Discovery 2. Manual — part 243

SEATS

DESCRIPTION AND OPERATION

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1 Ignition switch
2 BCU
3 Driver door switch
4 Left seat power relay
5 Left seat satellite fuse box
6 Left seat switch pack
7 Left seat fore/ aft motor
8 Left seat cushion front up/ down motor
9 Left seat cushion rear up/ down motor

10 Left seat squab fore/ aft motor
11 Left seat lumbar pump

12 Left seat lumbar deflate solenoid
13 Right seat power relay
14 Right seat satellite fuse box
15 Right seat switch pack
16 Right seat fore/ aft motor
17 Right seat cushion front up/ down motor
18 Right seat cushion rear up/ down motor
19 Right seat squab fore/ aft motor
20 Right seat lumbar pump
21 Right seat lumbar deflate solenoid
22 Passenger front door switch

SEATS

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DESCRIPTION AND OPERATION

Description - electric seats

General
All markets use the same electric seat system. Electically operated lumbar support is optional. The system consists
of an electrical sub-system and a mechanical sub-system.

The electrical sub-system consists of the following components:

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BCU.

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Seat power relays.

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Seat switch packs.

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Seat fore/ aft motors.

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Seat cushion front up/ down motors.

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Seat cushion rear up/ down motors.

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Seat squab motor.

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Lumbar pump.

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Lumbar deflate solenoid.

The mechanical sub-system consist of the following components:

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Gear wheels.

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Rack and pinion assemblies.

Seat power relay

Located beneath the seat, the seat power relay supplies battery voltage to the satellite fuse box. Operation of the
relays is controlled by the BCU.

Voltage to the seat power relays is from fuse 5 in the engine compartment fuse box. The BCU controls the earth for
the relay coils. Operating the seat power relays provides voltage to the satellite fuse box under each seat.

Satellite fuse box
Located beneath the seat, the satellite fuse box provides circuit protection for the wiring to the seat switches and
motors. It also protects the lumbar inflate and deflate circuits.

The seat power relay provides voltage directly to the 40A fuse in the satellite fuse box. Voltage from this fuse feeds
the seat switch pack. The 3A fuses in the satellite fuse box protect the wiring to the lumbar pump and lumbar deflate
solenoid. Voltage to the 3A fuses comes from the seat switch pack.

SEATS

DESCRIPTION AND OPERATION

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Seat switch pack

Each seat switch pack contains two switches representing the seat cushion and the seat squab. The switches provide
the following adjustments:

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Seat fore/ aft.

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Cushion front up/ down.

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Cushion rear up/ down.

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Squab fore/ aft.

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Lumbar inflate.

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Lumbar deflate.

The voltage supply to the seat switch pack is from the 40A fuse in the satellite fuse box. A pair of switches controls
the operation of each seat motor, the lumbar pump and the lumbar deflate relay.

SEATS

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DESCRIPTION AND OPERATION

Seat fore/ aft motor

The seat fore/ aft motor is a permanent magnet motor coupled to a rack and pinion assembly. Should the motor seize
or stick for 6 seconds or more, an internal thermal cut out switch will trip to remove voltage from the motor. Reset
time for the switch is 35 seconds.

Two pins within the seat switch pack control the seat fore/ aft motor. Both pins are normally earthed. Operating the
backward switch applies voltage to that pin while the other pin remains earthed. Operating the forward switch reverses
power and earth to the motor allowing the motor to run in the opposite direction.

Seat cushion front up/ down motor
The seat cushion front up/ down motor is a permanent magnet motor coupled to a rack and pinion assembly. Should
the motor seize or stick for 6 seconds or more an internal thermal cut out switch will trip to remove voltage from the
motor. Reset time for the switch is 35 seconds.

Two pins within the seat switch pack control the seat cushion front up/ down motor. Both pins are normally earthed.
Operating the up switch applies voltage to that pin while the other pin remains earthed. Operating the down switch
reverses power and earth to the motor allowing the motor to run in the opposite direction.

Seat cushion rear up/ down motor
The seat cushion rear up/ down motor is a permanent magnet motor coupled to a rack and pinion assembly. Should
the motor seize or stick for 6 seconds or more, an internal thermal cut out switch will trip to remove voltage from the
motor. Reset time for the switch is 35 seconds.

Two pins within the seat switch pack control the seat cushion rear up/ down motor. Both pins are normally earthed.
Operating the up switch applies voltage to that pin while the other pin remains earthed. Operating the down switch
reverses power and earth to the motor allowing the motor to run in the opposite direction.

Seat squab fore/ aft motor
The squab fore/ aft motor is a permanent magnet motor coupled to a rotary rack and pinion assembly. Should the
motor seize or stick for 6 seconds or more, an internal thermal cut out switch will trip to remove voltage from the motor.
Reset time for the switch is 35 seconds.

Two pins within the seat switch pack control the squab fore/ aft motor. Both pins are normally earthed. Operating the
fore switch applies voltage to that pin while the other pin remains earthed. Operating the aft switch reverses power
and earth to the motor allowing the motor to run in the opposite direction.