PRE-CRASH SAFETY SYSTEM, Diagnostic DTC:U0100, U0125, U0126, U0129

DTC Code DTC Name
U0100 Lost Communication With ECM/PCM "A"
U0125 Lost Communication with Yaw Rate Sensor Module
U0126 Lost Communication with Steering Angle Sensor Module
U0129 Lost Communication with Brake System Control Module

DESCRIPTION

The driving support ECU assembly uses the millimeter wave radar sensor assembly to detect objects in front of the vehicle. Based on signals from the millimeter wave radar sensor assembly, the driving support ECU assembly sends pre-crash safety system control operation signals. These DTCs are stored when a communication malfunction occurs between ECUs that perform pre-crash safety system control.

DTC No. Detection Item DTC Detection Condition Trouble Area
U0100 Lost Communication With ECM/PCM "A" When the vehicle is being driven at a speed of 5 km/h (4 mph) or more, a communication error between the ECM and the driving support ECU assembly is detected for approximately 5 seconds.

  • CAN communication system

  • ECM

  • Driving support ECU assembly

  • Harness or connector
U0125 Lost Communication with Yaw Rate Sensor Module When the ignition switch is ON, a communication error between the yaw rate sensor (airbag sensor assembly) and the driving support ECU is detected for approximately 1 second.

  • CAN communication system

  • Yaw rate sensor (airbag sensor assembly)

  • Driving support ECU assembly

  • Harness or connector
U0126 Lost Communication with Steering Angle Sensor Module When the ignition switch is ON, a communication error between the steering angle sensor (spiral with sensor cable sub-assembly) and the driving support ECU assembly is detected for approximately 4 seconds.

  • CAN communication system

  • Steering angle sensor (spiral with sensor cable sub-assembly)

  • Driving support ECU assembly

  • Harness or connector
U0129 Lost Communication with Brake System Control Module

  • for 2TR-FE:

    When the ignition switch is ON, a communication error between the skid control ECU (brake actuator assembly) and the driving support ECU assembly is detected for approximately 3 seconds.

  • except 2TR-FE:

    When the ignition switch is ON, a communication error between the skid control ECU (master cylinder solenoid) and the driving support ECU assembly is detected for approximately 3 seconds.

  • CAN communication system

  • Skid control ECU assembly (brake actuator assembly) (for 2TR-FE)

  • Skid control ECU assembly (master cylinder solenoid) (except 2TR-FE)

  • Driving support ECU assembly

  • Harness or connector

PROCEDURE


  1. CHECK FOR DTCs (PRE-CRASH SAFETY SYSTEM)


    1. Clear the DTCs.

      Click here

    2. Make sure that the DTC detection conditions are met.

      Tech Tips

      If the detection conditions are not met, the system cannot detect the malfunction.

    3. Check for DTCs.

      Click here

      Result
      Result Proceed to
      DTC U0100, U0125, U0126 and U0129 are not output A
      DTC U0100, U0125, U0126 or U0129 is output B

    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    GO TO CAN COMMUNICATION SYSTEM Click here