DTC P0504: Brake Switch "A" / "B" Correlation [04/2013 - 10/2017]: Procedure

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A56-1 (B) - Body ground	Always	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BATTERY) 

Result: 

OK 

See step  2

1. Disconnect the stop light switch assembly connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

2. Turn the engine switch on (IG).
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A56-5 (B) - Body ground	Engine switch on (IG)	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  6

Result: 

OK 

See step  3

1. Disconnect the stop light switch assembly connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A56-3 (GND) - Body ground	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

1. Turn the engine switch on (IG).

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Brake Pedal Depressed
   *b	Brake Pedal Released
   *c	Component with harness connected (ECM)

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

   Standard Voltage

   Tester Connection	Brake Pedal Operation	Specified Condition
   A76-12 (ST1-) - Body ground	Released	7.5 to 14 V
   	Depressed	Below 1.5 V
   A76-13 (STP) - Body ground	Released	Below 1.5 V
   	Depressed	7.5 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE ECM. Refer to  REMOVAL [04/2013 - 10/2017] 

Result: 

NG 

See step  5

1. Disconnect the stop light switch assembly connector.
2. Disconnect the ECM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A56-4 (L) - A76-12 (ST1-)	Always	Below 1 Ω
   A56-2 (L) - A76-13 (STP)	Always	Below 1 Ω
   A56-4 (L) or A76-12 (ST1-) - Body ground	Always	10 kΩ or higher
   A56-2 (L) or A76-13 (STP) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE STOP LIGHT SWITCH ASSEMBLY. Refer to  REMOVAL [04/2013 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - ECM) 

1. Disconnect the stop light switch assembly connector.
2. Disconnect the semiconductor pwr integration ECU connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A56-5 (B) - 2F-4	Always	Below 1 Ω
   A56-5 (B) or 2F-4 - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE SEMICONDUCTOR POWER INTEGRATION ECU. Refer to  REMOVAL [04/2013 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR