DTC P0504: Brake Switch "A" / "B" Correlation [08/2013 - ]: Procedure

1. Disconnect the stop light switch assembly connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A22-2 - Body ground	Always	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

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

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

OK: Go to next step 

1. Disconnect the stop light switch assembly connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   A22-4 - Body ground	Engine switch on (IG)	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

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

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - IG2 RELAY) 

OK: Go to next step 

1. Inspect the stop light switch assembly. Refer to INSPECTION [08/2013 - ] .

NG → See step   5 

OK: Go to next step 

1. Disconnect the ECM connectors.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Voltage

   Tester Connection	Brake Pedal Operation	Specified Condition
   A5-8 (ST1-) - Body ground	Released	7.5 to 14 V
   	Depressed	Below 1.5 V
   A6-4 (STP) - Body ground	Released	Below 1.5 V
   	Depressed	7.5 to 14 V

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

OK → See step   6