L322 Range Rover System Description and Operation
LIGHTING
86-2-8
DESCRIPTION AND OPERATION
Description
General
The exterior lighting is controlled by the Light Check Module (LCM). The LCM controls the following vehicle functions:
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Control and monitoring of exterior lamps including direction indicators and hazard warning functionality
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Illumination dimmer control of instrument pack and all interior switch illumination
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Communication and control and monitoring of trailer lighting via the trailer ECU
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Control of power supply to automatic headlamp levelling ECU (only with bi-xenon headlamps option)
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Monitoring and evaluation of check control inputs from other system ECU's and output of applicable messages
in the instrument pack message centre.
The LCM is connected to the I Bus and communicates with other vehicle systems via the instrument pack. The LCM
contains a microprocessor which performs the control, monitoring and evaluation functions.
Light Check Module (LCM)
The LCM is located on the RH 'A' post, behind the trim panel. The LCM is connected to the vehicle wiring harness
with three multiplugs.
The LCM receives two permanent battery power supplies via the passenger compartment fusebox and power feeds
from the ignition switch positions I (AUX) and II (IGN).
The lighting circuits are not protected by conventional fuses. The control circuitry within the LCM for each individual
circuit can detect and isolate a problem circuit.
A monitoring system within the LCM can determine a bulb failure and indicate this to the driver via the instrument pack
message centre. The following table shows the bulbs monitored by the LCM and their type and rating:
