VC Output Circuit

2AZ-FXE ENGINE CONTROL: SFI SYSTEM: VC Output Circuit
- VC Output Circuit

DESCRIPTION

The hybrid vehicle control ECU constantly uses 5 V from the battery voltages supplied to the +B (BATT) terminal to operate the microprocessor. The hybrid vehicle control ECU also provides this power to the sensors through the VC output circuit.





When the VC circuit is shorted, the microprocessor in the hybrid vehicle control ECU and sensors that are supplied power through the VC circuit are inactivated because the power is not supplied from the VC circuit. Under this condition, the system does not start up and the MIL does not illuminate even if the system malfunctions.

HINT
Under normal conditions, the MIL is illuminated for several seconds when the power switch is first turned on (IG). The MIL goes off when the engine is started.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK MIL

(a) Check that the Malfunction Indicator Lamp (MIL) illuminates when turning the power switch on (IG).

OK:

MIL lights up.

NG -- CHECK CONNECTION BETWEEN TECHSTREAM AND HYBRID VEHICLE CONTROL ECU

OK -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures

2. CHECK CONNECTION BETWEEN TECHSTREAM AND HYBRID VEHICLE CONTROL ECU

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

(d) Check the communication between the Techstream and hybrid vehicle control ECU.

Result:





B -- GO TO MIL CIRCUIT Testing and Inspection
A -- Continue to next step.

3. CHECK MIL (THROTTLE POSITION SENSOR)

(a) Disconnect the throttle position sensor connector.

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

(c) Check the MIL.

Result:





(d) Reconnect the throttle position sensor connector.

B -- REPLACE THROTTLE BODY ASSEMBLY Removal
A -- Continue to next step.

4. CHECK MIL (MANIFOLD ABSOLUTE PRESSURE SENSOR)

(a) Disconnect the manifold absolute pressure sensor connector.

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

(c) Check the MIL.

Result:





(d) Reconnect the manifold absolute pressure sensor connector.

B -- REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR Removal
A -- Continue to next step.

5. CHECK MIL (CANISTER PUMP MODULE)

(a) Disconnect the canister pump module connector.

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

(c) Check the MIL.

Result:





(d) Reconnect the canister pump module connector.

B -- REPLACE CANISTER Removal
A -- Continue to next step.

6. CHECK HARNESS AND CONNECTOR (THROTTLE POSITION SENSOR - HYBRID VEHICLE CONTROL ECU)

(a) Disconnect the throttle position sensor 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 throttle position sensor connector.

(e) Reconnect the hybrid vehicle control ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

7. CHECK HARNESS AND CONNECTOR (MANIFOLD ABSOLUTE PRESSURE SENSOR - HYBRID ECU)

(a) Disconnect the manifold absolute pressure sensor 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 manifold absolute pressure sensor connector.

(e) Reconnect the hybrid vehicle control ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

8. CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - HYBRID VEHICLE CONTROL ECU)

(a) Disconnect the canister pump module 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 canister pump module connector.

(e) Reconnect the hybrid vehicle control ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE HYBRID VEHICLE CONTROL ECU Removal