Description - SLS (REAR SUSPENSION)

REAR SUSPENSION

64-12

DESCRIPTION AND OPERATION

Description - SLS

General
The Self Levelling Suspension (SLS) system is an optional fitment and comprises an Electronic Control Unit (ECU), 
air supply unit, two air springs and two height sensors. The SLS system only operates on the rear suspension and is 
designed to keep the vehicle level to compensate for uneven loads or when towing. The system controls the gap 
between the chassis and the rear axle to a tolerance of 

±

 0.5 mm (0.02 in). The ride height of the rear of the vehicle 

can be controlled in three modes of operation; normal ride height, Off-Road Mode (ORM) and extended mode. A 
transportation mode, initiated using TestBook, is also available for moving the vehicle on a trailer.

The system is controlled electronically by an ECU which is shared with the ABS system and known as the Self 
Levelling and Anti-Lock Braking System (SLABS) ECU. The system operates by using an air supply unit to inflate or 
deflate the air springs to maintain a constant ride height.

An accessory remote handset is available to remotely operate the SLS system to allow easier connection and 
disconnection of trailers.

Two SLS system warning lamps are located in the instrument pack. The warning lamp in the bottom left corner of the 
instrument pack is the SLS warning lamp. If a fault is detected in the system, the warning lamp will illuminate 
continuously in an amber colour. The warning lamp also flashes in an amber colour when the remote handset is being 
used. The second warning lamp, located in the top right of the instrument pack is the ORM warning lamp. When ORM 
is selected the warning lamp is continuously illuminated in an amber colour. When the SLS is between standard ride 
height and ORM or in extended mode, the warning lamp will flash. Standard ride height, measured between the tip of 
the axle bump stop rubber and the axle, is 61.5 mm (2.42 in). ORM ride height, measured between the tip of axle 
bump stop and the axle, is 100 mm (3.93 in).

A switch is located in the group of six switches on the fascia and is used to select the ORM. The switch is non-latching 
and must be depressed for a minimum of 0.5 seconds to signal the ECU that ORM has been requested.