Last Modified: 07-31-2024 6.11:8.1.0 Doc ID: RM10000000260S7
Model Year Start: 2023 Model: GR Corolla Prod Date Range: [09/2022 -           ]
Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for Gasoline Model without Electric Parking Brake System TMC Made): C137BA3; Brake System Control Module "A" System Voltage System Voltage High; 2023 - 2025 MY Corolla Corolla Hatchback GR Corolla [09/2022 -        ]

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 operation of ABS, brake assist, etc.

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

The DTC is cleared when the +BS terminal voltage returns to normal.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

C137BA3

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

The +BS terminal voltage is 17.4 V or more for 0.8 seconds or more.
  • Wire harness and connector
  • Skid control ECU (Brake actuator assembly)

WIRING DIAGRAM

Refer to DTC C137BA2.

Click here 2023 - 2025 MY Corolla Corolla Hatchback GR Corolla [09/2022 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for Gasoline Model without Electric Parking Brake System TMC Made): C137BA2; Brake System Control Module "A" System Voltage System Voltage Low+

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 (+BS TERMINAL)

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

OK:

The connector is securely connected.

*a

Front view of wire harness connector

(to Skid Control ECU (Brake Actuator Assembly))

(b) Disconnect the A140 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

A140-14 (+BS) - Body ground

Always

11 to 14 V

A140-14 (+BS) - A140-1 (GND1)

Always

11 to 14 V
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

2.

CLEAR DTC

(a) Reconnect the A140 skid control ECU (brake actuator assembly) connector.

(b) Clear the DTCs.

Chassis > Brake/EPB > Clear DTCs

(c) Turn the ignition switch off.

NEXT

3.

RECONFIRM DTC

(a) Based on the Freeze Frame Data and interview with the customer, attempt to reproduce the conditions when the malfunction occurred.

(b) Check if the same DTC is output.

Chassis > Brake/EPB > Trouble Codes

Result

Proceed to

DTC C137BA3 is not output.

A

DTC C137BA3 is output.

B
A

USE SIMULATION METHOD TO CHECK

B

REPLACE BRAKE ACTUATOR ASSEMBLY 2023 MY Corolla Corolla Hatchback GR Corolla [09/2022 - 11/2022]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: BRAKE ACTUATOR (for Gasoline Model): REMOVAL 2023 - 2025 MY Corolla Corolla Hatchback GR Corolla [11/2022 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: BRAKE ACTUATOR (for Gasoline Model): REMOVAL