L322 Range Rover System Description and Operation
INSTRUMENTS
88-6
DESCRIPTION AND OPERATION
Description
General
The instrument packs fitted to all New Range Rover models are similar and only differ in the following features:
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mph or km/h speedometer
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tachometer maximum rev/min band.
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mph or km/h odometer and trip display
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message centre language display
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ambient temperature display
°
C or
°
F.
The instrument pack is a totally electronic device which receives analogue or digital signals via hardwired or bus
systems for instrumentation operation.
The signals are processed by two microprocessors which transpose the data into analogue gauge indications or
warning lamp illumination. The pack is connected to the vehicle electrical system by three connectors which provide
all input and output connections for instrument pack operation.
No internal components of the instrument pack are serviceable, with the only changeable parts being five 1.5W bulbs,
at the rear of the pack, which are used for LCD backlighting illumination.
The instrument pack has two main functions; to provide information to the driver of the vehicle status and to process
and relay digital signals from and to other system controlling ECU's.
The instrument pack features the following displays:
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Tachometer - large analogue display
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Speedometer - large analogue display
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Fuel gauge - small analogue display
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Engine coolant temperature gauge - small analogue display
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Engine service data - LED illuminated
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Gearbox/transfer box status indicator - LED illuminated
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Odometer - LCD
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Trip meter - LCD
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Ambient temperature - LCD
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Message centre - LCD.
The instrument pack also features a number of warning lamps. The warning lamps illuminate in one of four colours
which indicate the level of importance of the warning as follows:
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Red = Warning
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Amber = Caution
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Green = System operative
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Blue = Headlamp main beam operative.
Warning Lamps
The warning lamps are located in two groups at the left and right hand side of the pack. The direction indicators and
main beam warning lamps are located at the top of the display and the glow plug, DSC and HDC warning lamps are
located above the message centre, between the two large analogue gauges.
The warning lamps can be split into two groups; self controlled and externally controlled.
Self controlled lamps are dependant on software logic within the instrument pack for activation. The pack software
controls the lamp check illumination at ignition on and all lamps whose operation is wholly controlled by the pack, the
low fuel level warning lamp for example.
Externally controlled lamps are supplied with a current from another system controlling ECU or triggered by the pack
on receipt of a bus message from another ECU.
Some lamps are activated by an external ECU, but the control logic is retained within the pack. For example, the
direction indicator warning lamps are synchronised and controlled by the LCM, but the lamp illumination logic is
retained within the pack. These lamps are shown in the following table as being self and externally controlled.
