MIL Circuit

2ZR-FXE ENGINE CONTROL: SFI SYSTEM: MIL Circuit
- MIL Circuit

DESCRIPTION

The MIL (Malfunction Indicator Lamp) is used to indicate vehicle malfunction detected 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 first turned on (IG), the MIL should illuminate 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) Turn the power 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 WHETHER MIL TURNS OFF

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

(e) Check if any DTCs have been stored. Note down the DTCs.

(f) Clear the DTCs DTC Check / Clear.

(g) 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 Engine Control System - SFI System

3. CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT IN WIRE HARNESS)

(a) Disconnect the ECM connector.





Text in Illustration





(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.

NG -- CHECK HARNESS AND CONNECTOR (NO. 3 METER CIRCUIT PLATE - ECM)

OK -- REPLACE ECM Removal

4. CHECK HARNESS AND CONNECTOR (NO. 3 METER CIRCUIT PLATE - ECM)

(a) Disconnect the No. 3 meter circuit plate connector.





(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Short):





Text in Illustration





(d) Reconnect the No. 3 meter circuit plate connector.

(e) Reconnect the ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 3 METER CIRCUIT PLATE - ECM)

OK -- REPLACE NO. 3 METER CIRCUIT PLATE Disassembly

5. CHECK THAT ENGINE STARTS

(a) Turn the power switch on (IG).

(b) Put the engine in inspection mode Component Tests and General Diagnostics.

(c) Start the engine.

Result:





HINT
*: The Techstream cannot communicate with the ECM.

B -- GO TO VC OUTPUT CIRCUIT
A -- Continue to next step.

6. CHECK HARNESS AND CONNECTOR (ECM TERMINAL VOLTAGE)

(a) Disconnect the ECM connector.





(b) Turn the power switch on (IG).

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





Text in Illustration





NG -- CHECK HARNESS AND CONNECTOR (NO. 3 METER CIRCUIT PLATE - ECM)

OK -- REPLACE ECM Removal

7. CHECK HARNESS AND CONNECTOR (NO. 3 METER CIRCUIT PLATE - ECM)

(a) Disconnect the No. 3 meter circuit plate connector.





(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Open):





Text in Illustration





(d) Reconnect the ECM connector.

(e) Reconnect the No. 3 meter circuit plate connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 3 METER CIRCUIT PLATE - ECM)

OK -- REPLACE NO. 3 METER CIRCUIT PLATE Disassembly