DTC P0571-62: Brake Switch "A" Signal Compare Failure [09/2023 - ]: Procedure

1. Read the Data List according to the display on the GTS.

   Body Electrical > Power Source Control > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   Stop Light Switch	State of brake pedal	OFF or ON	OFF: Brake pedal released	Use this item to determine if the stop light switch assembly is malfunctioning. The hybrid control system cannot be started when this item is OFF. If the stop light switch assembly is malfunctioning, the hybrid control system can be started by pressing and holding the power switch for a certain period of time.

   Body Electrical > Power Source Control > Data List 

   Tester Display
   Stop Light Switch

   OK

   The GTS display changes correctly in response to the brake pedal operation.

   Result

   Result	Proceed to
   The value of Stop Light Switch is OFF	A
   The value of Stop Light Switch is not OFF	B

Result: 

B 

See step  3

Result: 

A 

See step  2

1. Read the Data List according to the display on the GTS.

   Body Electrical > Power Source Control > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   Stop Light Switch	State of brake pedal	OFF or ON	ON: Brake pedal depressed	Use this item to determine if the stop light switch assembly is malfunctioning. The hybrid control system cannot be started when this item is OFF. If the stop light switch assembly is malfunctioning, the hybrid control system can be started by pressing and holding the power switch for a certain period of time.

   Body Electrical > Power Source Control > Data List 

   Tester Display
   Stop Light Switch

   OK

   The GTS display changes correctly in response to the brake pedal operation.

   Result

   Result	Proceed to
   The value of Stop Light Switch is ON	A
   The value of Stop Light Switch is not ON	B

Result: 

A 

GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING). Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [09/2023 - 12/2023]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2023 - ] 

Result: 

B 

See step  3

Pre-procedure1

• Disconnect the B7 certification ECU (smart key ECU assembly) connector.
• Disconnect the B33 stop light switch assembly connector.
• Disconnect the B34 No. 2 skid control ECU (brake actuator assembly) connector.
• Disconnect the B35 No. 1 skid control ECU (brake booster with master cylinder assembly) connector.
• Disconnect the B21 hybrid vehicle control ECU assembly connector.
• Disconnect the B60 semiconductor power integration ECU connector.
• Disconnect the D25 transmission floor shift assembly connector.

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

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  B7-21 (STP1) - B33-2 (L)	Always	Below 1 Ω	Ω

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Connect the B7 certification ECU (smart key ECU assembly) connector.
• Connect the B33 stop light switch assembly connector.

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component with harness connected (Certification ECU (Smart Key ECU Assembly))

   Tester Connection	Condition	Specified Condition	Result
   B7-21 (STP1) - Body ground	Brake pedal released	1 V or less	V
   B7-21 (STP1) - Body ground	Brake pedal depressed	9 V or higher	V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [09/2023 - 12/2023]  , or refer to  REMOVAL [12/2023 - ] 

Result: 

NG 

REPLACE STOP LIGHT SWITCH ASSEMBLY. Refer to  REMOVAL [09/2023 - ]