Toyota Avalon Service & Repair Manual: EPB Switch Malfunction (C13B4)

DESCRIPTION

When the electric parking brake switch is pulled, a lock request signal is sent from the skid control ECU (brake actuator assembly) to the parking brake actuator assembly. When the electric parking brake switch is pushed, a release request signal is sent from the skid control ECU (brake actuator assembly) to the parking brake actuator assembly.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Memory

Note

C13B4

EPB Switch Malfunction

  • Parking brake switch open or short circuit is detected for 1 second or more
  • Parking brake switch stuck malfunction
  • Electric parking brake switch (electric parking brake switch assembly)
  • Wire harness or connector
  • Skid control ECU (brake actuator assembly)

DTC stored

An electric parking brake system malfunction is displayed on the multi-information display.

DTC Detection Conditions
 

Vehicle Condition

Pattern 1

Pattern 2

Diagnosis Condition

-

-

-

Malfunction Status

Parking brake switch open or short circuit is detected for 1 second or more

-

Parking brake switch stuck malfunction

-

Detection Time

1 second or more

-

Number of Trips

1 trip

1 trip

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • The electric parking brake may still operate up to 20 seconds after the engine switch is turned off. Before disconnecting connectors or fuses, turn the engine switch off and wait 20 seconds or more.
  • When replacing the skid control ECU (brake actuator assembly), operate the electric parking brake switch (electric parking brake switch assembly) as the parking brake indicator light (red) blinks when the engine switch is first turned on (IG).

PROCEDURE

1.

INSPECT ELECTRIC PARKING BRAKE SWITCH (ELECTRIC PARKING BRAKE SWITCH ASSEMBLY)

(a) Remove the electric parking brake switch (electric parking brake switch assembly).

Click here

(b) Inspect the electric parking brake switch (electric parking brake switch assembly).

Click here

NG

REPLACE ELECTRIC PARKING BRAKE SWITCH (ELECTRIC PARKING BRAKE SWITCH ASSEMBLY)

OK

2.

CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - ELECTRIC PARKING BRAKE SWITCH (ELECTRIC PARKING BRAKE SWITCH ASSEMBLY))

(a) Disconnect the G24 electric parking brake switch (electric parking brake switch assembly) connector.

(b) Disconnect the A28 skid control ECU (brake actuator assembly) connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A28-31 (SWI1) - G24-9 (SWI1)

Always

Below 1 Ω

A28-32 (SWO1) - G24-10 (SWO1)

Always

Below 1 Ω

A28-15 (SWI2) - G24-1 (SWI2)

Always

Below 1 Ω

A28-16 (SWO2) - G24-2 (SWO2)

Always

Below 1 Ω

A28-31 (SWI1) or G24-9 (SWI1) - Body ground

Always

10 kΩ or higher

A28-32 (SWO1) or G24-10 (SWO1) - Body ground

Always

10 kΩ or higher

A28-15 (SWI2) or G24-1 (SWI2) - Body ground

Always

10 kΩ or higher

A28-16 (SWO2) or G24-2 (SWO2) - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.

CHECK DTC

(a) Clear the DTCs.

Chassis > ABS/VSC/TRAC/EPB > Clear DTCs

(b) Turn the engine switch off.

(c) Turn the engine switch on (IG).

(d) Check for DTCs.

Chassis > ABS/VSC/TRAC/EPB > Trouble Codes

Result

Proceed to

DTCs are output

A

DTCs are not output

B

A

REPLACE SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY)

B

USE SIMULATION METHOD TO CHECK

    EPB High Temperature (C13AA)

    Data List / Active Test

    See More:

    Toyota Avalon Service & Repair Manual > Brake System(for Hv Model): Problem Symptoms Table
    PROBLEM SYMPTOMS TABLE HINT: Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected ...

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