2002 LAND ROVER DISCOVERY Workshop Manual

SEATS
76-5-8 DESCRIPTION AND OPERATION

SEATS
DESCRIPTION AND OPERATION 76-5-9
DESCRIPTION AND OPERAT ION
Heated seat component location
1Heater module
2Seat heater switches

SEATS
76-5-10 DESCRIPTION AND OPERATION
Heated seat block diagram (electric
seats)
1Passenger compartment fuse box
2Left seat heater switch
3Left seat heater module
4Left seat cushion heater element
5Left seat squab heater element
6Right seat heater switch
7Right seat heater module
8Right seat cushion heater element
9Right seat squab heater element

SEATS
DESCRIPTION AND OPERATION 76-5-11
Description - heated seats
Heated seats
The heated seat system is available on both manual seats and electric seats. The electrical sub-system consists of
the following components:
lSeat heater switches.
lSeat heater elements.
lTemperature control unit (if electric seats are fitted).
lTemperature sensor (if electric seats are fitted).
lThermostat (if manual seats are fitted).
Seat heater switches
The seat heater switches supply an ignition feed to either the temperature control unit (vehicles with electric seats) or
directly to the seat heater elements (vehicles with manual seats). When a seat heater switch is operated, current flows
to the seat heater elements causing them to heat the seat.
The ignition feed comes from fuse 15 in the passenger compartment fuse box.
Seat heater elements
The seat heater elements are located in the seat cushion and squab. The cushion and squab heater elements are
wired in series. Total power consumption at 13.5 volts is approximately 115 Watts.
The cushion heater element has an input feed from the temperature control unit or heater switch and an output to the
squab heater element, which outputs to earth.

SEATS
76-5-12 DESCRIPTION AND OPERATION
Temperature control unit
The temperature control unit is only fitted to vehicles with electric seats. Feed back of the seat temperature is via a
Negative Temperature Coefficient (NTC) sensor within the seat cushion. Resistance of this sensor changes with the
temperature of the seat cushion allowing the temperature control unit to lower or raise the voltage to the seat heater
elements to raise or lower their temperature.
An ignition feed is supplied via the seat heater switch. The temperature sensor supplies an input. Output is a supply
to the cushion heater element and an earth.
Thermostat
On vehicles with non electric seats, the temperature is controlled by a thermostat located in the seat cushion. The
thermostat interrupts the power supply when it reaches a pre-determined temperature.

SEATS
DESCRIPTION AND OPERATION 76-5-13
Operation - heated seats
When the seat heater switch is operated, power is supplied to the heater elements in the seat, causing the seat to
heat up. On vehicles fitted with non electric seats, the thermostat switches the power supply to the heater elements
on and off. On vehicles fitted with electric seats, the temperature control unit senses seat temperature via the sensor
in the cushion and regulates voltage to the seat heater elements to maintain a constant temperature.
On both electric and non electric seats, the heater elements increase and then maintain the seat at a temperature
between 26 and 36
°C (79 and 97 °F).

SEATS
76-5-14 DESCRIPTION AND OPERATION

SEATS
REPAIRS 76-5-15
REPAIRS
Seat - front
$% 78.10.43.99
Remove
1.Disconnect battery earth lead.
2.Remove 3 screws and 1 trim clip securing
lower trim casing to seat.
3.Remove lower trim casing.
4.Remove cap from front seat belt lower
anchorage bolt.
5.Remove front seat belt lower anchorage bolt. 6.Remove 4 Torx bolts and nut securing front
seat to floor.
7.Lean seat forward to gain access to multiplugs.