STEERING COLUMN SYSTEM DETAILS

FUNCTION OF MAIN COMPONENTS

SYSTEM CONTROL

1. The power tilt and power telescopic system has the following control functions:

   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.

CONSTRUCTION

1. Steering Column Assembly (Model with Power Tilt and Power Telescopic System)

   1. The steering column assembly consists of the steering main shaft, tilt motor, telescopic motor and multiplex tilt and telescopic ECU.

      

      Text in Illustration (Models with Power Tilt and Power Telescopic System:)

      *1	Multiplex Tilt and Telescopic ECU	*2	Telescopic Motor
      *3	Steering Main Shaft	*4	Tilt Motor

2. 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 40.0 mm (1.57 in.).

   4. The telescopic adjustment range is 40.0 mm (1.57 in.).

      

3. Power Tilt and Power Telescopic System

   1. A stepless adjustment enables the tilt mechanism to be tilted 69.0 mm (2.72 in.) vertically, and the telescopic mechanism to be moved 45.0 mm (1.77 in.) longitudinally.

      

4. Energy Absorbing Mechanism

   1. The energy absorbing mechanism mainly consists of the breakaway bracket, steering intermediate shaft assembly, steering intermediate shaft sub-assembly No. 2, 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.

      

      Text in Illustration (Before Collision)

      *1	Instrument Panel Reinforcement	*2	Breakaway Bracket
      *3	Column Tube	*4	Steering Intermediate Shaft Assembly
      *5	Steering Intermediate Shaft Sub-assembly No. 2	-	-

   2. When the steering gear assembly moves during a collision (primary collision), the steering intermediate shaft sub-assembly No. 2 contracts, thus helping reduce the possibility of the steering column assembly and the steering wheel protruding into the cabin.

   3. When a collision impact is transmitted to the steering wheel (secondary collision), the steering wheel and the airbag help absorb the impact.

   4. On models with manual tilt and telescopic mechanism, the breakaway bracket and the instrument panel reinforcement separate, and the column tube contracts.

   5. On models with power tilt and power telescopic system, the energy absorbing plate deforms, and the column tube contracts.

      

      Text in Illustration (After Collision)

      *1	Instrument Panel Reinforcement	*2	Breakaway Bracket
      *3	Column Tube	*4	Steering Intermediate Shaft Assembly
      *5	Steering Intermediate Shaft Sub-assembly No. 2	-	-
      	Primary Collision		Secondary Collision

   6. By using a permanently expandable and contractible steering intermediate shaft assembly and a steering intermediate shaft sub-assembly No. 2 that deforms and contracts during collisions, safety during collisions is ensured and a smooth steering feeling is achieved.

      

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 (Driver Side Junction Block Assembly)	Tilt and Telescopic Switch	Position Control ECU	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 control

   *: 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.

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 corresponding Repair Manual for this model.