DTC P0504: Brake Switch "A" / "B" Correlation [12/2012 - 10/2015]: 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
   A5-2 - Body ground	Always	11 to 14 V

Result: 

NG 

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

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 ignition switch to ON.
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   A5-4 - Body ground	Ignition switch ON	11 to 14 V

Result: 

NG 

See step  5

Result: 

OK 

See step  3

1. Inspect the stop light switch assembly.

   Refer to INSPECTION [12/2012 - 10/2015]

Result: 

NG 

REPLACE STOP LIGHT SWITCH ASSEMBLY:  REMOVAL [12/2012 - ] 

Result: 

OK 

See step  4

1. Disconnect the ECM connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Brake Pedal Depressed	*b	Brake Pedal Released
   *c	Front view of wire harness connector (to ECM)	-	-

2. Turn the ignition switch to ON.
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A62-24 (ST1-) - Body ground	Brake pedal released	7.5 to 14 V
   	Brake pedal depressed	Below 1.5 V
   A62-11 (STP) - Body ground	Brake pedal released	Below 1.5 V
   	Brake pedal depressed	7.5 to 14 V

Result: 

OK 

REPLACE ECM:  REMOVAL [12/2012 - ] 

Result: 

NG 

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

1. Remove the IG2 relay from the engine room relay block and junction block assembly.
2. Disconnect the stop light switch assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   IG2 relay terminal 5 - A5-4	Always	Below 1 Ω
   IG2 relay terminal 5 or A5-4 - Body ground	Always	10 kΩ or higher

Result: 

OK 

GO TO ECM POWER SOURCE CIRCUIT:  ECM Power Source Circuit [12/2012 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR