ELECTRONICALLY CONTROLLED BRAKE SYSTEM, 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 assembly acquires the steering angle sensor zero point every time the power switch is turned on (IG) and the vehicle is driven at 35 km/h (22 mph) or more for approximately 5 seconds. The ECU also stores previous zero points.

Warning of the steering angle sensor zero point malfunction will be canceled by turning the power switch off.

DTC Code INF Code DTC Detection Condition Trouble Area
C1439 352 After the steering sensor zero point calibration is cleared due to, for example, fluctuations in the power source, the steering sensor zero point calibration cannot be obtained for 60 seconds of continuous driving.

  • Steering sensor

  • Yaw rate sensor

  • Skid control ECU assembly
C1445 353 Steering sensor zero point calibration cannot be obtained when the vehicle is driven without a record of steering 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.

  • Steering sensor

  • Yaw rate sensor

  • Skid control ECU assembly

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 calibration, such as when the power source voltage drops when the battery is removed, and confirm that this condition occurred.

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 sensor has trouble, DTCs for the steering sensor may be output even when the steering sensor is normal. When DTCs for the speed sensor or yaw rate sensor are output together with other DTCs for the steering sensor, inspect and repair the speed sensor and yaw rate sensor first, and then inspect and repair the steering sensor.

PROCEDURE


  1. CHECK DTC


    1. Clear the DTCs Click here.

    2. Turn the power switch off.

    3. Turn the power switch on (IG) and check that no CAN communication system DTCs are output (for LHD: See page , for RHD: Click here.

    4. Drive the vehicle at a speed of 35 km/h (22 mph) and turn the steering wheel to the right and left and check that no speed sensor, yaw rate sensor and steering sensor DTCs are output Click here.

      Result
      Result Proceed to
      DTCs (C1439 and/or C1445) are output A
      CAN communication system DTC is output (for LHD) B
      CAN communication system DTC is output (for RHD) C
      Speed sensor, yaw rate sensor and/or steering sensor DTC is output D
      DTCs (C1439 and C1445) are not output E

      Tech Tips


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

      • If the speed sensor and the yaw rate sensor 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 calibration, such as when the power source voltage drops.


    B

    INSPECT CAN COMMUNICATION SYSTEM Click here

    C

    INSPECT CAN COMMUNICATION SYSTEM Click here

    D

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Click here

    E

    CHECK FOR INTERMITTENT PROBLEMS Click here

    A

  2. CHECK STEERING SENSOR ZERO POINT CALIBRATION


    1. Drive the vehicle straight ahead at 35 km/h (22 mph) or more for at least 5 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 off-centered position of the steering wheel, acquire 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. Turn the power switch off.

    2. Clear the DTCs Click here.

    3. Turn the power switch on (READY).

    4. Drive the vehicle at a speed of 35 km/h (22 mph) or more and turn the steering wheel to the right and left.

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

      Result
      Result Proceed to
      DTCs (C1439 and C1445) are not output A
      Yaw rate sensor and/or steering sensor DTC is output B

      Tech Tips

      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 calibration, such as when the power source voltage drops.


    A

    END

    B

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Click here