MIL Circuit

2UR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: MIL Circuit

MIL Circuit

DESCRIPTION

The MIL (Malfunction Indicator Lamp) is used to indicate vehicle malfunction detections 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. If the MIL remains illuminated or is not illuminated, conduct the following troubleshooting procedure.
If the ECM detects trouble, the MIL illuminates. At this time, the ECM records a DTC in the memory.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK THAT MIL IS ILLUMINATED
(a) Perform troubleshooting in accordance with the chart below.

Result





B -- CHECK THAT MIL IS ILLUMINATED
A -- Continue to next step.
2. CHECK IF MIL TURNS OFF
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch ON (IG) and turn the Techstream ON.
(c) Check if DTCs have been stored DTC Check / Clear. If DTCs are present, write them down.
(d) Clear the DTCs DTC Check / Clear.
(e) Check that the MIL turns off.
OK:
MIL turns off.
NG -- CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT IN WIRE HARNESS)
OK -- REPAIR CIRCUITS INDICATED BY OUTPUT DTCS
3.
CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT IN WIRE HARNESS)




(a) Disconnect the A14 ECM connector.
(b) Turn the power switch ON (IG).
(c) Check that the MIL is not illuminated.
OK:
MIL is not illuminated.
NG -- CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM)
OK -- REPLACE ECM
4.
CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM)




(a) Disconnect the L10 combination meter connector.
(b) Disconnect the A14 ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance (check for open):






Standard resistance (check for short):






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPAIR OR REPLACE COMBINATION METER
5. CHECK THAT MIL IS ILLUMINATED
(a) Check if the MIL is illuminated when turning the power switch ON (IG).
OK:
MIL is illuminated.
NG -- CHECK THAT ENGINE STARTS
OK -- SYSTEM OK
6. CHECK THAT ENGINE STARTS
(a) Turn the power switch ON (IG).
(b) Put the engine in inspection mode Inspection Mode Procedure.

Result





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

B -- GO TO VC OUTPUT CIRCUIT
A -- Continue to next step.
7. INSPECT COMBINATION METER ASSEMBLY (MIL CIRCUIT)
(a) See the combination meter troubleshooting procedure How To Proceed With Troubleshooting.
NG -- REPAIR OR REPLACE COMBINATION METER ASSEMBLY
OK -- CHECK AND REPAIR HARNESS OR CONNECTOR (COMBINATION METER - ECM)