Seating: Adjustments Jaguar XJ X351

FRONT SEATS ADJUSTMENT

Electric motors are used to provide adjustment of seat slide, seat height, squab recline and, where fitted, cushion tilt, head restraint and cushion extension. An air pump and inflatable cushions are used to provide adjustment of the lumbar support and the squab bolster supports (where fitted).

All of the seat adjustments are controlled from the seat switch pack on the outside of the seat cushion. On non memory seats, the control switches are connected directly to the adjustment motors. On memory seats, the switches are connected to the adjustment motors via a seat control module. Memory seats also have a memory switch pack in the related door panel.

Adjustment Switches

Scheme 1

Memory Switch Pack

Scheme 2

Seat Motors

Each adjustment motor contains a Hall position sensor. The sensors provide position feedback signals which, on seats with a memory function, are used for memory store and recall operation.

The seat slide motor is an integral component of the cushion frame. The motor drives a gear on a worm drive lead screw, which is integral with the floor rail. The lead screw has a stop at each end to limit the fore and aft seat movement.

The seat height motor is located below the seat. The motor drives a gear on a lead screw. The lead screw moves a lever mechanism, which raises or lowers the seat cushion.

The squab recline motor is located in the squab frame. The recline motor rotates a shaft connected to the squab frame, which changes the angle of the squab.

The tilt motor is located below the seat. The tilt motor drives a gear on a lead screw to raise the front of the seat cushion.

The head restraint motor is located in the upper section of the squab frame and is accessible by removal of the seat back. The motor moves a cradle by a rack and pinion arrangement. The cradle has two head restraint stems, which raise and lower the head restraint as the motor moves the cradle.

The cushion extend motor is located below the seat. The motor drives a gear on a lead screw, which extends or retracts the front of the seat cushion.

Lumbar Adjustment

Lumbar adjustment is provided by a lumbar support and air pump installed in the squab. The lumbar support consists of an inflatable cushion with either a single air cell (2-way lumbar support) or dual air cells (4-way lumbar support), depending on vehicle specification. On vehicles with massage seats, the dual cell lumbar support is operated by the air pump of the massage system.

2-way Lumbar Support

Scheme 3

Scheme 4

Squab Bolster Adjustment

Squab bolster adjustment is provided by inflatable cushions on the inside faces of the squab bolsters. The inflatable cushions are operated simultaneously by a solenoid valve block and the air pump of the lumbar support or the massage seat system. On vehicles with massage seats, the squab bolster solenoid valves are incorporated into the valve block containing the slave massage solenoid valves.

Squab and Lumbar Support

Scheme 5