turn the power 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.

   
   

   A

   REPLACE ECM Click here

   B

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
      Tester Connection Condition Specified Condition N40-5 (CHK) or A79-30 (W) - Body ground Always 10 kΩ or higher

   4. Reconnect the combination meter assembly connector.

   5. Reconnect the ECM connector.

   
   

   OK

   REPLACE COMBINATION METER ASSEMBLY Click here

   NG

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

5. CHECK IF ENGINE STARTS

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the power switch on (IG).

   3. Turn the GTS on.

   4. Put the engine in inspection mode (maintenance mode) Click here.

   5. Start the engine.

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

      Tech Tips

      *: The GTS 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 A79-30 (W) - Body ground Power switch on (IG) 11 to 14 V

   4. Reconnect the ECM connector.

   
   

   OK

   REPLACE ECM Click here

   NG

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
      Tester Connection Condition Specified Condition N40-5 (CHK) - A79-30 (W) Always Below 1 Ω

   4. Reconnect the ECM connector.

   5. Reconnect the combination meter assembly connector.

   
   

   OK

   REPLACE COMBINATION METER ASSEMBLY Click here

   NG

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