Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000002D0FT
Model Year Start: 2024 Model: GR Corolla Prod Date Range: [08/2023 -           ]
Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for Gasoline Model with Electric Parking Brake System): C137BA3; Brake System Control Module "A" System Voltage System Voltage High; 2024 - 2025 MY Corolla Corolla Hatchback GR Corolla [08/2023 -        ]

DTC

C137BA3

Brake System Control Module "A" System Voltage System Voltage High

DESCRIPTION

If a malfunction is detected in the power supply circuit, the skid control ECU (brake actuator assembly) stores this DTC and the fail-safe function prohibits ABS operation.

This DTC is stored when the +BS terminal voltage deviates due to a malfunction in a power supply or charging system circuit such as the battery or alternator circuit, etc.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Note

C137BA3

Brake System Control Module "A" System Voltage System Voltage High

+BS terminal voltage is more than 16.5 V for 1 second or more.
  • Wire harness or connector
  • Skid control ECU (brake actuator assembly)

Does not come on

-

WIRING DIAGRAM

Refer to DTC C117A49

Click here 2024 - 2025 MY Corolla Corolla Hatchback GR Corolla [08/2023 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for Gasoline Model with Electric Parking Brake System): C117A49,C137BA2; Brake System Control Module "A" System Voltage Line Internal Electronic Failure

CAUTION / NOTICE / HINT

NOTICE:

  • Inspect the fuses for circuits related to this system before performing the following procedure.
  • Before performing troubleshooting, make sure to confirm that the battery voltage is normal.

    Click here 2019 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2018 -        ]; INTRODUCTION: HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS: HOW TO PROCEED WITH TROUBLESHOOTING

PROCEDURE

1.

CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)

(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

*a

Front view of wire harness connector

(to Skid Control ECU (Brake Actuator Assembly))

(b) Disconnect the A51 skid control ECU (brake actuator assembly) connector.

(c) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A51-30 (+BS) - Body ground

Always

11 to 14 V
OK

REPLACE BRAKE ACTUATOR ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR