VEHICLE STABILITY CONTROL 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 acquires the steering angle sensor zero point every time the ignition 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 cancelled 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 sensor zero point calibration cannot be obtained for 60 seconds of continuous driving.

  • Steering angle sensor

  • Yaw rate and acceleration sensor

  • Brake actuator assembly (Skid control ECU)
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 35 km/h (22 mph) or more for 30 seconds or more without the brake pedal being depressed.

  • Steering angle sensor

  • Yaw rate and acceleration sensor

  • Brake actuator assembly (Skid control ECU)

INSPECTION PROCEDURE

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

Tech Tips


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

  • When the speed sensor or the yaw rate and acceleration sensor has trouble, DTCs for the steering angle sensor may be output even when the steering angle sensor is normal. When DTCs for the speed sensor or yaw rate and acceleration sensor are output together with other DTCs for the steering angle sensor, inspect and repair the speed sensor and yaw rate and acceleration sensor 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 on (IG) again and check that no CAN communication system DTCs are output Click here.

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

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

      Tech Tips


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

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

      • 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 source voltage drops.


    B

    INSPECT CAN COMMUNICATION SYSTEM Click here

    C

    REPAIR CIRCUIT INDICATED BY OUTPUT DTC Click here

    D

    CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) 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.

      Tech Tips

      If 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 ignition switch off.

    2. Clear the DTCs Click here.

    3. Start the engine.

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

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

      Result
      Result Proceed to
      DTCs (C1439 and C1445) are not output A
      Yaw rate and acceleration sensor and/or steering angle sensor 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 source voltage drops.

      • If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step Click here.


    B

    REPAIR CIRCUIT INDICATED BY OUTPUT DTC Click here

    A

    END