DTC P25B4-73: Turbocharger/Supercharger Wastegate "A" Actuator Stuck Closed [10/2022 - ]: Procedure

WARNING: This page is about a different car, the 2025 Lexus RX 350, 2024 Lexus RX 350, and 2023 Lexus RX 350. However, it is still accessible from the selected car via links, so may be relevant.

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P25B4-73)

Read the DTCs.

Powertrain > Engine > Trouble Codes

Result

Result	Proceed to
P25B4-73 and other DTCs are output	A
P25B4-73 is output	B

HINT:

If any DTCs other than P25B4-73 are output, troubleshoot those DTCs first.

Result:

GO TO DTC CHART. Refer to DIAGNOSTIC TROUBLE CODE CHART [10/2022 - 08/2023] , or Refer to DIAGNOSTIC TROUBLE CODE CHART [08/2023 - 10/2024] , or Refer to DIAGNOSTIC TROUBLE CODE CHART [10/2024 - ]

Result:

See step 2

CHECK VACUUM REGULATING VALVE ASSEMBLY

Pre-procedure1

Disconnect the vacuum hose of the waste gate valve actuator with bracket assembly.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*1	Waste Gate Valve Actuator with Bracket Assembly

Start the engine.

Check whether the vacuum hose of the vacuum regulating valve assembly applies no suction your finger.

Vacuum hose applies no suction to finger.

Result

Proceed to
OK
NG

Post-procedure1

None.

Result:

See step 17

Result:

See step 3

INSPECT MASS AIR FLOW METER SUB-ASSEMBLY

Inspect the mass air flow meter sub-assembly, referring to On-vehicle Inspection for Mass Air Flow Meter.
Refer to ON-VEHICLE INSPECTION [10/2022 - ]
Inspect the mass air flow meter sub-assembly, referring to Inspection for Mass Air Flow Meter.
Refer to INSPECTION [10/2022 - ]

Inspect the operation of the mass air flow meter sub-assembly.

Start the engine.

Allow the engine to idle until Coolant Temperature reaches 75°C (167°F) or higher.

Powertrain > Engine > Data List

Tester Display
Coolant Temperature

Read Mass Air Flow Sensor while maintaining an engine speed of 3000 rpm.

Powertrain > Engine > Data List

Tester Display
Engine Speed
Mass Air Flow Sensor

Standard

GTS Display	Condition	Specified Condition
Mass Air Flow Sensor	Engine warmed up Shift lever position: P A/C: Off Engine Speed: 3000 rpm	Between 5 and 15 gm/sec

Result

Proceed to
OK
NG

Result:

See step 14

Result:

See step 4

INSPECT NO. 2 TURBO PRESSURE SENSOR
Refer to PROCEDURE - Step 1

Result

Proceed to

OK

NG

Result:

NG

See step 9

Result:

OK

See step 5
REPLACE TURBOCHARGER SUB-ASSEMBLY
HINT:

Refer to REMOVAL [10/2022 - ]

Result

Proceed to

NEXT

Result:

NEXT

See step 6

CLEAR DTC

Pre-procedure1

None.

Clear the DTCs.

Powertrain > Engine > Clear DTCs

Result

Proceed to
NEXT

Post-procedure1

Turn the ignition switch off and wait for at least 30 seconds.

Result:

See step 7

CHECK WHETHER DTC OUTPUT RECURS (DTC P25B4-73)

Pre-procedure1

Start the engine and warm it up.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

Check the DTC judgment result.

Powertrain > Engine > Utility

Tester Display
All Readiness

Input the DTC: P25B4-73.

Result

Result	Proceed to
NORMAL (DTCs are not output)	A
ABNORMAL (DTC P25B4-73 is output)	B

Post-procedure1

None.

Result:

CHECK FOR INTERMITTENT PROBLEMS. Refer to CHECK FOR INTERMITTENT PROBLEMS [10/2022 - ]

Result:

See step 8

REPLACE ECM
HINT:

Refer to REMOVAL [10/2022 - ]

Result

Proceed to

NEXT

Result:

NEXT

See step 19

CHECK TERMINAL VOLTAGE (POWER SOURCE OF NO. 2 TURBO PRESSURE SENSOR)

Pre-procedure1

Disconnect the No. 2 turbo pressure sensor connector.
Turn the ignition switch to ON.

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

Standard Voltage

Tester Connection	Condition	Specified Condition	Result
B44-3 (VC) - B44-2 (E2)	Ignition switch ON	4.5 to 5.5 V	V
B44-1 (PTA) - B44-2 (E2)	Ignition switch ON	3.0 to 5.0 V	V

Result

Proceed to
OK
NG

Post-procedure1

None.

Result:

See step 11

Result:

See step 10

REPLACE NO. 2 TURBO PRESSURE SENSOR
HINT:

Refer to PROCEDURE - Step 3

Result

Proceed to

NEXT

Result:

NEXT

See step 19

CHECK HARNESS AND CONNECTOR (NO. 2 TURBO PRESSURE SENSOR - ECM)

Pre-procedure1

Disconnect the No. 2 turbo pressure sensor connector.
Disconnect the ECM connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition	Result
B44-3 (VC) - B27-102 (VPTA)	Always	Below 1 Ω	Ω
B44-2 (E2) - B27-125 (EPTA)	Always	Below 1 Ω	Ω
B44-1 (PTA) - B27-126 (PTA)	Always	Below 1 Ω	Ω
B44-3 (VC) or B27-102 (VPTA) - Body ground and other terminals	Always	10 kΩ or higher	kΩ
B44-1 (PTA) or B27-126 (PTA) - Body ground and other terminals	Always	10 kΩ or higher	kΩ

Result

Proceed to
OK
NG

Post-procedure1

None.

Result:

See step 13

Result:

See step 12

REPLACE ECM
HINT:

Refer to REMOVAL [10/2022 - ]

Result

Proceed to

NEXT

Result:

NEXT

See step 19

REPAIR OR REPLACE HARNESS OR CONNECTOR

Repair or replace the wire harness or connector.

Result

Proceed to
NEXT

Result:

See step 19

CHECK TERMINAL VOLTAGE (POWER SOURCE OF MASS AIR FLOW METER SUB-ASSEMBLY)

Pre-procedure1

Disconnect the mass air flow meter sub-assembly connector.
Turn the ignition switch to ON.

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

Standard Voltage

Tester Connection	Condition	Specified Condition	Result
B14-3 (VCC) - B14-2 (E2G)	Ignition switch ON	4.8 to 5.2 V	V
B14-1 (FG) - B14-2 (E2G)	Ignition switch ON	4.8 to 5.2 V	V

Result

Proceed to
OK
NG

Post-procedure1

None.

Result:

See step 16

Result:

See step 15

INSPECT MASS AIR FLOW METER SUB-ASSEMBLY
Refer to ON-VEHICLE INSPECTION [10/2022 - ]

Result

Proceed to

OK

NG

Result:

OK

REPLACE ECM. Refer to REMOVAL [10/2022 - ]

Result:

NG

REPLACE MASS AIR FLOW METER SUB-ASSEMBLY. Refer to REMOVAL [10/2022 - ]

CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)

Pre-procedure1

Disconnect the mass air flow meter sub-assembly connector.
Disconnect the ECM connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition	Result
B14-3 (VCC) - B27-73 (VCVG)	Always	Below 1 Ω	Ω
B14-1 (FG) - B27-75 (VG)	Always	Below 1 Ω	Ω
B14-2 (E2G) - B27-74 (E2G)	Always	Below 1 Ω	Ω
B14-3 (VCC) or B27-73 (VCVG) - Body ground and other terminals	Always	10 kΩ or higher	kΩ
B14-1 (FG) or B27-75 (VG) - Body ground and other terminals	Always	10 kΩ or higher	kΩ
B14-2 (E2G) or B27-74 (E2G) - Body ground and other terminals	Always	10 kΩ or higher	kΩ

Result

Proceed to
OK
NG

Post-procedure1

None.

Result:

REPLACE ECM. Refer to REMOVAL [10/2022 - ]

Result:

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE VACUUM REGULATING VALVE ASSEMBLY
HINT:

Refer to REMOVAL [10/2022 - ]

Result

Proceed to

NEXT

Result:

NEXT

See step 18

CLEAR DTC

Pre-procedure1

None.

Clear the DTCs.

Powertrain > Engine > Clear DTCs

Result

Proceed to
NEXT

Post-procedure1

Turn the ignition switch off and wait for at least 30 seconds.

Result:

See step 19

CHECK WHETHER DTC OUTPUT RECURS (DTC P25B4-73)

Pre-procedure1

Start the engine and warm it up.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

Check the DTC judgment result.

Powertrain > Engine > Utility

Tester Display
All Readiness

Input the DTC: P25B4-73.

GTS Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions

Result

Proceed to
NEXT

Post-procedure1

None.

Result:

END