DTC P0571-62: Brake Switch "A" Signal Compare Failure [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 (STOP LIGHT SWITCH ASSEMBLY - AUXILIARY BATTERY AND BODY GROUND)

Disconnect the stop light switch assembly connector.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*a	Front view of wire harness connector (to Stop Light Switch Assembly)

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

Standard Resistance

Tester Connection	Condition	Specified Condition
A42-2 (GND) - Body ground	Always	Below 1 Ω

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

Standard Voltage

Tester Connection	Condition	Specified Condition
A42-7 (B) - Body ground	Always	11 to 14 V
A42-6 (B) - Body ground	Power switch on (IG)	11 to 14 V
A42-6 (B) - Body ground	Power switch off	Below 1 V

Connect the stop light switch assembly connector.

Result

Proceed to
OK
NG

Result:

REPAIR OR REPLACE HARNESS OR CONNECTOR

Result:

See step 2

INSPECT STOP LIGHT SWITCH ASSEMBLY

Inspect the stop light switch assembly.

Refer to ON-VEHICLE INSPECTION [10/2018 - ]

Result

Proceed to
OK
NG

Result:

REPLACE STOP LIGHT SWITCH ASSEMBLY. Refer to COMPONENTS [10/2018 - ]

Result:

See step 3

CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - STOP LIGHT SWITCH ASSEMBLY)

Disconnect the A46 and F60 hybrid vehicle control ECU connectors.
Disconnect the A42 stop light switch assembly connector.
Disconnect the A37 skid control ECU (brake booster with master cylinder assembly) connector.
Disconnect the N61 certification ECU (smart key ECU assembly) connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
F60-28 (ST1-) - A42-5 (L)	Always	Below 1 Ω
A46-7 (STP) - A42-3 (L)	Always	Below 1 Ω
F60-28 (ST1-) or A42-5 (L) - Body ground	Always	10 kΩ or higher
A46-7 (STP) or A42-3 (L) - Body ground	Always	10 kΩ or higher

Connect the N61 certification ECU (smart key ECU assembly) connector.
Connect the A37 skid control ECU (brake booster with master cylinder assembly) connector.
Connect the A42 stop light switch assembly connector.

Connect the A46 and F60 hybrid vehicle control ECU connectors.

Result

Proceed to
OK
NG

Result:

REPLACE HYBRID VEHICLE CONTROL ECU. Refer to COMPONENTS [10/2018 - ]

Result:

REPAIR OR REPLACE HARNESS OR CONNECTOR