DTC P0571-13: Brake Switch "A" Circuit Open [09/2018 - 10/2023]: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Select the Data List using the Techstream.

   Refer to DATA LIST / ACTIVE TEST [09/2018 - 10/2023]

   Chassis > Brake > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   Stop Light SW	Stop light switch assembly	OFF / ON	OFF: Brake pedal released ON: Brake pedal depressed	-

   Chassis > Brake > Data List 

   Tester Display
   Stop Light SW

4. Check that the stop light switch display observed on the Techstream changes according to brake pedal operation.

   OK

   The Techstream displays OFF / ON according to brake pedal operation.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  3

Result: 

OK 

See step  2

1. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [09/2018 - 10/2023]

   Chassis > Brake > Clear DTCs 

2. Turn the engine switch off.
3. Start the engine.
4. Depress the brake pedal several times to test the stop light circuit.
5. Check if the same DTC is output.

   Refer to DTC CHECK / CLEAR [09/2018 - 10/2023]

   Chassis > Brake > Trouble Codes 

   Result

   Result	Proceed to
   DTC P0571-13 is not output.	A
   DTC P0571-13 is output.	B

Result: 

A 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [09/2018 - 10/2020]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2020 - 11/2021]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [11/2021 - 10/2022]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2022 - 10/2023] 

Result: 

B 

REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL [09/2018 - 10/2020]  , or refer to  REMOVAL [10/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023] 

1. Turn the engine switch off.
2. Make sure that there is no looseness at the locking part and the connecting part of the connectors.
3. Disconnect the A9 skid control ECU (brake actuator assembly) connector.
4. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   A9-35 (STP) - Body ground	Stop light switch on (Brake pedal depressed)	8 to 14 V
   A9-35 (STP) - Body ground	Stop light switch off (Brake pedal released)	Below 1.5 V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL [09/2018 - 10/2020]  , or refer to  REMOVAL [10/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)