MIL Circuit
2GR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: MIL Circuit
- MIL Circuit
DESCRIPTION
The MIL (Malfunction Indicator Lamp) is used to indicate vehicle malfunctions detected by the ECM. By turning the ignition switch 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 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
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 Techstream to the DLC3.
(b) Start the engine and turn the Techstream on.
(c) Select the following menu items: Powertrain / Engine / Trouble Codes.
(d) Check if any DTCs have been stored. Note down any DTCs.
(e) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(f) Check if the MIL goes off.
Standard:
MIL goes off.
Result:
B -- CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT IN WIRE HARNESS)
A -- REPAIR CIRCUIT INDICATED BY OUTPUT DTC SFI System
3. CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT IN WIRE HARNESS)
(a) Disconnect the ECM connector.
(b) Turn the ignition switch to ON.
(c) Check that the MIL is not illuminated.
OK:
MIL is not illuminated.
Result:
(d) Reconnect the ECM connector.
B -- REPLACE ECM Removal
A -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)
(a) Disconnect the ECM connector.
(b) Disconnect the combination meter assembly connector.
(c) Measure the resistance.
Standard resistance (Check for short):
(d) Reconnect the ECM connector.
(e) Reconnect the combination meter assembly connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (COMBINATION METER ASSEMBLY - ECM)
OK -- REPLACE COMBINATION METER ASSEMBLY Removal
5. CHECK THAT MIL IS ILLUMINATED
(a) Check if the MIL is illuminated when the ignition switch is turned to ON.
OK:
MIL is illuminated.
Result:
B -- CHECK THAT ENGINE STARTS
A -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems
6. CHECK THAT ENGINE STARTS
(a) Turn the ignition switch to ON.
(b) Start the engine.
Result:
HINT
*: Techstream cannot communicate with the ECM.
B -- GO TO VC OUTPUT CIRCUIT VC Output Circuit
A -- Continue to next step.
7. INSPECT COMBINATION METER ASSEMBLY (MIL CIRCUIT)
(a) Check the MIL circuit Problem Symptoms Table.
NG -- REPLACE COMBINATION METER ASSEMBLY Removal
OK -- CHECK AND REPLACE HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)