DTC P0703-12: Brake Switch "B" Circuit Short to Battery [11/2021 - ]: Procedure

1. Read the Data List displayed on the GTS.

   Powertrain > Engine > Data List 

   Tester Display
   Stop Light SW

   OK

   GTS Display	Measurement Item/Range (Display)	Normal Condition
   Stop Light SW	Stop light switch assembly status: ON or OFF	ON: Brake pedal depressed OFF: Brake pedal released

   Result

   Proceed to
   OK
   NG

Result: 

OK 

CHECK FOR INTERMITTENT PROBLEMS. Refer to  CHECK FOR INTERMITTENT PROBLEMS [11/2021 - ] 

Result: 

NG 

See step  2

1. Check the stop light switch installation.

   Refer to INSTALLATION [11/2021 - ]

   OK

   Stop light switch is installed correctly.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

SECURELY REINSTALL STOP LIGHT SWITCH ASSEMBLY. Refer to  INSTALLATION [11/2021 - ] 

Result: 

OK 

See step  3

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the ECM connector.
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Brake Pedal Operation	Specified Condition
   A19-14 (STP) - Body ground	Released	Below 1.5 V
   	Depressed	7.5 to 14 V

   HINT: 

   If there is a short in the STP terminal circuit, there may be a malfunction in the circuit of a connected ECU.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE ECM. Refer to  REMOVAL [11/2021 - ] 

Result: 

NG 

See step  4

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
   A37-2 (L) or A19-14 (STP) - Other terminals	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE STOP LIGHT SWITCH ASSEMBLY. Refer to  REMOVAL [11/2021 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR