Dtc P1251 Turbocharger / Supercharger Overboost Condition (Too High)

Engine Hybrid System. Land Cruiser. Urj200, 202 Grj200 Vdj200
1Vd-Ftv Engine Control. Land Cruiser. Urj200, 202 Grj200 Vdj200

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P1251)

INSPECT TURBOCHARGER SUB-ASSEMBLY (for Bank 1 and/or Bank 2)

CHECK WHETHER DTC OUTPUT RECURS (DTC P1251)

INSPECT TURBO MOTOR DRIVER (POWER SOURCE CIRCUIT)

CHECK HARNESS AND CONNECTOR (TURBO MOTOR DRIVER - ECM)

CHECK HARNESS AND CONNECTOR (DC MOTOR - TURBO MOTOR DRIVER)

REPLACE TURBO MOTOR DRIVER (for Bank 1 and/or Bank 2)

CHECK WHETHER DTC OUTPUT RECURS (DTC P1251)

REPLACE TURBOCHARGER SUB-ASSEMBLY (for Bank 1 and/or Bank 2) (DC MOTOR)

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE ECM

CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

DTC P1251 Turbocharger / Supercharger Overboost Condition (Too High)


DESCRIPTION

HINT:
Refer to DTC P0046 (Click here).
Refer to DTC P00AF (Click here).

P1251
DTC Detection Drive Pattern
DTC Detection Condition
Trouble Area
Vehicle being driven
The turbo motor driver detects an overcurrent caused by the DC motor being stuck (1 trip detection logic).
  1. Turbocharger sub-assembly
  2. Turbo motor driver
  3. Turbo motor driver power source
  4. VN turbo link stuck malfunction
  5. Extremely low battery voltage (P0560 stored simultaneously)
  6. ECM

Related Data List
DTC No.
Data List
P1251
  1. MAP
  2. Target Booster Pressure
If DTC P1251 is stored, the following symptoms may appear:
  1. VN turbo vane stuck closed malfunction
    1. Vehicle surge when driving with full load
    2. Sudden lack of power due to power being limited

WIRING DIAGRAM

Refer to DTC P0046 (Click here).
Refer to DTC P00AF (Click here).

INSPECTION PROCEDURE

HINT:
Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.
NOTICE:
After replacing the ECM, the new ECM needs registration (Click here) and initialization (Click here ).
1.CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P1251)

  1. Connect the intelligent tester to the DLC3.

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

  1. Enter the following menus: Powertrain / Engine / DTC.

  1. Read the DTCs.

    Result:

    Display (DTC Output)
    		Proceed to
    P1251
    		A
    P1251 and other DTCs
    		B


B
GO TO DTC CHART (Click here)
A


2.INSPECT TURBOCHARGER SUB-ASSEMBLY (for Bank 1 and/or Bank 2)
Land Cruiser. Urj200, 202 Grj200 Vdj200.1Vd-Ftv Engine Control.Ecd System (W/ Dpf). Dtc P1251 Turbocharger / Supercharger Overboost Condition (Too High)

  1. Check the motor movement when turning the ignition switch to ON, when starting the engine and then when turning the ignition switch off.

    OK:
    Motor moves as shown in the illustration.


NG
Go to step 4
OK


3.CHECK WHETHER DTC OUTPUT RECURS (DTC P1251)

  1. Connect the intelligent tester to the DLC3.

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

  1. Enter the following: Powertrain / Engine / DTC / Clear.

  1. Clear DTCs (Click here).

  1. Turn the ignition switch off.

  1. Start the engine and warm it up.

  1. Drive the vehicle.

  1. Enter the following menus: Powertrain / Engine / DTC.

  1. Read the DTCs.

    Result:

    Display (DTC Output)
    		Proceed to
    P1251
    		A
    No output
    		B


A
Go to step 11

B
END

4.INSPECT TURBO MOTOR DRIVER (POWER SOURCE CIRCUIT)


    Land Cruiser. Urj200, 202 Grj200 Vdj200.1Vd-Ftv Engine Control.Ecd System (W/ Dpf). Dtc P1251 Turbocharger / Supercharger Overboost Condition (Too High)

  1. Disconnect the turbo motor driver connector.

  1. Measure the voltage according to the value(s) in the table below.

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    A48-1 (+B) - A48-2 (GND)
    		Engine switch on (IG)
    		11 to 14 V
    A48-16 (+B2) - A48-17 (GND2)
    		Engine switch on (IG)
    		11 to 14 V

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A48-2 (GND) - Body ground
    		Always
    		Below 1 Ω
    A48-17 (GND2) - Body ground
    		Always
    		Below 1 Ω


NG
Go to step 10
OK


5.CHECK HARNESS AND CONNECTOR (TURBO MOTOR DRIVER - ECM)

  1. Disconnect the turbo motor driver connector.



  1. Disconnect the ECM connector.


    Land Cruiser. Urj200, 202 Grj200 Vdj200.1Vd-Ftv Engine Control.Ecd System (W/ Dpf). Dtc P1251 Turbocharger / Supercharger Overboost Condition (Too High)

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

    Standard Resistance (Check for Open):

    for LHD
    Tester Connection
    		Condition
    		Specified Condition
    C45-49 (VNTO) - A48-5 (VNTO)
    		Always
    		Below 1 Ω
    C45-50 (VNTI) - A48-4 (VNTI)
    		Always
    		Below 1 Ω
    C45-47 (VNO2) - A48-20 (VNO2)
    		Always
    		Below 1 Ω
    C45-48 (VNI2) - A48-11 (VNI2)
    		Always
    		Below 1 Ω

    for RHD
    Tester Connection
    		Condition
    		Specified Condition
    C46-49 (VNTO) - A48-5 (VNTO)
    		Always
    		Below 1 Ω
    C46-50 (VNTI) - A48-4 (VNTI)
    		Always
    		Below 1 Ω
    C46-47 (VNO2) - A48-20 (VNO2)
    		Always
    		Below 1 Ω
    C46-48 (VNI2) - A48-11 (VNI2)
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):

    for LHD
    Tester Connection
    		Condition
    		Specified Condition
    C45-49 (VNTO) or A48-5 (VNTO) - Body ground
    		Always
    		10 kΩ or higher
    C45-50 (VNTI) or A48-4 (VNTI) - Body ground
    		Always
    		10 kΩ or higher
    C45-47 (VNO2) or A48-20 (VNO2) - Body ground
    		Always
    		10 kΩ or higher
    C45-48 (VNI2) or A48-11 (VNI2) - Body ground
    		Always
    		10 kΩ or higher

    for RHD
    Tester Connection
    		Condition
    		Specified Condition
    C46-49 (VNTO) or A48-5 (VNTO) - Body ground
    		Always
    		10 kΩ or higher
    C46-50 (VNTI) or A48-4 (VNTI) - Body ground
    		Always
    		10 kΩ or higher
    C46-47 (VNO2) or A48-20 (VNO2) - Body ground
    		Always
    		10 kΩ or higher
    C46-48 (VNI2) or A48-11 (VNI2) - Body ground
    		Always
    		10 kΩ or higher


NG
Go to step 10
OK


6.CHECK HARNESS AND CONNECTOR (DC MOTOR - TURBO MOTOR DRIVER)

  1. Disconnect the DC motor (for Bank 1) connector.

  1. Disconnect the DC motor (for Bank 2) connector.



  1. Disconnect the turbo motor driver connector.


    Land Cruiser. Urj200, 202 Grj200 Vdj200.1Vd-Ftv Engine Control.Ecd System (W/ Dpf). Dtc P1251 Turbocharger / Supercharger Overboost Condition (Too High)

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

    Standard Resistance (Check for Open):

    for Bank 1
    Tester Connection
    		Condition
    		Specified Condition
    C90-1 (M-) - A48-10 (M-)
    		Always
    		Below 1 Ω
    C90-2 (M+) - A48-3 (M+)
    		Always
    		Below 1 Ω

    for Bank 2
    Tester Connection
    		Condition
    		Specified Condition
    z67-1 (M2-) - A48-19 (M2-)
    		Always
    		Below 1 Ω
    z67-2 (M2+) - A48-18 (M2+)
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):

    for Bank 1
    Tester Connection
    		Condition
    		Specified Condition
    C90-1 (M-) or A48-10 (M-) - Body ground
    		Always
    		10 kΩ or higher
    C90-2 (M+) or A48-3 (M+) - Body ground
    		Always
    		10 kΩ or higher

    for Bank 2
    Tester Connection
    		Condition
    		Specified Condition
    z67-1 (M2-) or A48-19 (M2-) - Body ground
    		Always
    		10 kΩ or higher
    z67-2 (M2+) or A48-18 (M2+) - Body ground
    		Always
    		10 kΩ or higher


NG
Go to step 10
OK


7.REPLACE TURBO MOTOR DRIVER (for Bank 1 and/or Bank 2)

  1. Replace the turbo motor driver (for Bank 1 and/or Bank 2) (Click here).


NEXT


8.CHECK WHETHER DTC OUTPUT RECURS (DTC P1251)

  1. Connect the intelligent tester to the DLC3.

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

  1. Enter the following menus: Powertrain / Engine / DTC / Clear.

  1. Clear the DTCs (Click here).

  1. Turn the ignition switch off.

  1. Start the engine and warm it up.

  1. Drive the vehicle.

  1. Enter the following menus: Powertrain / Engine / DTC.

  1. Read the DTCs.

    Result
    Display (DTC Output)
    		Proceed to
    P1251
    		A
    No output
    		B


B
END
A


9.REPLACE TURBOCHARGER SUB-ASSEMBLY (for Bank 1 and/or Bank 2) (DC MOTOR)

  1. Replace the turbocharger sub-assembly (for Bank 1 or Bank 2) (Click here).



NEXT
Go to step 12

10.REPAIR OR REPLACE HARNESS OR CONNECTOR


NEXT
Go to step 12

11.REPLACE ECM

  1. Replace the ECM (Click here).


NEXT


12.CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

  1. Connect the intelligent tester to the DLC3.

  1. Clear the DTCs (Click here).

  1. Turn the ignition switch off.

  1. Start the engine and warm it up.

  1. Run the engine with a heavy load at a mid to high engine speed.

  1. Confirm that the DTC is not output again.

    HINT:
    Perform the following procedure using the tester to determine whether or not the DTC judgment has been carried out.

    1. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

    2. Input DTC P1251.

    3. Check that STATUS is NORMAL. If STATUS is INCOMPLETE or UNKNOWN, increase the time spent running the engine with a heavy load at a mid to high engine speed.


NEXT

END