Sfi System - Vc Output Circuit

Brand:

Toyota

Model Name:

Camry ACV40 GSV40

Manual:

Repair Manual

Section:

2Az-Fe Engine Control System

Title:

Sfi System

  1. Description

  2. Wiring diagram

  3. Inspection procedure

  4. Check mil condition

  5. Check connection between intelligent tester and ecm

  6. Check mil (throttle position sensor)

  7. Check mil (accelerator pedal position sensor)

  8. Check harness and connector

SFI SYSTEM > VC Output Circuit


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DESCRIPTION

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

Check that the Malfunction Indicator Lamp (MIL) lights up when turning the ignition switch to the ON position.OK:MIL lights up. Camry

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 for several seconds when the ignition switch is first turned to the ON position. The MIL goes off when the engine is started.

WIRING DIAGRAM


Check that the Malfunction Indicator Lamp (MIL) lights up when turning the ignition switch to the ON position.OK:MIL lights up. Camry


INSPECTION PROCEDURE

1.CHECK MIL CONDITION

  1. Check that the Malfunction Indicator Lamp (MIL) lights up when turning the ignition switch to the ON position.

    OK:
    MIL lights up.


NGnext
Go to step 2
OK
next down
SYSTEM OK

2.CHECK CONNECTION BETWEEN INTELLIGENT TESTER AND ECM

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to the ON position and turn the tester on.

  1. Check for communication between the tester and ECM.

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


Anext
GO TO MIL CIRCUIT
B
next down

3.CHECK MIL (THROTTLE POSITION SENSOR)

  1. Disconnect the C5 throttle body connector.

  1. Turn the ignition switch to the ON position.

  1. Check the MIL.

    Result:
    Result
    		Proceed to
    MIL illuminates
    		A
    MIL does not illuminate
    		B

  1. Reconnect the throttle body connector.



Anext
REPLACE THROTTLE BODY ASSEMBLY
B
next down

4.CHECK MIL (ACCELERATOR PEDAL POSITION SENSOR)

  1. Disconnect the A17 accelerator pedal position sensor connector.

  1. Turn the ignition switch to the ON position.

  1. Check the MIL.

    Result:
    Result
    		Proceed to
    MIL illuminates
    		A
    MIL does not illuminate
    		B

  1. Reconnect the accelerator pedal position sensor connector.



Anext
REPLACE ACCELERATOR PEDAL POSITION SENSOR
B
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5.CHECK HARNESS AND CONNECTOR

  1. Disconnect the C5 throttle body connector.

  1. Disconnect the A17 accelerator pedal position sensor connector.

  1. Disconnect the A24 and C24 ECM connectors. Camry

  2. Disconnect the A24 and C24 ECM connectors.

  1. Measure the resistance between the terminals of the wire harness side connectors.

    Standard resistance (Check for short):
    Tester Connection
    		Specified Condition
    VCTA (C24-67) - Body ground
    		10 kΩ or higher
    VCPA (A24-57) - Body ground
    VCP2 (A24-58) - Body ground

  1. Reconnect the throttle body connector.

  1. Reconnect the accelerator pedal position sensor connector.

  1. Reconnect the ECM connectors.



NGnext
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
next down
REPLACE ECM