DTC P0504: Brake Switch "A" / "B" Correlation: Procedure

1. Disconnect the stop light switch assembly connector.
   Fig 1: Identifying A19 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	Switch Condition	Specified Condition
   A19-2 - Body ground	Always	11 to 14 V
   A19-4 - Body ground	Ignition switch ON	11 to 14 V

3. Reconnect the stop light switch assembly connector.

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

OK: Go to next step 

1. Inspect the stop light switch assembly, refer to INSPECTION .

NG → See step   4 

OK: Go to next step 

1. Turn the ignition switch to ON.
   Fig 2: Identifying Brake Pedal Depressed & Released Position

   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
   D60-15 (ST1-) - Body ground	Brake pedal released	7.5 to 14 V
   	Brake pedal depressed	Below 1.5 V

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   D60-20 (STP) - Body ground	Brake pedal released	Below 1.5 V
   	Brake pedal depressed	7.5 to 14 V

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

OK → See step   5