MIL Circuit

2GR-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. When the power switch is turned 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 turned on (IG), the MIL should illuminate. Then when the power switch is turned on (READY), the MIL should turn off. If the MIL remains illuminated or is not illuminated, conduct the following troubleshooting procedure using the Techstream.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

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






B -- CHECK THAT MIL IS ILLUMINATED
A -- Continue to next step.
2. CHECK WHETHER MIL TURNS OFF
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG) and turn the Techstream on.
(c) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(d) Check if any DTCs have been stored. Note down any DTCs.
(e) Clear DTCs DTC Check / Clear.
(f) Check if the MIL goes off.
OK:
MIL should go off.
OK -- REPAIR CIRCUIT INDICATED BY OUTPUT DTC
NG -- Continue to next step.
3.
CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT IN WIRE HARNESS)




(a) Disconnect the A53 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 -- Continue to next step.
4.
CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM)




(a) Disconnect the K31 combination meter connector.
(b) Disconnect the A53 ECM connector.
(c) Measure the resistance.
Standard resistance (Check for short):





(d) Reconnect the combination meter connector.
(e) Reconnect the ECM connector.
OK -- REPAIR OR REPLACE COMBINATION METER ASSEMBLY
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
5. CHECK THAT MIL IS ILLUMINATED
(a) Check if the MIL is illuminated when the power switch is turned on (IG).
OK:
MIL should be illuminated.
OK -- SYSTEM OK
NG -- Continue to next step.
6. CHECK THAT ENGINE STARTS
(a) Turn the power switch on (IG).
(b) Start the engine.
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) Check the MIL circuit System Diagram.
NG -- REPAIR OR REPLACE COMBINATION METER ASSEMBLY
OK -- CHECK AND REPLACE HARNESS OR CONNECTOR (COMBINATION METER - ECM)