AIR SUSPENSION
AIR PIPE COLOUR CODES
ECU INPUTS
The following pipes have a coloured band to aid
assembly:
The air suspension system is controlled by the ECU,
which operates dependent on driver selected inputs
plus those listed below. In each mode the ECU
maintains the requested ride height by adjusting the
volume of air in one or more of the air springs.
Component .................................................... Colour
Rear left spring .................................................... RED
Rear right spring................................................ BLUE
Front left spring ............................................ YELLOW
Front right spring ............................................ GREEN
Reservoir ....................................................... BROWN
Exhaust .......................................................... VIOLET
Battery - 12 volt supply from ignition load relay.
Engine - from A.C. generator phase tap, signals
engine speed to ECU. Note that engine must be
running for all height changes, except access and
self-levelling when parked. The compressor will be
disabled if engine speed falls below 500 rev/min. This
is to prevent the compressor drawing current from the
battery when the A.C. generator is not charging.
SYSTEM OPERATION
-
see RR3858M
Height sensors - four potentiometer height sensors
provide suspension height signals to the ECU.
Air is drawn through the inlet filter 1. to the
compressor 2., where it is compressed to 10.0 ± 0.5
bar.
Road speed - the vehicle speed sensor provides
information enabling height changes to occur at
correct road speed. Input speed signal to ECU is from
a buffer unit located in the driver’s side footwell.
Compressor operation activates the diaphragm
solenoid valve 12. to prevent air going straight to
atmosphere.
Interior light delay unit - signals ECU if any door, not
tailgate, is opened, which immediately suspends all
height changes.
Compressed air passes to the air drier 3. Moisture is
removed as air flows through the drier desiccant. The
desiccant in the drier becomes wet.
Parkbrake switch, manual vehicles - the Parkbrake
must be ON to enter ACCESS.
Dried air passes to the valve block, through NRV1 to
the reservoir 4.
Gearbox inhibit switch, automatic vehicles - the
transmission must be in park to enter ACCESS,
Parkbrake on or off.
The three non-return valves 6. ensure correct air flow.
They also prevent loss of spring pressure if total loss
of reservoir pressure occurs.
Footbrake switch (brake light) - when footbrake is
applied, and for one second after release, all height
levelling is suspended below 1.6 kph (1 mph) and
above 8 kph (5 mph). The purpose of this is to prevent
the system reacting to suspension movement caused
by weight transfer during braking and to prevent
suspension wind up during height change. Note that
this inhibit function is removed after sixty seconds e.g.
if footbrake is held on for this time.
A pressure switch 5. maintains system pressure
between set limits by switching the compressor on
and off via an ECU controlled relay.
For air to be admitted to any spring or springs, inlet
valve 7. and the relevant air spring solenoid valve or
valves 9. must be energised.
For air to be exhausted from any spring, the exhaust
valve 8. and the relevant air spring solenoid valve or
valves must be energised.
The diaphragm solenoid valve ensures that air
exhausted to atmosphere passes through the drier.
This action purges moisture from the desiccant and
regenerates the air drier.
Air is finally exhausted through the system air
operated diaphragm valve 13. and to atmosphere
through a silencer 14. at the chassis rear
cross-member.
DESCRIPTION AND OPERATION
7
| Categories | Land Rover, Range Rover |
|---|---|
| Tags | Land Rover |
| Model Year | 1995 |
| Download File |
|
| Document Type | Owners Manual |
| Language | English |
| Product Name | Range Rover Classic |
| Product Brand | Land Rover |
| Document File Type | |
| Publisher | landrover.com |
| Wikipedia's Page | http://en.wikipedia.org/wiki/Land_Rover |
| Copyright | Attribution Non-commercial |
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