DTC B1422-00: A/C Inverter Load Malfunction [11/2021 - ]: Procedure
WARNING: This page is about a different car, the 2025 Lexus NX 350h, 2024 Lexus NX 350h, 2023 Lexus NX 350h, and 2022 Lexus NX 350h. However, it is still accessible from the selected car via links, so may be relevant.
- PERFORM ACTIVE TEST USING GTS
- Perform the Active Test according to the display on the GTS.
Powertrain > Engine > Active Test
Tester Display Measurement Item Control Range Restrict Condition Control the Engine Cooling Fan Duty Ratio Control the cooling fan 0 to 100% Perform this test when vehicle is stopped. Powertrain > Engine > Active Test
Tester Display Control the Engine Cooling Fan Duty Ratio OK
Electric cooling fan operates smoothly.
Result
Proceed to OK NG
Result:
NG
GO TO COOLING FAN SYSTEM. Refer to ON-VEHICLE INSPECTION [11/2021 - ]
Result:
OK
See step 2
- Perform the Active Test according to the display on the GTS.
- CHECK REFRIGERANT PRESSURE
- Install a manifold gauge set.
Refer to ON-VEHICLE INSPECTION [11/2021 - ]
- Prepare the vehicle according to the table below.MEASUREMENT CONDITION:
Item Condition Doors Fully open A/C Switch On Recirculation/fresh Control Switch Recirculation Set Temperature MAX COLD Blower Speed HI Air Conditioning Air Inlet Temperature 25 to 35°C (77 to 95°F) - Read the manifold gauge pressure.
Standard Pressure
Low pressure side
150 to 250 kPa (1.5 to 2.5 kgf/cm2 , 22 to 36 psi)
High pressure side
1370 to 1570 kPa (14 to 16 kgf/cm2 , 199 to 228 psi)
Result
Proceed to OK NG
Result:
OK
REPLACE COMPRESSOR WITH MOTOR ASSEMBLY. Refer to REMOVAL [11/2021 - ]
Result:
NG
CHARGE REFRIGERANT. Refer to REPLACEMENT [11/2021 - ]
- Install a manifold gauge set.