Front Suspension

ELECTRONIC AIR SUSPENSION - EAS

Description

The Range Rover concept of air suspension is already well established, the system fitted to the New Range Rover is broadly similar. Progressive development has resulted in added features to improve the control and operation of the system.

Air springs provide a soft and comfortable feel to the ride of the vehicle. The use of a microprocessor to control the system exploits the advantages of air suspension.

The system provides a near constant ride frequency under all load conditions resulting in:

^ Improved ride quality
^ Consistency of ride quality
^ Constant ride height
^ Improved headlamp levelling

The system provides five ride height settings plus self levelling. Each setting is automatically maintained at the correct height by the system logic with the minimum of driver involvement. Vehicle height is sensed by four rotary potentiometer type height sensors. Height information from each sensor signals the electronic control unit (ECU) to adjust each air spring by switching the solenoid valves to hold, add or release air.

The five height settings are as follows:

Standard: Profile
Low profile: 25 mm (1 in) below standard.

Access: 65 mm (2.6 in) below standard. Crawl: It is possible to drive at the access ride height at speeds less than 32 km/h (20 mph), where headroom is restricted.

High profile: 40 mm (1.6 in) above standard.

Extended profile: 70 mm (2.75 in) above standard. This setting is not manually selectable.

Self levelling

On a coil sprung vehicle the effect of adding weight is for the vehicle to lean either from front to back or side to side unless the increased weight is evenly spread. With air suspension, the system detects this body lean and automatically compensates for it. The vehicle will self level to the lowest corner height for 20 seconds each time the driver exits vehicle and closes the doors.

The system will check vehicle height every 6 hours and make minor corrections, not exceeding 8 mm, (0.31 in) as necessary.

When unloading through the tailgate the system will self level to compensate for the decreased load after door closure.

NOTE: If the vehicle is parked on uneven ground or with a wheel or wheels on the curb, self levelling will lower the vehicle to the lowest spring height

CAUTION: The underside of the vehicle must be kept clear of any obstacles while the vehicle is parked, as self levelling may result in a reduced trim height.

WARNING: Before commencing work which requires access to the underside or wheel arches of the vehicle, the suspension must be allowed to relevel. Relevelling is achieved by opening and closing of any of the side doors, while all other doors and tail gate remain closed, and the ignition off.

GEAS must be set in 'high-lock' using Testbook, during any work which does not require chassis to axle displacement. This will hold the suspension in extended profile position, until reset by Testbook.