Land Cruiser URJ200 URJ202 GRJ200 VDJ200 - 1VD-FTV ENGINE CONTROL

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).	Turbocharger sub-assembly Turbo motor driver Turbo motor driver power source VN turbo link stuck malfunction Extremely low battery voltage (P0560 stored simultaneously) ECM

Related Data List
DTC No.	Data List
P1251	MAP Target Booster Pressure

If DTC P1251 is stored, the following symptoms may appear:

VN turbo vane stuck closed malfunction

Vehicle surge when driving with full load

Sudden lack of power due to power being limited

WIRING DIAGRAM

Refer to DTC P0046 ().

Refer to DTC P00AF ().

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 () and initialization ( ).

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

Connect the intelligent tester to the DLC3.

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

Enter the following menus: Powertrain / Engine / DTC.

Read the DTCs.

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

GO TO DTC CHART ()

A

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

Dtc P1251 Turbocharger / Supercharger Overboost Condition (Too High). 1VD-FTV ENGINE CONTROL. Land Cruiser URJ200 URJ202 GRJ200 VDJ200

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.

Go to step 4

OK

3.CHECK WHETHER DTC OUTPUT RECURS (DTC P1251)

Connect the intelligent tester to the DLC3.

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

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

Clear DTCs ().

Turn the ignition switch off.

Start the engine and warm it up.

Drive the vehicle.

Enter the following menus: Powertrain / Engine / DTC.

Read the DTCs.

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

Go to step 11

END

4.INSPECT TURBO MOTOR DRIVER (POWER SOURCE CIRCUIT)

Disconnect the turbo motor driver connector.

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

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

Go to step 10

OK

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

Disconnect the turbo motor driver connector.

Disconnect the ECM connector.

Dtc P1251 Turbocharger / Supercharger Overboost Condition (Too High). 1VD-FTV ENGINE CONTROL. Land Cruiser URJ200 URJ202 GRJ200 VDJ200

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

Go to step 10

OK

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

Disconnect the DC motor (for Bank 1) connector.

Disconnect the DC motor (for Bank 2) connector.

Disconnect the turbo motor driver connector.

Dtc P1251 Turbocharger / Supercharger Overboost Condition (Too High). 1VD-FTV ENGINE CONTROL. Land Cruiser URJ200 URJ202 GRJ200 VDJ200

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

Go to step 10

OK

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

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

NEXT

8.CHECK WHETHER DTC OUTPUT RECURS (DTC P1251)

Connect the intelligent tester to the DLC3.

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

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

Clear the DTCs ().

Turn the ignition switch off.

Start the engine and warm it up.

Drive the vehicle.

Enter the following menus: Powertrain / Engine / DTC.

Read the DTCs.

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

END

A

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

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

Go to step 12

10.REPAIR OR REPLACE HARNESS OR CONNECTOR

Go to step 12

11.REPLACE ECM

Replace the ECM ().

NEXT

12.CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

Connect the intelligent tester to the DLC3.

Clear the DTCs ().

Turn the ignition switch off.

Start the engine and warm it up.

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

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.

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

Input DTC P1251.

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.

END

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