Ecd System Vc Output Circuit

Engine. Lexus Is250, Is220D. Gse20 Ale20
2Ad-Fhv Engine Control System. Lexus Is250, Is220D. Gse20 Ale20

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK MIL

CHECK CONNECTION BETWEEN INTELLIGENT TESTER AND ECM

CHECK THROTTLE BODY ASSEMBLY (CHECK MIL ILLUMINATED)

CHECK ACCELERATOR PEDAL ASSEMBLY (CHECK MIL ILLUMINATED)

CHECK FUEL PRESSURE SENSOR (CHECK MIL ILLUMINATED)

CHECK EGR VALVE POSITION SENSOR (CHECK MIL ILLUMINATED)

CHECK MANIFOLD ABSOLUTE PRESSURE SENSOR (CHECK MIL ILLUMINATED)

CHECK DIFFERENTIAL PRESSURE SENSOR (CHECK MIL ILLUMINATED)

CHECK BATTERY CURRENT SENSOR ASSEMBLY (CHECK MIL ILLUMINATED)

CHECK HARNESS AND CONNECTOR

ECD SYSTEM - VC Output Circuit


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.
When the VC circuit is short-circuited, the microprocessor in the ECM 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 engine switch is first turned on (IG). The MIL goes off when the engine is started.

WIRING DIAGRAM


Lexus Is250, Is220D. Gse20 Ale20.2Ad-Fhv Engine Control System.Ecd System.Ecd System Vc Output Circuit


Lexus Is250, Is220D. Gse20 Ale20.2Ad-Fhv Engine Control System.Ecd System.Ecd System Vc Output Circuit


INSPECTION PROCEDURE

1.CHECK MIL

  1. Check that Malfunction Indicator Lamp (MIL) lights up when turning the engine switch on (IG).

    OK:
    MIL lights up.


OK
SYSTEM IS OK
NG


2.CHECK CONNECTION BETWEEN INTELLIGENT TESTER AND ECM

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG) and tester ON.

  1. Check the communication between the tester and ECM.

    Result:

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


A
GO TO MIL CIRCUIT
B


3.CHECK THROTTLE BODY ASSEMBLY (CHECK MIL ILLUMINATED)

  1. Disconnect the throttle body connector.

  1. Turn the engine switch on (IG).

  1. Check the MIL.

    Result:

    Result
    		Proceed to
    MIL illuminates
    		A
    MIL does not illuminate
    		B

  1. Reconnect the throttle body connector.



A
REPLACE THROTTLE BODY ASSEMBLY
B


4.CHECK ACCELERATOR PEDAL ASSEMBLY (CHECK MIL ILLUMINATED)

  1. Disconnect the accelerator pedal position sensor connector.

  1. Turn the engine switch on (IG).

  1. Check the MIL.

    Result:

    Result
    		Proceed to
    MIL illuminates
    		A
    MIL does not illuminate
    		B

  1. Reconnect the accelerator pedal position sensor connector.



A
REPLACE ACCELERATOR PEDAL ASSEMBLY
B


5.CHECK FUEL PRESSURE SENSOR (CHECK MIL ILLUMINATED)

  1. Disconnect the fuel pressure sensor connector.

  1. Turn the engine switch on (IG).

  1. Check the MIL.

    Result:

    Result
    		Proceed to
    MIL illuminates
    		A
    MIL does not illuminate
    		B

  1. Reconnect the fuel pressure sensor connector.



A
REPLACE FUEL PRESSURE SENSOR
B


6.CHECK EGR VALVE POSITION SENSOR (CHECK MIL ILLUMINATED)

  1. Disconnect the EGR valve position sensor connector.

  1. Turn the engine switch on (IG).

  1. Check the MIL.

    Result:

    Result
    		Proceed to
    MIL illuminates
    		A
    MIL does not illuminate
    		B

  1. Reconnect the EGR valve position sensor connector.



A
REPLACE EGR VALVE ASSEMBLY
B


7.CHECK MANIFOLD ABSOLUTE PRESSURE SENSOR (CHECK MIL ILLUMINATED)

  1. Disconnect the manifold absolute pressure sensor connector.

  1. Turn the engine switch on (IG).

  1. Check the MIL.

    Result:

    Result
    		Proceed to
    MIL illuminates
    		A
    MIL does not illuminate
    		B

  1. Reconnect the manifold absolute pressure sensor connector.



A
REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR
B


8.CHECK DIFFERENTIAL PRESSURE SENSOR (CHECK MIL ILLUMINATED)

  1. Disconnect the differential pressure sensor connector.

  1. Turn the engine switch on (IG).

  1. Check the MIL.

    Result:

    Result
    		Proceed to
    MIL illuminates
    		A
    MIL does not illuminate
    		B

  1. Reconnect the differential pressure sensor connector.



A
REPLACE DIFFERENTIAL PRESSURE SENSOR
B


9.CHECK BATTERY CURRENT SENSOR ASSEMBLY (CHECK MIL ILLUMINATED)

  1. Disconnect the battery current sensor connector.

  1. Turn the engine switch on (IG).

  1. Check the MIL.

    Result:

    Result
    		Proceed to
    MIL illuminates
    		A
    MIL does not illuminate
    		B

  1. Reconnect the battery current sensor connector.



A
REPLACE BATTERY CURRENT SENSOR ASSEMBLY
B


10.CHECK HARNESS AND CONNECTOR


    Lexus Is250, Is220D. Gse20 Ale20.2Ad-Fhv Engine Control System.Ecd System.Ecd System Vc Output Circuit

  1. Disconnect the throttle body connector.

  1. Disconnect the accelerator pedal position sensor connector.

  1. Disconnect the EGR valve position sensor connector.

  1. Disconnect the manifold absolute pressure sensor connector.

  1. Disconnect the differential pressure sensor connector.

  1. Disconnect the fuel pressure sensor connector.

  1. Disconnect the battery current sensor connector.

  1. Disconnect the E59 and A49 ECM connectors.

  1. Check the resistance.

    Standard resistance (Check for short):
    Tester Connections
    		Specified Conditions
    VCS (E59-68) - Body ground
    		10 kΩ or higher
    VCM (E59-69) - Body ground
    VCIB (E59-70) - Body ground
    VCPM (E59-71) - Body ground
    VCEG (E59-72) - Body ground
    VCPA (A49-55) - Body ground
    VCP2 (A49-56) - Body ground
    VCVL (E59-73) - Body ground
    VCPX (E59-74) - Body ground

  1. Reconnect the ECM connectors.

  1. Reconnect the fuel pressure sensor connector.

  1. Reconnect the battery current sensor connector.

  1. Reconnect the differential pressure sensor connector.

  1. Reconnect the manifold absolute pressure sensor connector.

  1. Reconnect the EGR position sensor connector.

  1. Reconnect the accelerator pedal position sensor connector.

  1. Reconnect the throttle body connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE ECM