Malfunction Indicator Lamp: Testing and Inspection

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

DESCRIPTION

The MIL (Malfunction Indicator Lamp) is used to indicate vehicle malfunction detected by the hybrid vehicle control ECU. When the power switch is turned on (IG), power is supplied to the MIL circuit, and the hybrid vehicle control ECU 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 SFI System

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

(a) Disconnect the hybrid vehicle control ECU 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 hybrid vehicle control ECU connector.

NG -- CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - HYBRID VEHICLE CONTROL ECU)

OK -- REPLACE HYBRID VEHICLE CONTROL ECU Removal

4. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - HYBRID VEHICLE CONTROL ECU)

(a) Disconnect the combination meter assembly connector.

(b) Disconnect the hybrid vehicle control ECU connector.

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

Standard Resistance (Check for Short):





(d) Reconnect the combination meter assembly connector.

(e) Reconnect the hybrid vehicle control ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE COMBINATION METER ASSEMBLY Removal

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 hybrid vehicle control ECU.

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

6. CHECK COMBINATION METER ASSEMBLY (TERMINAL VOLTAGE)

(a) Disconnect the hybrid vehicle control ECU 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





(d) Reconnect the hybrid vehicle control ECU connector.

NG -- CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - HYBRID VEHICLE CONTROL ECU)

OK -- REPLACE HYBRID VEHICLE CONTROL ECU Removal

7. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - HYBRID VEHICLE CONTROL ECU)

(a) Disconnect the combination meter assembly connector.

(b) Disconnect the hybrid vehicle control ECU connector.

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

Standard Resistance (Check for Open):





(d) Reconnect the hybrid vehicle control ECU connector.

(e) Reconnect the combination meter assembly connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE COMBINATION METER ASSEMBLY Removal