automatic transmission LAND ROVER DISCOVERY 2002 Repair Manual

INSTRUMENTS
88-32 DESCRIPTION AND OPERATION
Transmission high temperature warning lamp
The transmission high temperature warning lamp within the instrument pack utilises a red LED and a clear legend.
On vehicles fitted with automatic gearboxes, the transmission high temperature warning lamp is utilised to provide the
driver with a visible warning that the automatic gearbox oil has exceeded a normal operating temperature. The
warning lamp will extinguish if the gearbox oil returns back to normal operating temperature.
When the ignition is switched on, the instrument pack 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 power input for the LED is supplied by the instrument pack via fuse 13. The temperature sensor provides the
earth path to illuminate the transmission high temperature warning lamp.
The transmission high temperature warning lamp is controlled according to the voltage present on the temperature
sensor to instrument panel earth path:
l< 1.8 volts = warning lamp on.
l> 7.7 volts = warning lamp off.

INSTRUMENTS
88-38 DESCRIPTION AND OPERATION
Gearbox manual/sport mode warning lamps
The gearbox manual/sport mode warning lamps within the instrument pack each utilise a green LED and a clear
legend. On vehicles fitted with an automatic gearbox, operating the manual mode switch instructs the Electronic
Automatic Transmission (EAT) ECU to illuminate the manual mode LED. Operating the sport mode switch instructs
the EAT ECU to illuminate the sport mode LED.
There is no self-test performed at ignition on for this warning lamp.
If the EAT ECU detects a fault it will cause both warning lamps to flash.
The power input for the LED's is supplied by the instrument pack. The EAT ECU applies a high or low voltage to the
instrument pack microprocessor which measures the applied voltage from the ECU and illuminates the appropriate
warning lamp.
The voltage on the earth paths from the EAT ECU to the instrument pack has the following functions:
Warning lamp response Manual earth path, volts Sport earth path, volts
No lamps > 7.7 > 7.7
Sport warning > 7.7 < 1.8
Manual warning < 1.8 > 7.7
Both lamps flash < 1.8 < 1.8

INSTRUMENTS
88-42 DESCRIPTION AND OPERATION
Interior rear view mirror with compass
(where fitted)
1Cover
2Electrical connector
3Mounting bracket
4Light sensor
5Compass LED display
6Compass calibration switch
7Compass printed circuit board
Certain vehicles have an interior rear view mirror that features an automatic photochromatic dimming function and an
electronic compass with LED display.
The compass mirror is a self-contained unit and does not interface with any other vehicle system or electronic control
unit. The mirror is fixed to a metal bracket attached to the windscreen.
A three pin connector provides the electrical connection to the mirror's internal circuit board. Pin-1 of the connector
provides the 12V power supply to the board via the auxiliary relay located in the engine compartment fusebox. When
the ignition switch is turned to the 'II' position, a 12V supply is provided to energise the coil of the auxiliary relay via
fuse 26 in the passenger compartment fusebox. The auxiliary relay's contact supply voltage is provided from the
vehicle battery through fusible links 1 & 7. When the relay's contacts close, a 12V supply is fed to the compass mirror
circuit board via fuse 15 in the passenger compartment fusebox. This is the supply voltage feed for the mirror's internal
compass.
Pin-2 of the electrical connector provides the path to earth.
Pin-3 of the electrical connector is a 12V ignition switched supply voltage (position 'II' of the ignition switch). The
supply voltage is provided to the mirror's circuit board via fuse 25 in the passenger compartment fusebox, and the
reverse lamp switch (normally closed) for vehicles with manual transmission or the starter inhibitor / reverse light
switch (normally closed) for vehicles with automatic transmission. This is the supply voltage feed for the mirror's
photochromatic dimming function.
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