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System Description

  1. AIR SUSPENSION SYSTEM DESCRIPTION 
    1. The suspension control ECU operates the compressor motor with the dryer and uses the solenoid valves to control the vehicle height by analyzing the information based on the switches, sensors and input signals
    2. Through the 4 height control sensors, the suspension control ECU detects changes in the vehicle height that result from the number of occupants or the amount of the load Then, the suspension control ECU controls the height control solenoid valves and the compressor motor with the dryer in order to automatically adjust the vehicle height to a constant (normal) level. Furthermore, 2 vehicle heights can be selected by operating the height control switch- HEIGHT HIGH and NORMAL.
    3. In cases such as when the vehicle is jacked up, the auto leveling function is prohibited by turning the power switch OFF In cases when the vehicle is to be jacked up with the power switch ON (READY), the height control function can be stopped by connecting terminals 11 (OPA) and 4 (CG) of the DLC3.
    4. The absorber control switch selects the shock absorber damping force (COMFORT, NORMAL or SPORT).

      Function of components 

      COMPONENTS FUNCTION CHART

      Component Function
      Suspension Control Actuators Changes the damping force
      Suspension Control Relay (AIR SUS) Supplies electricity to the compressor motor
      Height Control Solenoid Valves Supplies and discharges compressed air to and from air chambers in 4 pneumatic cylinders (front left and right, rear left and right)
      Height Control Compressor Supplies compressed air to increase the vehicle height
      Exhaust Solenoid Valve Discharges compressed air from the pneumatic cylinders to lower the vehicle
      Height Control Sensors Detects the vehicle height and displacement volume of the suspension caused by unevenness of the road
      Front Acceleration Sensor LH Detects the front left body vertical accelerated motion
      Rear Acceleration Sensor Detects the rear body vertical accelerated motion
      Height Control Indicator Light Displayed on the combination meter when the height control switch position is on HEIGHT HIGH
      Height Control Switch Selects the vehicle height (NORMAL / HEIGHT HIGH)
      Absorber Control Indicator Light Comes on indicating that damping force is in "SPORT or COMFORT" mode by the absorber control switch, and warns that a malfunction has occurred in the suspension control system
      Absorber Control Switch Selects the damping force (COMFORT / NORMAL / SPORT)
      Skid Control ECU Receives the signals of the stop light switch and speed sensor, and sends them to the suspension control ECU
      ECM Receives the signals of the throttle opening angle, shift lever position, and IC regulator, and sends them to the suspension control ECU
      Suspension Control ECU
      • Controls the damping force and vehicle height according to the operation modes
      • Blinks the absorber control indicator light to warn the driver when the ECU detects a malfunction in the suspension control system
      • When changed to the diagnostic mode, indicates any malfunction by DTCs (Diagnostic Trouble Codes)
      • Detects the front right body vertical accelerated motion
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