MIL Circuit
2UR-GSE ENGINE CONTROL: 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 engine 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 engine 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) Turn the engine switch on (IG).
(b) Check the illumination of the MIL.
Result:
C -- SYSTEM OK
B -- CHECK THAT ENGINE STARTS
A -- Continue to next step.
2. CHECK IF MIL TURNS OFF
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG) and turn the Techstream on.
(c) Check if DTCs have been stored Reading and Clearing Diagnostic Trouble Codes. If DTCs are present, write them down.
(d) Clear DTCs Reading and Clearing Diagnostic Trouble Codes.
(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 SFI System
3. CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT IN WIRE HARNESS)
(a) Disconnect the ECM connector.
(b) Turn the engine switch on (IG).
(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 - ECM)
OK -- REPLACE ECM Removal
4. CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM)
(a) Disconnect the combination meter connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Short):
(d) Reconnect the combination meter connector and ECM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPAIR OR REPLACE COMBINATION METER Removal
5. CHECK THAT ENGINE STARTS
(a) Start the engine.
Result:
HINT
*: The Techstream cannot communicate with the ECM.
B -- GO TO VC OUTPUT CIRCUIT VC Output Circuit
A -- Continue to next step.
6. CHECK HARNESS AND CONNECTOR (ECM TERMINAL VOLTAGE)
(a) Disconnect the ECM connector.
(b) Turn the engine switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
(d) Reconnect the ECM connector.
NG -- CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM)
OK -- REPLACE ECM Removal
7. CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM)
(a) Disconnect the combination meter connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
(d) Reconnect the combination meter connector and ECM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE COMBINATION METER ASSEMBLY Removal