SFI SYSTEM > MIL Circuit

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DESCRIPTION

The MIL (Malfunction Indicator Lamp) is used to indicate the detection of vehicle malfunctions 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 Techstream.

WIRING DIAGRAM


A161385E01


INSPECTION PROCEDURE

1.CHECK WHETHER MIL IS ILLUMINATED

  1. Perform troubleshooting in accordance with the table below.

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


B
Go to step 5
A


2.CHECK WHETHER MIL TURNS OFF

  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON and turn the Techstream on.

  1. Check if DTCs have been stored (Click here).
    If DTCs are output, write them down.

  1. Clear the DTCs (Click here).

  1. Check that the MIL turns off.

    OK:
    MIL turns off.


NG
Go to step 3
OK

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS 

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

  1. Disconnect the ECM connector.

  1. Turn the ignition switch to ON.

  1. Check that the MIL is not illuminated.

    OK:
    MIL is not illuminated.


NG
Go to step 4
OK

REPLACE ECM (Click here)  

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

  1. Disconnect the ECM connector.

  1. Disconnect the combination meter assembly connector.

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

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    J28-5 (CHK) or A24-24 (W) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE COMBINATION METER ASSEMBLY (Click here)  

5.CHECK THAT MIL IS ILLUMINATED

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

    OK:
    MIL illuminates.


NG
Go to step 6
OK

SYSTEM OK 

6.CHECK THAT ENGINE STARTS

  1. Turn the ignition switch to ON.

  1. Start the engine.

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

    HINT:
    *: The Techstream cannot communicate with the ECM.


B
GO TO VC OUTPUT CIRCUIT (Click here)
A


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

  1. Disconnect the ECM connector.

  1. Disconnect the combination meter assembly connector.

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

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    J28-5 (CHK) - A24-24 (W)
    		Always
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE COMBINATION METER ASSEMBLY (Click here)