Electric Parking Brake does not Operate [11/2022 - ]: Procedure

1. Check if CAN communication system DTCs are output.

   Chassis > Brake/EPB > Trouble Codes 

   Result

   Result	Proceed to
   DTCs are not output	A
   DTCs are output	B

Result: 

B 

GO TO CAN COMMUNICATION SYSTEM 

Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2022 - 11/2023] , or refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2023 - 12/2024] , or refer to HOW TO PROCEED WITH TROUBLESHOOTING [12/2024 - ]

Result: 

A 

See step  2

1. With the wheels not contacting the ground, check the condition of the rear wheels when the electric parking brake is operating and not operating.

   Refer to ON-VEHICLE INSPECTION [09/2021 - ]

   Result

   Result	Proceed to
   Lock and release operation is normal and parking brake indicator light turns off or blinks (red)	A
   Lock and release operation is malfunctioning and parking brake indicator light illuminates (red) or turns off according to switch operation	B
   Lock and release operation is malfunctioning and parking brake indicator light turns off or blinks (red)	C

Result: 

B 

INSPECT REAR BRAKE 

Result: 

C 

See step  4

Result: 

A 

See step  3

1. Perform the Active Test of the combination meter assembly using the GTS.

   Body Electrical > Combination Meter > Active Test 

   Tester Display
   Park Warning

2. Check the combination meter assembly.

   OK

   Parking brake indicator light (red) turns on or off in accordance with GTS operation.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) 

Refer to REMOVAL [11/2022 - ]

Result: 

NG 

GO TO METER / GAUGE SYSTEM 

Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2022 - ]

1. Turn the ignition switch off.
2. Disconnect the A151 skid control ECU (brake actuator assembly) connector.
3. Measure the voltage according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Skid Control ECU (Brake Actuator Assembly))

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A151-30 (+BS) - Body ground	Always	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  5

1. Turn the ignition switch off.
2. Disconnect the A151 skid control ECU (brake actuator assembly) connector.
3. Measure the voltage according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Skid Control ECU (Brake Actuator Assembly))

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A151-36 (IGR) - Body ground	Ignition switch ON	10.5 to 16 V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) 

Refer to REMOVAL [11/2022 - ]

Result: 

NG 

See step  6

1. Turn the ignition switch off.
2. Disconnect the A151 skid control ECU (brake actuator assembly) connector.
3. Disconnect the I230 engine stop and start ECU connector.
4. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A151-36 (IGR) - I230-23 (IG31)	Always	Below 1 Ω
   A151-36 (IGR) or I230-23 (IG31) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

GO TO STOP AND START SYSTEM 

Refer to Backup Boost Converter Circuit [11/2022 - ]

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR