Last Modified: 12-11-2024 6.11:8.1.0 Doc ID: RM100000002OT6B
Model Year Start: 2025 Model: GR Corolla Prod Date Range: [09/2024 -           ]
Title: UC80F (AUTOMATIC TRANSMISSION / TRANSAXLE): AUTOMATIC TRANSAXLE SYSTEM: U012987; Lost Communication with Brake System Control Module Missing Message; 2025 MY Corolla Corolla Hatchback GR Corolla [09/2024 -        ]

DTC

U012987

Lost Communication with Brake System Control Module Missing Message

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

Note

U012987

Lost Communication with Brake System Control Module Missing Message

No communication between the ECM and skid control ECU (brake actuator assembly) for 2.2 seconds or more (1-trip detection logic)
  • CAN communication system
  • Brake actuator assembly (Skid control ECU)
  • ECM

Does not come on

SAE Code:

U0129

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. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
  2. Turn the ignition switch off and wait for 2 minutes or more.
  3. Turn the ignition switch to ON and turn the GTS on.
  4. Wait for 3 seconds or more with the ignition switch ON.
  5. Enter the following menus: Powertrain / Transmission / Utility / All Readiness.
  6. Input the DTC: U012987.
  7. Check the DTC judgment result.

    GTS 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 registration and/or initialization when parts related to the automatic transaxle are replaced.

Click here 2025 MY Corolla Corolla Hatchback GR Corolla [09/2024 -        ]; UC80F (AUTOMATIC TRANSMISSION / TRANSAXLE): AUTOMATIC TRANSAXLE SYSTEM: PRECAUTION

PROCEDURE

1.

CLEAR DTC

(a) Clear the DTCs.

Powertrain > Transmission > Clear DTCs

HINT:

Write down the currently output DTCs before clearing them.

NEXT

2.

CHECK DTC OUTPUT (DTC U012987)

Pre-procedure1

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

Procedure1

(b) Read the DTCs using the GTS.

Powertrain > Transmission > Trouble Codes

Result

Proceed to

U012987 is not output

A

U012987 is output

B

Post-procedure1

(c) None

A

CHECK FOR INTERMITTENT PROBLEMS

B

GO TO CAN COMMUNICATION SYSTEM