DTC P0571-12: Brake Switch "A" Circuit Short to Battery [08/2020 - ]: Procedure

1. Check the brake pedal height and stop light switch assembly installation.

   Refer to ADJUSTMENT [08/2020 - 08/2021] , or refer to ADJUSTMENT [08/2021 - ]

   OK

   The brake pedal height and stop light switch assembly installation are normal.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

ADJUST BRAKE PEDAL OR STOP LIGHT SWITCH ASSEMBLY. Refer to  ADJUSTMENT [08/2020 - 08/2021]  , or refer to  ADJUSTMENT [08/2021 - ] 

Result: 

OK 

See step  2

1. Make sure that there is no looseness at the locking part and the connecting part of the connector.

   OK

   The connector is securely connected.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component with harness connected (Stop Light Switch Assembly)

2. Disconnect the A40 skid control ECU (brake actuator assembly) connector.
3. Check both the connector case and the terminals for deformation and corrosion.

   OK

   No deformation or corrosion.

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A80-3 (L) - Body ground	Brake pedal released	Below 1.5 V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL [08/2020 - 08/2021]  , or refer to  REMOVAL [08/2021 - 09/2022]  , or refer to  REMOVAL [09/2022 - ] 

Result: 

NG 

See step  3

1. Make sure that there is no looseness at the locking part and the connecting part of the connector.

   OK

   The connector is securely connected.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

2. Disconnect the A40 skid control ECU (brake actuator assembly) connector.
3. Disconnect the A80 stop light switch assembly connector.
4. Check both the connector case and the terminals for deformation and corrosion.

   OK

   No deformation or corrosion.

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A80-3 (L) - Body ground	Always	Below 1.5 V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE STOP LIGHT SWITCH ASSEMBLY. Refer to  REMOVAL [06/2018 - ] 

Result: 

NG 

See step  4

1. Make sure that there is no looseness at the locking part and the connecting part of the connector.

   OK

   The connector is securely connected.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

2. Disconnect the A40 skid control ECU (brake actuator assembly) connector.
3. Disconnect the A80 stop light switch assembly connector.
4. Disconnect the A25 ECM connector. (for 2GR-FKS)
5. Disconnect the A28 ECM connector. (for A25A-FKS)
6. Check both the connector case and the terminals for deformation and corrosion.

   OK

   No deformation or corrosion.

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A80-3 (L) - Body ground	Always	Below 1.5 V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE ECM 

for 2GR-FKS: Refer to REMOVAL [10/2019 - 08/2021] , or refer to REMOVAL [08/2021 - 09/2022] , or refer to REMOVAL [09/2022 - ]

for A25A-FKS: Refer to REMOVAL [08/2020 - 08/2021] , or refer to REMOVAL [08/2021 - 09/2022] , or refer to REMOVAL [09/2022 - ]

Result: 

NG 

See step  5

1. Make sure that there is no looseness at the locking part and the connecting part of the connector.

   OK

   The connector is securely connected.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

2. Disconnect the A40 skid control ECU (brake actuator assembly) connector.
3. Disconnect the A80 stop light switch assembly connector.
4. Disconnect the A25 ECM connector. (for 2GR-FKS)
5. Disconnect the A28 ECM connector. (for A25A-FKS)
6. Disconnect the G25 shift lock control ECU (shift lock control unit assembly) connector.
7. Check both the connector case and the terminals for deformation and corrosion.

   OK

   No deformation or corrosion.

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A80-3 (L) - Body ground	Always	Below 1.5 V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE SHIFT LOCK CONTROL UNIT ASSEMBLY. Refer to  REMOVAL [06/2018 - 09/2022]  , or refer to  REMOVAL [09/2022 - ] 

Result: 

NG 

See step  6

1. Make sure that there is no looseness at the locking part and the connecting part of the connector.

   OK

   The connector is securely connected.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

2. Disconnect the A40 skid control ECU (brake actuator assembly) connector.
3. Disconnect the A80 stop light switch assembly connector.
4. Disconnect the A25 ECM connector. (for 2GR-FKS)
5. Disconnect the A28 ECM connector. (for A25A-FKS)
6. Disconnect the G25 shift lock control ECU (shift lock control unit assembly) connector.
7. Disconnect the N9 certification ECU (smart key ECU assembly) connector.
8. Check both the connector case and the terminals for deformation and corrosion.

   OK

   No deformation or corrosion.

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A80-3 (L) - Body ground	Always	Below 1.5 V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE SMART KEY ECU ASSEMBLY. Refer to  REMOVAL [06/2018 - 08/2021]  , or refer to  REMOVAL [08/2021 - 09/2022]  , or refer to  REMOVAL [09/2022 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR