2002 LAND ROVER DISCOVERY fuel

INSTRUMENTS
88-20 DESCRIPTION AND OPERATION
Low fuel warning lamp
The low fuel warning lamp within the instrument pack utilises an amber LED and a clear legend. The ECM illuminates
the LED when the fuel gauge pointer has reached 8 degrees from zero. The LED remains illuminated until fuel is
added to move the fuel gauge pointer past 20 degrees from zero. This provides the driver with a visible warning that
the fuel level in the tank is low.
When the ignition is switched on, the ECM illuminates the LED to provide a self-check, providing there is no fault it
will remain illuminated for 3 seconds or until the ignition is switched off.
The sender unit resistance thresholds for switching the lamp on and off are shown in the table below:
The power input for the LED is supplied by the instrument pack via fuse 27. The ECM provides the earth path to
illuminate the warning lamp.
Lamp on Lamp off
Resistance, ohms 158 ± 8 113 ± 6
Fuel gauge pointer angle, degrees 8 20

INSTRUMENTS
DESCRIPTION AND OPERATION 88-29
Water in fuel filter warning lamp
The water in fuel filter warning lamp within the instrument pack utilises an amber LED and a clear legend. On vehicles
with diesel engines the LED is illuminated when the water sensor detects water is present in the fuel filter, providing
the driver with a visible warning.
When the ignition is switched on, the instrument pack illuminates the LED to provide a self-check, providing there is
no water present in the fuel filter it will remain illuminated for 3 seconds or until the ignition is switched off.
The power input for the LED is supplied by the instrument pack via fuse 27. The water sensor provides the earth path
to illuminate the warning lamp. The voltage on the earth path from the sensor to the instrument pack is as follows:
l< 1.8 volts = warning lamp on.
l> 7.7 volts = warning lamp off.

INSTRUMENTS
88-30 DESCRIPTION AND OPERATION
Water sensor
On vehicles with diesel engines a water sensor is located in the bottom of the fuel filter. The sensor utilises the
different resistance properties between water and diesel fuel to determines the presence of water in the fuel.
The sensor receives a battery voltage supply from the fuel pump relay. The sensor output is supplied to the instrument
pack. The water sensor provides the earth path to illuminate the warning lamp.
l< 1.8 volts = warning lamp on.
l> 7.7 volts = warning lamp off.