Malfunction Indicator Lamp: Testing and Inspection

1NZ-FXE ENGINE CONTROL SYSTEM: SFI SYSTEM: MIL Circuit

MIL Circuit

DESCRIPTION

The IG2 relay energized by the power source control ECU applies the battery voltage to the malfunction indicator lamp (MIL) in the combination meter while the main system is ON.
When it is necessary, the ECM grounds the W terminal line and illuminates the MIL.
In order to perform functional check visually, the MIL is illuminated when the power switch is first turned ON (IG).
If the MIL is ON or OFF all of the time, use the procedure below to troubleshoot it. The MIL is used to indicate a vehicle malfunction which was detected by the ECM. Follow this procedure using Techstream or the OBD II scan tool to determine the cause of the problem and to check the MIL.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK MIL CONDITION
(a) Perform troubleshooting in accordance with the chart below.
Result:






B -- CHECK THAT MIL IS ILLUMINATED
A -- Continue to next step.

2. CLEAR DTC
(a) Connect Techstream to the DLC3.
(b) Turn the power ON (IG).
(c) Turn the tester ON.
(d) Read DTCs.
(e) Clear the DTCs DTC Check / Clear.
(f) Check that the MIL is not illuminated.
OK:
MIL is not illuminated.
OK -- REPAIR CIRCUITS INDICATED BY OUTPUT DTCS
NG -- Continue to next step.

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




(a) Disconnect the E6 ECM connector.
(b) Turn the power switch ON (IG).
(c) Check that the MIL is not illuminated.
OK:
MIL is not illuminated.
(d) Reconnect the ECM connector.
OK -- REPLACE ECM
NG -- CHECK AND REPAIR HARNESS AND CONNECTOR (COMBINATION METER - ECM)
4. CHECK THAT MIL IS ILLUMINATED
(a) Check that the MIL is illuminated when the power switch is turned ON (IG).
Standard:
MIL is illuminated.
OK -- SYSTEM OK
NG -- Continue to next step.

5. CHECK THAT ENGINE STARTS
(a) Turn the power switch ON (IG).
(b) Start the engine.
Result:





HINT: *: Techstream cannot communicate with the ECM.

B -- GO TO VC OUTPUT CIRCUIT
A -- Continue to next step.

6. INSPECT COMBINATION METER ECU (MIL CIRCUIT)
(a) See the combination meter troubleshooting How To Proceed With Troubleshooting.
NG -- REPAIR OR REPLACE BULB OR COMBINATION METER ASSEMBLY
OK -- CHECK AND REPAIR HARNESS AND CONNECTOR (COMBINATION METER - ECM)