Toyota Venza: VC Output Circuit

Toyota Venza Service Manual / 1ar-fe Engine Control / Sfi System / VC Output Circuit

DESCRIPTION

The ECM constantly generates 5 V of power from battery voltage supplied to the +B (BATT) terminal to operate the microprocessor. The ECM also provides this power to the sensors through the VC output circuit.

When the VC circuit is short-circuited, the microprocessor in the ECM and sensors that are supplied with 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 when the ignition switch is turned to ON. The MIL turns off when the engine is started.

WIRING DIAGRAM

PROCEDURE

CHECK MIL

(a) Check that the Malfunction Indicator Lamp (MIL) turns on when turning the ignition switch to ON.

OK:

MIL turns on.

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

2.	CHECK COMMUNICATION BETWEEN TECHSTREAM AND ECM

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Check the communication between the Techstream and ECM.

Result	Proceed to
Communication is not possible	A
Communication is possible	B

GO TO MIL CIRCUIT

3.	CHECK MIL (THROTTLE POSITION SENSOR)

(a) Disconnect the throttle body connector.

(b) Turn the ignition switch to ON.

Result	Proceed to
MIL does not illuminate	A
MIL illuminates	B

HINT:

Perform "Inspection After Repair" after replacing the throttle body (See page ).

REPLACE THROTTLE BODY

4.	CHECK MIL (ACCELERATOR PEDAL SENSOR ASSEMBLY)

(a) Disconnect the accelerator pedal sensor assembly connector.

(b) Turn the ignition switch to ON.

Result	Proceed to
MIL does not illuminate	A
MIL illuminates	B

REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY

5.	CHECK MIL (CANISTER PUMP MODULE)

(a) Disconnect the canister pump module connector.

(b) Turn the ignition switch to ON.

Result	Proceed to
MIL does not illuminate	A
MIL illuminates	B

REPLACE CHARCOAL CANISTER ASSEMBLY

6.	CHECK MIL (CAMSHAFT POSITION SENSOR (FOR INTAKE CAMSHAFT))

(a) Disconnect the camshaft position sensor (for intake camshaft) connector.

(b) Turn the ignition switch to ON.

Result	Proceed to
MIL does not illuminate	A
MIL illuminates	B

REPLACE CAMSHAFT POSITION SENSOR

7.	CHECK MIL (CAMSHAFT POSITION SENSOR (FOR EXHAUST CAMSHAFT))

(a) Disconnect the camshaft position sensor (for exhaust camshaft) connector.

(b) Turn the ignition switch to ON.

Result	Proceed to
MIL does not illuminate	A
MIL illuminates	B

REPLACE CAMSHAFT POSITION SENSOR

8.	CHECK MIL (INTAKE AIR CONTROL VALVE ACTUATOR)

(a) Disconnect the intake air control valve actuator connector.

(b) Turn the ignition switch to ON.

Result	Proceed to
MIL does not illuminate	A
MIL illuminates	B

REPLACE INTAKE AIR CONTROL VALVE ACTUATOR

9.	CHECK HARNESS AND CONNECTOR (VC CIRCUIT)

(a) Disconnect the throttle body connector.

(b) Disconnect the accelerator pedal sensor assembly connector.

(d) Disconnect the camshaft position sensor (for intake camshaft) connector.

(e) Disconnect the camshaft position sensor (for exhaust camshaft) connector.

(f) Disconnect the intake air control valve actuator connector.

(g) Disconnect the ECM connectors.

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

Standard Resistance (Check for Short):

Tester Connection	Condition	Specified Condition
A49-57 (VCPA) - Body ground	Always	10 kΩ or higher
A49-58 (VCP2) - Body ground	Always	10 kΩ or higher
B58-72 (VCIA) - Body ground	Always	10 kΩ or higher
B58-88 (VCTA) - Body ground	Always	10 kΩ or higher
B58-98 (VCE1) - Body ground	Always	10 kΩ or higher
B58-99 (VCV1) - Body ground	Always	10 kΩ or higher
B58-113 (VCPP) - Body ground	Always	10 kΩ or higher

REPLACE ECM

REPAIR OR REPLACE HARNESS OR CONNECTOR

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