dashboard LAND ROVER DISCOVERY 2002 Workshop Manual

ENGINE MANAGEMENT SYSTEM - TD5
DESCRIPTION AND OPERATION 18-1-35
Cruise control master switch
The cruise control master switch is located on the dashboard. When the driver activates the switch it requests the
cruise control system to be active. The switch acts as a latching switch, on the first operation of the switch the cruise
control system is activated, when the switch is pressed again the cruise control system is de-activated. The cruise
control warning lamp is part of the switch and illuminates when the switch is activated.
Input/Output
Input to the cruise control master switch is 12 volts via the main relay. When the switch is pressed the circuit is
completed by the ECM providing an earth path for the relay via pin 15 of connector C0658 of the ECM.
The cruise control master switch can fail as follows:
lOpen circuit.
lShort circuit to voltage supply.
lShort circuit to vehicle earth.
lWiring loom fault.
In the event of a cruise control master switch failure cruise control does not operate.

INSTRUMENTS
DESCRIPTION AND OPERATION 88-15
Instrument illumination
Dimmer switch
The instrument pack contains 3 bulbs to illuminate the dials. Depending on market the bulbs are illuminated either
from the side lamps feed with no dimmer control or from a PWM dimmer control located on the dashboard. A PWM
dimmer is used so finer control of the instrument illumination can be achieved.
The input is either direct from the side lamp power feed or from the PWM dimmer control. The instrument pack
provides the earth path to illuminate the lamps.