Discovery 2. Manual - part 664

 

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Discovery 2. Manual - part 664

 

 

SEATS

DESCRIPTION AND OPERATION

76-5-7

Operation - electric seats

Seat power relay enable line
The BCU provides the seat power relays with an earth supply to the relay coil that enables the relay operation.  When 
this seat power relay enable line is active, the seat power relay energises allowing seat operation. 

In order for the seat power relay to be active the BCU must detect either of the following condition options:

l

Ignition switch in position II.

l

Ignition switch in position II or driver's door within 45 seconds of opening.

Seat fore/ aft movement 
When the cushion switch is operated and the seat power relay enable line is operating, power and earth are supplied 
to the motor in the seat, allowing the seat to move forward or backward depending on switch position. The motor 
drives a gear wheel along a gear rack connected to the seat base. Sliding the cushion switch forward causes the motor 
to drive the seat forward. Sliding the cushion switch rearward reverses polarity of the voltage at the seat motor, driving 
the seat rearward.

Seat cushion front up/ down movement 
When the cushion switch is operated and the seat power relay enable line is operating,  power and earth are supplied 
to the motor in the seat, allowing the front of the seat cushion to move upward or downward depending on switch 
position. The motor drives a gear wheel along a gear rack connected to the seat base. Sliding the front of the cushion 
switch upward causes the motor to drive the seat upward. Sliding the front of the cushion switch downward reverses 
polarity of the voltage at the seat motor driving the seat downward.

Seat cushion rear up/ down movement 
When the cushion switch is operated and the seat power relay enable line is operating, power and earth are supplied 
to the motor in the seat, allowing the seat to move upwards or downwards depending on switch position. The motor 
drives a gear wheel  along a gear rack connected to the seat base. Sliding the rear of the cushion switch upward 
causes the motor to drive the seat upward. Sliding the rear of the cushion switch downward reverses polarity of the 
voltage  at the seat motor driving the seat downward.

Squab fore/ aft movement 
When the squab switch is operated and the seat power relay enable line is operating,  power and earth is supplied to 
the motor in the squab, allowing the squab to move forward or backward depending on switch position. The motor 
drives a gear wheel  along a rotary gear rack connected to the squab. Sliding the squab switch forward causes the 
motor to drive the squab forward. Sliding the squab switch rearward reverses polarity of the voltage at the seat motor 
driving the squab rearward.

Lumbar inflate/ deflate
Sliding the squab switch upwards when the seat power relay enable line is operating applies voltage to the lumbar 
pump. The lumbar pump inflates the lumbar bladder, increasing lumbar support. The lumbar pump and the normally 
closed lumbar deflate solenoid hold the air in the bladder. Sliding the squab switch downwards applies voltage to the 
deflate solenoid, venting the air in the lumbar bladder to atmosphere, decreasing lumbar support.

Diagnostics
TestBook can only verify that the seat power relay line is enabled. It cannot determine the status of the system or any 
of the components.

SEATS

76-5-8

DESCRIPTION AND OPERATION

SEATS

DESCRIPTION AND OPERATION

76-5-9

DESCRIPTION AND OPERATION

Heated seat component location

Heater module
Seat heater switches

SEATS

76-5-10 DESCRIPTION AND OPERATION

Heated seat  block diagram (electric 
seats)

Passenger compartment fuse box
Left seat heater switch
Left seat heater module
Left seat cushion heater element 
Left seat squab heater element 
Right seat heater switch
Right seat heater module
Right seat cushion heater element 
Right seat squab heater element 

 

 

 

 

 

 

 

Content   ..  662  663  664  665   ..