STEERING COLUMN SYSTEM DETAILS

  1. FUNCTION OF MAIN COMPONENTS

    Component Function
    Multiplex Tilt and Telescopic ECU Calculates position information and operating condition using signals from the position sensor, the tilt and telescopic switch and the CAN network, and controls the tilt motor and telescopic motor.
    Tilt Motor and Telescopic Motor Adjusts the position of the steering column assembly according to the voltage output of the multiplex tilt and telescopic ECU.
    Tilt Position Sensor and Telescopic Position Sensor Detects the rotation signal of the tilt motor and telescopic motor and informs the multiplex tilt and telescopic ECU.
    Tilt and Telescopic Switch Sends a switch signal to the multiplex tilt and telescopic ECU depending on the switch operation.
    Main Body ECU Requests operating permission from the multiplex tilt and telescopic ECU.
    Position Control ECU Assembly Sends the memorized position information to the multiplex tilt and telescopic ECU.

  2. SYSTEM CONTROL

    1. This system has the following control functions, thus providing excellent ease of operation and entry/exit.

      Control Outline
      Manual Control The tilt and telescopic positions can be adjusted using the tilt and telescopic switch.
      Automatic Control* Auto Away The steering wheel automatically tilts up and retracts all the way when the engine switch is turned from on (ACC) or on (IG) to off.
      Auto Return When the engine switch is turned from off to on (ACC) or on (IG), the steering wheel automatically returns to the previous position which was set before the engine switch was turned off.
      Memory Control The memory function can store the driver seat position and tilt and telescopic position. Up to 2 memory positions can be stored in the system memory and recalled. 2 positions can be saved for the seat memory switch.

      Tech Tips

      *: Customize settings can be changed.

  3. CONSTRUCTION

    1. Manual Tilt and Telescopic Mechanism

      1. The manual tilt and telescopic mechanism allows adjustment of the steering wheel position in the vertical and longitudinal (extending and retracting) directions through lever operation. This provides the driver with the most comfortable driving position.

      2. The manual tilt and telescopic mechanism is locked using the tilt and telescopic lever.

      3. The tilt adjustment range is 4.4°.

      4. The telescopic adjustment range is 40 mm (1.57 in.).

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    2. Power Tilt and Power Telescopic System

      1. A stepless adjustment enables the tilt mechanism to be tilted 4.4° vertically, and the telescopic mechanism to be moved 40 mm (1.57 in.) longitudinally.

        A0039TKE01

    3. Energy Absorbing Mechanism

      1. The energy absorbing mechanism mainly consists of the breakaway bracket, intermediate shaft, and column tube. The steering column assembly is mounted on the instrument panel reinforcement via a breakaway bracket. The steering column assembly and the steering gear assembly are connected with a contractile intermediate shaft.

      2. When the steering gear assembly moves during a collision (primary collision), the intermediate shaft contracts, thus helping reduce the possibility of the steering column assembly and the steering wheel protruding into the cabin.

        A0039Q4E01

      3. When a collision impact is transmitted to the steering wheel (secondary collision), the steering wheel and the airbag help absorb the impact. In addition, the breakaway bracket separates, and the column tube contracts. At this time, the friction resistance of the sliding portion, which is staked to the column tube, absorbs the energy. This sequential energy absorbing mechanism helps absorb the impact of the secondary collision.

        A0039ZNE01

  4. FAIL-SAFE

    1. When the multiplex tilt and telescopic ECU detects a malfunction in the power tilt and power telescopic system, the ECU changes the control mode to a fail-safe mode as follows:

      Detection Item Fail-safe
      Key Code Confirm Signal Malfunction Auto away and auto return function stops.
      Tilt Position Sensor or Tilt Motor Circuit Malfunction Tilt operation is suspended.
      Telescopic Position Sensor or Telescopic Motor Circuit Malfunction Telescopic operation is suspended.
      ECU Power Source Circuit Malfunction Tilt and telescopic operations are suspended.

    2. If a communication problem has occurred in any ECUs related to the multiplex tilt and telescopic ECU and the power tilt and power telescopic system, the power tilt and power telescopic system allows the following controls to continue:

      Control ECU for which communication is lost
      Power Management Control ECU Main Body ECU Tilt and Telescopic Switch Position Control ECU Assembly Related to all ECUs
      Manual Control ○ X* X ○ X*
      Automatic Control Auto Away X X ○ ○ X
      Auto Return X X ○ ○ X
      Memory Control ○ X ○ X X

      Tech Tips

      ○: Controls

      X: Does not controls

      *: The operation is permitted if the engine switch is on (IG) while the signal from the main body ECU is interrupted. The operation is prohibited if the engine switch is off while the signal from the main body ECU is interrupted.

  5. DIAGNOSIS

    1. If the multiplex tilt and telescopic ECU detects a malfunction in the power tilt and power telescopic system, the ECU stores the malfunction data in memory. Then, by connecting the intelligent tester II to the DLC3 terminal, the Diagnostic Trouble Codes (DTCs) can be accessed and an active test can be performed to test the operation of the tilt motor and the telescopic motor. For details, refer to the AVENSIS Repair Manual.