DTC P0571-62: Brake Switch "A" Signal Compare Failure [08/2020 - ]: Procedure

1. Disconnect the A80 stop light switch assembly connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

2. 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

3. 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

4. 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

1. 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

1. Disconnect the A25 ECM connector.*1
2. Disconnect the A28 ECM connector.*2
3. Disconnect the A80 stop light switch assembly connector.
4. Disconnect the A40 skid control ECU (brake actuator assembly) connector.
5. Disconnect the N9 certification ECU (smart key ECU assembly) connector.
6. Disconnect the G25 shift lock control ECU (shift lock control unit assembly) connector.
   1. *1: for 2GR-FKS
   2. *2: for A25A-FKS
7. 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

8. Connect the G25 shift lock control ECU (shift lock control unit assembly) connector.
9. Connect the N9 certification ECU (smart key ECU assembly) connector.
10. Connect the A40 skid control ECU (brake actuator assembly) connector.
11. Connect the A80 stop light switch assembly connector.
12. Connect the A25 ECM connector.*1
13. Connect the A28 ECM connector.*2
    1. *1: for 2GR-FKS
    2. *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