Air Suspension System System Description

  1. REAR AIR SUSPENSION SYSTEM DESCRIPTION

  1. ADAPTIVE VARIABLE SUSPENSION DESCRIPTION

  1. FUNCTION OF MAIN COMPONENTS

Air Suspension System -- System Description



REAR AIR SUSPENSION SYSTEM DESCRIPTION
  1. This system uses pneumatic cylinders. The suspension control ECU analyzes the information based on the switches, sensors and input signals, operates the compressor assembly and uses the solenoid valves to control the vehicle height.
  2. The suspension control ECU detects, via the height control sensor, changes in the rear vehicle height that result from the number of occupants or the amount of load. Then, the suspension control ECU controls the height control valves and compressor assembly in order to automatically adjust the rear vehicle height to a constant (normal) vehicle height.
  3. Three vehicle heights can be selected by operating the height control switch: HI, NORMAL and LO. The HI vehicle height ensures performance on rough roads. The LO vehicle height facilitates the entry and exit of the occupants and the loading and unloading of cargo. The normal vehicle height helps realize excellent controllability and riding comfort during normal driving.

ADAPTIVE VARIABLE SUSPENSION DESCRIPTION

  1. The suspension control ECU receives signals from the sensors and switches to control the absorber control actuators. It uses these signals to optimally control the damping force in accordance with the driving conditions and road conditions.


FUNCTION OF MAIN COMPONENTS

Component
Function
Absorber Control Switch
Selects the damping force of the shock absorbers (SPORT, normal, COMF).
Acceleration Sensor
Detects the front right or left body vertical accelerated motions.
Absorber Control Actuator
Changes the damping force of the front shock absorber.
Height Control OFF Switch
Used to operate or stop height control.
Height Control Switch
Used to select the vehicle height.
Height Control Sensor
Convert vertical changes in the rear vehicle height, in proportion to the standard, to signals and detects vehicle height.
Height Control Indicator
Displays the current vehicle height (HI, N, LO).
Height Control OFF Indicator
Comes on during height control OFF mode.
Height Control Compressor
Generates compressed air that is necessary to raise vehicle height and supplies it to the pneumatic cylinder assemblies.
Exhaust Solenoid Valve (Height Control Compressor)
Discharges compressed air from the pneumatic cylinder assemblies to lower the vehicle.
Leveling Solenoid Valve (No. 2 Height Control Valve)
Adjusts the air pressure in the pneumatic cylinder assembly to raise or lower the vehicle height.
Gate Solenoid Valve (No. 2 Height Control Valve)
Opens or closes the passage between the pneumatic cylinder assembly LH and RH.
Suspension Control ECU
  1. Estimates the vehicle condition based on the signals from sensors and switches and outputs control signals to the compressor and valves.
  2. When changed to the diagnostic mode, indicates any malfunction by outputting DTCs.
  3. Detects the front left body vertical accelerated motion.
Suspension Control Relay (AIR SUS)
Supplies electricity to the compressor motor.
Main Body ECU
Receives signals from the door courtesy light switches and sends them to the suspension control ECU through CAN communication.
ECM
Sends the engine speed signal to the suspension control ECU through CAN communication.
Skid Control ECU
Receives signals from the stop light switch and speed sensors and sends them to the suspension control ECU through CAN communication.