VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1439 and 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 actuator assembly) acquires the steering angle sensor zero point every time the ignition switch is turned to ON and the vehicle is driven at 50 km/h (31 mph) or more for approximately 30 seconds. The ECU also stores previous zero points.

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

DTC No.

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 115 seconds of continuous driving.

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

  • Yaw rate and acceleration sensor (yaw rate sensor)

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 15 km/h (9 mph) or more for 115 seconds or more without the brake pedal being depressed.

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

  • Yaw rate and acceleration sensor (yaw rate sensor)

CAUTION / NOTICE / HINT

Note:

Because this DTC is related to a temporary loss of steering angle zero point calibration, before proceeding with the inspection, it is useful to confirm whether the power source voltage was interrupted by an operation such as removal or disconnection of the battery.

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

  • When a speed sensor or the yaw rate and acceleration sensor (yaw rate sensor) is malfunctioning, 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 a speed sensor or yaw rate and acceleration sensor (yaw rate sensor) are output together with DTCs for the steering angle sensor (spiral with sensor cable sub-assembly), inspect and repair the speed sensor or yaw rate and acceleration sensor (yaw rate sensor) first, and then inspect and repair the steering angle sensor (spiral with sensor cable sub-assembly).

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 DTCs are output (Click here).

    4. Drive the vehicle at a speed of 50 km/h (31 mph) and turn the steering wheel to the right and left and check that no speed sensor or yaw rate and acceleration sensor (yaw rate 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 and/or yaw rate and acceleration sensor DTC is output.

      C

      DTCs are not output

      D

      Tip:
      • If a speed sensor or the yaw rate and acceleration sensor (yaw rate sensor) is malfunctioning, DTCs for the steering angle sensor (spiral with sensor cable sub-assembly) may be stored even though the steering angle sensor (spiral with sensor cable sub-assembly) is normal.

      • If speed sensor and yaw rate and acceleration sensor (yaw rate sensor) DTCs are output simultaneously, repair these malfunctions and then inspect the steering angle sensor (spiral with sensor cable sub-assembly).

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

    INSPECT CAN COMMUNICATION SYSTEM

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS

    USE SIMULATION METHOD TO CHECK

  2. CHECK STEERING ANGLE SENSOR ZERO POINT CALIBRATION

    1. Drive the vehicle straight ahead at 50 km/h (31 mph) or more for at least 30 seconds.

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

      Tip:

      If front wheel alignment and steering 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.

      OK

      The steering wheel is correctly centered.

    ADJUST FRONT WHEEL ALIGNMENT OR STEERING POSITION

  3. REPLACE SPIRAL WITH SENSOR CABLE SUB-ASSEMBLY

    1. Turn the ignition switch off.

    2. Replace the steering angle sensor (spiral with sensor cable sub-assembly) (Click here).

  4. RECONFIRM DTC

    1. Clear the DTCs (Click here).

    2. Turn the ignition switch off.

    3. Start the engine.

    4. Drive the vehicle at a speed of 50 km/h (31 mph) or more for at least 120 seconds 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 DTC is output.

      B

      Tip:

      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 a loss of calibration due to the power source voltage being low.

    END

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS