DTC P0571-62: Brake Switch "A" Signal Compare Failure [08/2020 - ]: Procedure
WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 2024 Lexus ES 350, 2024 Lexus ES 250, 2023 Lexus ES 350, 2023 Lexus ES 250, and 2022 Lexus ES 350. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BATTERY AND BODY GROUND)
- Disconnect the A80 stop light switch assembly connector.
*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 A80-2 (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 A80-7 (B) - Body ground Always 11 to 14 V A80-6 (B) - Body ground Engine switch on (IG) 11 to 14 V A80-6 (B) - Body ground Engine switch off Below 1 V - Connect the A80 stop light switch assembly connector.
Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 2
- Disconnect the A80 stop light switch assembly connector.
- INSPECT STOP LIGHT SWITCH ASSEMBLY
- Inspect the stop light switch assembly.
Refer to ON-VEHICLE INSPECTION [08/2020 - ]
Result
Proceed to OK NG
Result:
NG
REPLACE STOP LIGHT SWITCH ASSEMBLY. Refer to COMPONENTS [06/2018 - ]
Result:
OK
See step 3
- Inspect the stop light switch assembly.
- CHECK HARNESS AND CONNECTOR (ECM - STOP LIGHT SWITCH ASSEMBLY)
- Disconnect the A25 ECM connector.*1
- Disconnect the A28 ECM connector.*2
- Disconnect the A80 stop light switch assembly connector.
- Disconnect the A40 skid control ECU (brake actuator assembly) connector.
- Disconnect the N9 certification ECU (smart key ECU assembly) connector.
- Disconnect the G25 shift lock control ECU (shift lock control unit assembly) connector.
- *1: for 2GR-FKS
- *2: for A25A-FKS
- Measure the resistance according to the value(s) in the table below.
Standard Resistance (for 2GR-FKS)
Tester Connection Condition Specified Condition A25-42 (ST1-) - A80-5 (L) Always Below 1 Ω A25-27 (STP) - A80-3 (L) Always Below 1 Ω A25-42 (ST1-) or A80-5 (L) - Body ground Always 10 kΩ or higher A25-27 (STP) or A80-3 (L) - Body ground Always 10 kΩ or higher Standard Resistance (for A25A-FKS)
Tester Connection Condition Specified Condition A28-22 (ST1-) - A80-5 (L) Always Below 1 Ω A28-21 (STP) - A80-3 (L) Always Below 1 Ω A28-22 (ST1-) or A80-5 (L) - Body ground Always 10 kΩ or higher A28-21 (STP) or A80-3 (L) - Body ground Always 10 kΩ or higher - Connect the G25 shift lock control ECU (shift lock control unit assembly) connector.
- Connect the N9 certification ECU (smart key ECU assembly) connector.
- Connect the A40 skid control ECU (brake actuator assembly) connector.
- Connect the A80 stop light switch assembly connector.
- Connect the A25 ECM connector.*1
- Connect the A28 ECM connector.*2
- *1: for 2GR-FKS
- *2: for A25A-FKS
Result
Proceed to OK NG
Result:
OK
REPLACE ECM
For 2GR-FKS: Refer to COMPONENTS [06/2018 - ]
For A25A-FKS: Refer to COMPONENTS [08/2020 - 08/2021] , or refer to COMPONENTS [08/2021 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR