Air Suspension: Overview

The air suspension system is a four corner system, electronically controlled by a Chassis Control Module (CHCM). The CHCM reacts to inputs from four height sensors and operates an air supply unit and valve blocks.

The air suspension system maintains the vehicle height under all operating conditions by controlling the mass of air in the air springs. The CHCM uses signals from the four height sensors to maintain the correct suspension height, irrespective of vehicle load. Additionally, the system allows the driver to request ride height changes to improve off-road performance or ease of access or loading. This is achieved by the CHCM functioning pneumatic control valves to increase or decrease the mass of air in the air springs.

The air suspension system has four driver selectable, pre-determined ride-height states. A driver interface indicates the selected ride state and height change movement. Additional information is also relayed to the driver via the instrument cluster message center and by audible warnings also transmitted by the instrument cluster.

The air suspension can be controlled manually by the driver using a switch on the floor console to select the required height change.

When doors are open the required height can be achieved by pressing and holding down the height control switch.

For safety reasons, the lowering of the suspension is restricted when a door is open. Full suspension lowering may not be achievable until the door is closed.

The system will temporarily inhibit height adjustments when the vehicle is subject to cornering, heavy acceleration or heavy braking. The inhibit function prevents unsettling of the vehicle.

The air suspension system is controlled by the CHCM. The control module monitors the height of each corner of the vehicle via four height sensors, which are mounted inboard of each road wheel. The control module also performs an 'on-board diagnostic' function to perform 'health checks' on the system. If faults are detected, codes are stored in the control module and can be retrieved using a Land Rover approved diagnostic system.