MIL Circuit
1GR-FE ENGINE CONTROL: SFI SYSTEM: MIL Circuit
- MIL Circuit
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. 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 ignition switch to ON and turn the Techstream on.
(c) Enter the following menus: Powertrain / Engine and ECT / Trouble Code.
(d) Check if any DTCs have been stored. Note down any DTCs.
(e) Clear DTCs Reading and Clearing Diagnostic Trouble Codes.
(f) Check if the MIL goes off.
OK:
MIL goes off.
NG -- CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT IN WIRE HARNESS)
OK -- REPAIR CIRCUITS INDICATED BY OUTPUT DTCS 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.
(d) Reconnect the ECM connector.
NG -- CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)
OK -- REPLACE ECM Removal
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 according to the value(s) in the table below.
Standard Resistance:
(d) Reconnect the ECM connector.
(e) Reconnect the combination meter assembly connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPAIR OR 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.
NG -- CHECK THAT ENGINE STARTS
OK -- SYSTEM OK
6. CHECK THAT ENGINE STARTS
(a) Turn the ignition switch to ON.
(b) Check that the engine starts.
Result
HINT
*: The 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) Refer to the combination meter troubleshooting procedure How To Proceed With Troubleshooting.
NG -- REPAIR OR REPLACE COMBINATION METER ASSEMBLY Removal
OK -- REPAIR OR REPLACE HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)