DTC P0703-12: Brake Switch "B" Circuit Short to Battery [10/2022 - ]: 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 [10/2022 - ] 

Result: 

NG 

See step  2

1. Check the stop light switch installation.

   HINT: 

   Refer to INSTALLATION [10/2022 - ]

   OK

   Stop light switch is installed correctly.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

SECURELY REINSTALL STOP LIGHT SWITCH ASSEMBLY. Refer to  INSTALLATION [10/2022 - ] 

Result: 

OK 

See step  3

Pre-procedure1

• Disconnect the ECM connector.

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

  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

  *a	Brake pedal depressed	*b	Brake pedal released
  *c	Front view of wire harness connector (to ECM)	-	-

  Standard Voltage

  Tester Connection	Brake Pedal Operation	Specified Condition	Result
  A16-14 (STP) - Body ground	Released	Below 1.5 V	V
  A16-14 (STP) - Body ground	Depressed	7.5 to 14 V	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

Post-procedure1

• None.

Result: 

OK 

REPLACE ECM. Refer to  REMOVAL [10/2022 - ] 

Result: 

NG 

See step  4

Pre-procedure1

• Disconnect the stop light switch assembly connector.
• Disconnect the ECM connector.

• Measure the resistance according to the value(s) in the table below.

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  A32-2 (L) or A16-14 (STP) - Other terminals	Always	10 kΩ or higher	kΩ

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None.

Result: 

OK 

REPLACE STOP LIGHT SWITCH ASSEMBLY. Refer to  REMOVAL [10/2022 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR