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 (brake booster with master cylinder assembly) acquires the steering angle sensor zero point every time the power switch on (READY) and the vehicle is driven at 35 km/h (22 mph) or more for approximately 5 seconds. The skid control ECU (brake booster with master cylinder assembly) also stores the previous zero point.

If front wheel alignment or the steering wheel position is adjusted without disconnecting the cable from the negative (-) auxiliary battery terminal, or if the yaw rate and acceleration sensor zero point is not acquired after the adjustments have been completed, the skid control ECU (brake booster with master cylinder assembly) detects the difference between the previous zero point and newly acquired zero point and stores this DTC to indicate a poor adjustment.

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

DTC No. Detection Item INF Code DTC Detection Condition Trouble Area Note
C1439 Steering Angle Sensor Initialization Incomplete 752 The steering angle sensor zero point is lost (due to instability of supplied power, etc.) and cannot be acquired by the skid control ECU (brake booster with master cylinder assembly).

  • Steering angle sensor

  • Yaw rate sensor (airbag sensor assembly)

 VSC DTC
C1445 Vehicle Driven with Steering Angle Sensor not Initialized 753 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 15 km/h (9 mph) or more for 60 seconds or more without the brake pedal being depressed.

  • Steering angle sensor

  • Yaw rate sensor (airbag sensor assembly)

 VSC DTC

PROCEDURE


  1. CHECK DTC


    1. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    2. Turn the power switch off.

    3. Turn the power switch on (IG) again and check that no CAN communication system DTC is output.

      Click here

    4. Turn the power switch on (READY).

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

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes

      Tech Tips


      • When CAN communication system DTCs are output, repair the CAN communication system before repairing each corresponding sensor.

      • 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 these malfunctions 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 source voltage drops.

      Result
      Result Proceed to
      DTCs C1439 and/or C1445 are output. A
      CAN communication system DTCs are output. B
      Speed sensor, yaw rate and acceleration sensor and/or steering angle sensor DTCs are output. C
      DTCs C1439 and C1445 are not output. D

    B

    INSPECT CAN COMMUNICATION SYSTEM Click here

    C

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Click here

    D

    USE SIMULATION METHOD TO CHECK Click here

    A

  2. CHECK STEERING ANGLE 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.

      OK
      The steering wheel is centered correctly.

      Tech Tips

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

      Result
      Proceed to
      OK
      NG

    NG

    ADJUST FRONT WHEEL ALIGNMENT OR STEERING POSITION Click here

    OK

  3. RECONFIRM DTC


    1. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    2. Turn the power switch off.

    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 output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTCs C1439 and C1445 are not output. A
      Yaw rate and acceleration sensor and/or steering angle sensor DTCs are output. B

      Tech Tips

      If DTCs C1439 and/or C1445 are 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 source voltage drops.


    A

    END

    B

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Click here