DTC C1428: Motor Circuit [10/2018 - ]: Procedure
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Lexus UX 250h, 2023 Lexus UX 250h, 2022 Lexus UX 250h, 2021 Lexus UX 250h, and 2020 Lexus UX 250h. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - BRAKE ACTUATOR ASSEMBLY)
- Make sure that there is no looseness at the locking part and the connecting part of the connectors.
OK
The connector is securely connected.
- Disconnect the A37 skid control ECU (brake booster with master cylinder assembly) connector.
- Disconnect the A48 brake actuator assembly connector.
- Check both the connector case and the terminals for deformation and corrosion.
OK
No deformation or corrosion.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A37-40 (+BM) - A48-10 (+BM) Always Below 1 Ω A37-40 (+BM) or A48-10 (+BM) - Body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 2
- Make sure that there is no looseness at the locking part and the connecting part of the connectors.
- CHECK HARNESS AND CONNECTOR (GND TERMINAL)
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A48-1 (MGND) - Body ground Always Below 1 Ω *a Front view of wire harness connector
(to Brake Actuator Assembly)Result
Proceed to OK NG
Result:
OK
REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to REMOVAL [10/2018 - 07/2022] , or refer to REMOVAL [07/2022 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)
- Measure the resistance according to the value(s) in the table below.