Dtc C1439 Steering Angle Sensor Initialization Incomplete

Brake. Land Cruiser. Urj200, 202 Grj200 Vdj200
Brake Control Dynamic Control Systems. Land Cruiser. Urj200, 202 Grj200 Vdj200

DESCRIPTION

INSPECTION PROCEDURE

CHECK DTC

PERFORM STEERING SENSOR ZERO POINT CALIBRATION

RECONFIRM DTC

DTC C1439 Steering Angle Sensor Initialization Incomplete

DTC C1445 Vehicle Driven with Steering Angle Sensor not Initialized


DESCRIPTION

The skid control ECU (master cylinder solenoid) acquires steering sensor zero point every time the ignition switch is turned to ON and the vehicle is driven at 35 km/h (22 mph) or more for approximately 5 seconds. The ECU also stores the previous zero point.
The steering sensor zero point malfunction warning is canceled by turning the ignition switch off.

DTC Code
DTC Detection Condition
Trouble Area
C1439
After the steering sensor zero point calibration is cleared due to, for example, fluctuations in the power source, the steering zero point calibration cannot be obtained for 60 seconds of continuous driving.
  1. Steering sensor
  2. Yaw rate sensor assembly
  3. Skid control ECU (Master cylinder solenoid)
C1445
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 35 km/h (22 mph) or more for 30 seconds or more without the brake pedal being depressed.

INSPECTION PROCEDURE

NOTICE:
  1. Before proceeding with the inspection, explain to the customer that the output DTC is related to temporary loss of the steering sensor zero point calibration, such as when the power voltage drops when the battery is removed, and confirm that this condition occurred.
  2. After replacing the master cylinder solenoid, perform zero point calibration and store the system information (Click here).
HINT:
When the speed sensor or the yaw rate sensor assembly has trouble, DTCs for the steering sensor may be stored even when the steering sensor is normal. When DTCs for the speed sensor or yaw rate sensor assembly are output together with other DTCs for the steering sensor, inspect and repair the speed sensor and yaw rate sensor assembly first, and then inspect and repair the steering sensor.
1.CHECK DTC

  1. Clear the DTCs (Click here).

  1. Turn the ignition switch off.

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

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

    Result
    Result
    		Proceed to
    DTC is output
    		C1439 and/or C1445
    		A
    Relating to CAN communication system (for LHD)
    		B
    Relating to CAN communication system (for RHD)
    		C
    Relating to speed sensor or yaw rate sensor assembly
    		D
    DTC is not output
    		E

    HINT:
    1. If there is a malfunction in the speed sensor or the yaw rate sensor assembly, an abnormal value may be output although the steering sensor is normal.
    2. If the speed sensor and the yaw rate sensor assembly DTCs are output simultaneously, repair the sensors and inspect the steering sensor.
    3. If DTC C1439 and/or C1445 is not output again, the DTC may have been stored due to a temporary loss of the steering sensor 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
CHECK FOR INTERMITTENT PROBLEMS (Click here)
A


2.PERFORM STEERING SENSOR ZERO POINT CALIBRATION

  1. Drive the vehicle straight ahead at 35 km/h (22 mph) or more for at least 5 seconds.

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

    HINT:
    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).

  1. Turn the ignition switch off.

  1. Start the engine.

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

  1. Check if the same DTC is output (Click here).

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

    HINT:
    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.


B
REPAIR CIRCUITS INDICATED BY OUTPUT DTCS (Click here)
A

END