Front Seats

FRONT SEATS

DESCRIPTION

General
Two levels of electric front seats are fitted to Range Rover, with a memory function available as an option. The memory function is capable of storing up to three seat positions. The standard electric front seats have four motors to control the following:
^ Horizontal movement
^ Seat height
^ Seat angle
^ Seat backrest recline.

The higher specification 'Contour' seat has two additional motors which control the following:
^ Headrest movement
^ Additional upper backrest adjustment.

OPERATION

Power Distribution
Feed from the positive battery terminal (C0192) is provided to the seat relay and fuse 53. Both are located in the passenger compartment fuse box (C0632). Fuse 53 (C0583) provides a constant battery feed to the ignition switch (C0028 on V8 vehicles) on an R wire.

When the ignition switch is turned to the 'ignition' position, current flows across the switch (C0028 on V8 vehicles) to the seat relay coil (C0585) on a G wire. Current flows through the seat relay coil (C0583) to earth on an N wire. This energises the seat relay. The energised seat relay provides a feed to fuse 20 and fuse 21, which are also located in the passenger compartment fuse box.

Non-Memory Drivers Seat
Fuse 20 (C0584) provides a feed to the LH seat switch pack (C0773) on an RN wire. Fuse 21 (C0584) provides a feed to the RH seat switch pack (C0774) on an RN wire. Both the LH (C0773) and the RH (C0774) seat switch packs are earthed on N wires.

Memory Drivers Seat
Fuse 20 (C0584) provides a feed to the seat memory ECU (C0722) on an RN wire, and the upper backrest motor (C2308) on an RN then R wire. The seat memory ECU (C0722) is earthed on an N and an NB wire. The upper backrest motor (C2308) is earthed on an N wire.

NOTE: The upper backrest motor is only fitted on the 'Comfort' seat.

RH Front Seat

Horizontal Movement
A single seat motor controls horizontal movement of the RH front seat. To move the seat forwards and backwards, the RH seat switch pack (C0774) provides feeds to the forward/ backward seat motor (C0721) on GY and BY wires.

Vertical Movement
Two seat motors are used to control vertical movement of the RH front seat; one for the front of the seat, and one for the rear. To move the front of the seat up and down, the RH seat switch pack (C0774) provides feeds to the front up/down motor (C0097) on PR and UR wires. To move the rear of the seat up and down, the RH seat switch pack (C0774) provides feeds to the rear up/down motor (C0475) on UG and PG wires.

Recline
A single seat motor controls RH front seat backrest recline. To recline the backrest, the RH seat switch pack (C0774) provides feeds to the recline motor (C0718) on GP and BP wires.

Upper Backrest
A single seat motor controls movement of the RH front seat upper backrest. To move the upper backrest, the RH seat switch pack (C0774) provides feeds to the motor (C1418) on GR and GU wires.

LH Front Seat

Horizontal Movement
A single seat motor controls horizontal movement of the LH front seat. To move the seat forwards and backwards, the LH seat switch pack (C0773) provides feeds to the forward/ backward seat motor (C0720) on GY and BY wires.

Vertical Movement
Two seat motors are used to control vertical movement of the LH front seat; one for the front of the seat, and one for the rear. To move the front of the seat up and down, the LH seat switch pack (C0773) provides feeds to the front up/down motor (C0097) on PR and UR wires. To move the rear of the seat up and down, the LH seat switch pack (C0773) provides feeds to the rear up/down motor (C1636) or UG and PG wires.

Recline
A single seat motor controls LH front seat backrest recline. To recline the backrest, the LH seat switch pack (C0773) provides feeds to the recline motor (C0518) on GP and BP wires.

Upper Backrest
A single seat motor controls movement of the LH front seat upper backrest. To move the upper backrest the LH seat switch pack (C0773) provides feeds to the motor (C1419) on GR and GU wires.

Memory Drivers Seat
When the memory function is selected, the seat memory ECU (C0722) transmits the relevant data along the K-bus to the Body Control Unit (BCU) (C0660) on a WRY wire. The BCU then moves both the steering column and the door mirrors to the required position.

Horizontal Movement
When the memory function is selected, the seat memory ECU (C0772) provides feeds to the forward/backward seat motor (C0720) on a pair of R wires. The seat memory ECU (C0772) monitors the position of the seat by measuring the voltage pulses returned from the hall effect sensor (C0720) on an R wire.

Vertical Movement
When the memory function is selected, the seat memory ECU (C0772) provides feeds to the front (C1637) and rear (C1636) up/down motors on R wires. The seat memory ECU (C0772) monitors the position of the seat by measuring the voltage pulses returned from the hall effect sensors (Cl637 & C1636) on R wires.

Recline
When the memory function is selected, the seat memory ECU (C0772) provides feeds to the backrest recline seat motor (C0518) on a pair of R wires. The seat memory ECU (C0772) monitors the position of the seat by measuring the voltage pulses returned from the hall effect sensor (C0518) on an R wire.

Headrest
When the memory function is selected, the seat memory ECU (C0772) provides feeds to the headrest seat motor (0419) on a pair of R wires. The seat memory ECU (C0772) monitors the position of the headrest by measuring the voltage pulses returned from the hall effect sensor (C1419) on an R wire.