VEHICLE STABILITY CONTROL SYSTEM(for Hydraulic Brake Booster), Diagnostic DTC:C1439, C1445

DTC Code DTC Name
C1439 Steering Angle Sensor Initialization Incomplete
C1445 Vehicle Driven with Steering Angle Sensor not Initialized

DESCRIPTION

The skid control ECU acquires steering angle sensor zero point every time the ignition switch is turned to ON and the vehicle is driven at 40 km/h (25 mph) or more for approximately 10 seconds. The ECU also stores the previous zero point.

The steering angle sensor zero point malfunction warning is canceled by turning the ignition switch off.

DTC Code DTC Detection Condition Trouble Area
C1439 After the steering angle sensor zero point calibration is cleared due to, for example, fluctuations in the power source, the steering angle zero point calibration cannot be obtained for 60 seconds of continuous driving.

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

  • Yaw rate and acceleration sensor (Airbag sensor assembly)

  • Skid control ECU (Master cylinder solenoid)
C1445 Steering angle sensor zero point calibration cannot be obtained when the vehicle is driven without a record of steering angle sensor zero point calibration at a speed of 36 km/h (22 mph) or more for 30 seconds or more without the brake pedal being depressed.

CAUTION / NOTICE / HINT

Note


  • Before proceeding with the inspection, explain to the customer that the output DTC is related to temporary loss of the steering angle zero point calibration, such as when the power voltage drops when the battery is removed, and confirm that this condition occurred.

  • When replacing the skid control ECU (master cylinder solenoid), perform calibration Click here.

Tech Tips


  • When DTC U0073, U0123, U0124 and/or U0126 is output together with DTC C1439 and/or C1445, inspect and repair the trouble areas indicated by DTC U0073, U0123, U0124 and/or U0126 first Click here.

  • When the speed sensor or the yaw rate and acceleration sensor (airbag sensor assembly) has trouble, DTCs for the steering angle sensor (spiral with sensor cable sub-assembly) may be stored even when the steering angle sensor (spiral with sensor cable sub-assembly) is normal. When DTCs for the speed sensor or yaw rate and acceleration sensor (airbag sensor assembly) are output together with other DTCs for the steering angle sensor (spiral with sensor cable sub-assembly), inspect and repair the speed sensor and yaw rate and acceleration sensor (airbag sensor assembly) first, and then inspect and repair the steering angle sensor.

PROCEDURE


  1. CHECK DTC


    1. Clear the DTCs Click here.

    2. Turn the ignition switch off.

    3. Turn the ignition switch to ON again and check that no CAN communication system DTC is output.

    4. Drive the vehicle at a speed of 40 km/h (25 mph) and turn the steering wheel to the right and left, and then check that no speed sensor and yaw rate and acceleration sensor (airbag sensor assembly) DTCs are output Click here.

      Result
      Result Proceed to
      DTC is output C1439 and/or C1445 A
      Relating to CAN communication system (w/ Central Gateway ECU) B
      Relating to CAN communication system (w/o Central Gateway ECU) C
      Relating to speed sensor or yaw rate and acceleration sensor (airbag sensor assembly) D
      DTC is not output E

      Tech Tips


      • If there is a malfunction in the speed sensor or the yaw rate and acceleration sensor (airbag sensor assembly), an abnormal value may be output although the steering angle sensor is normal.

      • If the speed sensor and the yaw rate and acceleration sensor (airbag sensor assembly) DTCs are output simultaneously, repair the sensors and inspect the steering angle sensor.

      • If DTC C1439 and/or C1445 is not output again, the DTC may have been stored due to a temporary loss of the steering angle zero point calibration, such as when the power voltage drops.


    B

    GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) Click here

    C

    GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) Click here

    D

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Click here

    E

    USE SIMULATION METHOD TO CHECK Click here

    A

  2. PERFORM STEERING ANGLE SENSOR ZERO POINT CALIBRATION


    1. Drive the vehicle straight ahead at 40 km/h (25 mph) or more for at least 10 seconds.

    2. Check that the centered position of the steering wheel is correctly set while driving straight ahead.

      Tech Tips

      If the front wheel alignment and steering position are adjusted as a result of an abnormal centered position of the steering wheel, acquire the yaw rate and acceleration sensor zero point again after the adjustments are completed.

      OK
      The centered position of the steering wheel is correctly set.

    NG

    ADJUST FRONT WHEEL ALIGNMENT OR STEERING POSITION Click here

    OK

  3. RECONFIRM DTC


    1. Clear the DTC Click here.

    2. Turn the ignition switch off.

    3. Start the engine.

    4. Drive the vehicle at a speed of 40 km/h (25 mph) or more and turn the steering wheel to the right and left.

    5. Check if the same DTC is output Click here.

      Result
      Result Proceed to
      DTCs C1439 and C1445 are not output A
      Yaw rate and acceleration sensor (airbag sensor assembly) and/or steering angle sensor (spiral with sensor cable sub-assembly) DTC is output B

      Tech Tips

      If the same DTC C1439 and/or C1445 is not output again, the DTC may have been stored due to a temporary loss of the steering angle zero point calibration, such as when the power voltage drops.


    A

    END

    B

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Click here