Air suspension (EAS)

Last updated: 18 June 2012

The L322's Electronic Air Suspension (EAS) replaces steel springs with air springs at all four corners, giving a variable ride height and a famously smooth ride while retaining serious off-road articulation. It is one of the car's defining features, and, with age, its single most common source of faults.

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Photo/diagram: air spring, compressor & valve block

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Key takeaway: The air suspension is brilliant when healthy and a known weak point when neglected. Most faults are well understood and fixable — diagnose before converting to coils.

AT A GLANCE Benefit: superb ride + adjustable height · Risk with age: the #1 L322 fault area · Golden rule: read live height data before replacing parts

Ride heights

Setting	Height	Use
Access mode	lowered	Drops the car for easy entry/loading (at rest)
Standard	172 mm	Normal on-road ride height
Off-road	227 mm	Raised for rough terrain
Extended	max	Hold the button for extra height when off-road isn't enough

If the car "bellies out" off-road, the control system senses reduced load on the air springs and automatically raises ride height to maximise articulation.

Cross-linking

A clever feature that debuted on the L322 in 2002: the cross-linked?Cross-linking opens electronic valves connecting the air lines of diagonally/laterally adjacent springs. When one wheel lifts off-road, air pushes the opposite wheel down — mimicking the articulation of a live axle. air system. Electronic valves can connect adjacent air springs so that, when one wheel is lifted off-road, the opposite wheel is forced down. Recreating the articulation benefit of a traditional live axle while keeping independent suspension's on-road comfort.

How it works

An air compressor (under the rear, by the spare) feeds a reservoir and the four air springs.
A valve block directs air to each corner.
Height sensors at each wheel report ride height to the control module.
The module maintains level and adjusts height by driving mode and speed.

Common faults

Most faults share one symptom: a "SUSPENSION INACTIVE" message, slow or no raising, being stuck in standard mode, or limp-home mode. The car is ~2.5-3 tonnes, so the system works hard. Typical causes:

Cause	Notes
Air spring (bag) leak	Perished bellows; a corner sags overnight. Most common cause.
Valve block leak	Internal seals leak; system can't hold/build pressure.
Compressor wear	Worn compressor can't build pressure; slow rise.
Height sensor fault	False readings; uneven or failed levelling.
Exhaust valve sticking	Can prevent lowering, or pump only one end.

Diagnosis & fixes

GOLDEN RULE No EAS component should be replaced on symptom alone. Read individual height-sensor live data first — many parts get changed needlessly. A proper diagnostic that reads EAS faults is essential; a cheap code reader is not enough.

Confirm whether the system is losing air (leak) or failing to build pressure (compressor/valve).
Listen for hissing at the bags and valve block; inspect the compressor.
Some owners convert to coil springs to escape recurring faults — at the cost of ride quality and height adjustment.

TIP A quick lock-to-lock steering turn, or raising/lowering the suspension a few times, can sometimes clear a basic "air suspension inactive" warning — but recurring faults need proper diagnosis.

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