Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001GYT0
Model Year Start: 2020 Model: Corolla Hatchback Prod Date Range: [01/2019 - 11/2022]
Title: K313 (CVT): CONTINUOUSLY VARIABLE TRANSAXLE SYSTEM: U0129; Lost Communication with Brake System Control Module; 2020 - 2023 MY Corolla Corolla Hatchback [01/2019 - 11/2022]

DTC

U0129

Lost Communication with Brake System Control Module

DESCRIPTION

The ECM receives signals sent from the skid control ECU (brake actuator assembly) via the CAN communication system. When DTCs indicating a CAN communication system malfunction are output, repair the CAN communication system before repairing each corresponding ECU or sensor.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

U0129

Lost Communication with Brake System Control Module

No communication between the ECM and skid control ECU (brake actuator assembly) for 2.22 seconds or more (1-trip detection logic)
  • CAN communication system
  • Brake actuator assembly (Skid control ECU)
  • ECM

Does not come on

DTC stored

CONFIRMATION DRIVING PATTERN

HINT:

After repairs have been completed, clear the DTCs and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.

  1. Connect the Techstream to the DLC3.
  2. Turn the ignition switch to ON and turn the Techstream on.
  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
  4. Turn the ignition switch off and wait for 3 minutes or more.
  5. Turn the ignition switch to ON and turn the Techstream on.
  6. Wait for 5 seconds or more with the ignition switch ON.
  7. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
  8. Input the DTC: U0129.
  9. Check the DTC judgment result.

    Techstream Display

    Description

    NORMAL
    • DTC judgment completed
    • System normal

    ABNORMAL
    • DTC judgment completed
    • System abnormal

    INCOMPLETE
    • DTC judgment not completed
    • Perform driving pattern after confirming DTC enabling conditions

    N/A
    • Unable to perform DTC judgment
    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    HINT:

    • If the judgment result shows NORMAL, the system is normal.
    • If the judgment result shows ABNORMAL, the system has a malfunction.
    • If the judgment result shows INCOMPLETE or N/A, perform the Confirmation Driving Pattern and check the DTC judgment result again.

CAUTION / NOTICE / HINT

NOTICE:

  • Perform initialization when parts related to the continuously variable transaxle system are replaced.

    Click here 2020 - 2023 MY Corolla Corolla Hatchback [01/2019 - 11/2022]; K313 (CVT): CONTINUOUSLY VARIABLE TRANSAXLE SYSTEM: INITIALIZATION

  • Check that no DTCs are stored after performing initialization.

    Click here 2020 - 2023 MY Corolla Corolla Hatchback [01/2019 - 11/2022]; K313 (CVT): CONTINUOUSLY VARIABLE TRANSAXLE SYSTEM: DTC CHECK / CLEAR

PROCEDURE

1.

CLEAR DTC AND PERFORM ROAD TEST

(a) Clear the DTCs.

Powertrain > Engine and ECT > Clear DTCs

HINT:

Write down any currently output DTCs before clearing them.

(b) Start the engine and drive the vehicle at a low speed.

NEXT

2.

CHECK DTC OUTPUT (DTC U0129)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

Powertrain > Engine and ECT > Trouble Codes

(e) Read the DTCs using the Techstream.

Result

Proceed to

DTC U0129 is not output

A

DTC U0129 is output

B
A

CHECK FOR INTERMITTENT PROBLEMS

B

GO TO CAN COMMUNICATION SYSTEM 2020 MY Corolla Corolla Hatchback GR Corolla [01/2019 - 03/2019]; NETWORKING: CAN COMMUNICATION SYSTEM (for Gasoline Model): DIAGNOSIS SYSTEM 2020 MY Corolla Corolla Hatchback GR Corolla [03/2019 - 09/2019]; NETWORKING: CAN COMMUNICATION SYSTEM (for Gasoline Model): DIAGNOSIS SYSTEM 2020 MY Corolla Corolla Hatchback GR Corolla [09/2019 - 04/2020]; NETWORKING: CAN COMMUNICATION SYSTEM (for Gasoline Model): DIAGNOSIS SYSTEM 2021 - 2022 MY Corolla Corolla Hatchback GR Corolla [04/2020 - 09/2022]; NETWORKING: CAN COMMUNICATION SYSTEM (for Gasoline Model): DIAGNOSIS SYSTEM 2023 MY Corolla Corolla Hatchback GR Corolla [09/2022 - 11/2022]; NETWORKING: CAN COMMUNICATION SYSTEM (for Gasoline Model except TMC Made): DIAGNOSIS SYSTEM