Land Rover Discovery 99my To 03my Electrical Library 3rd Edition Rover Manual

DESCRIPTION AND OPERATION
4.50DISCOVERY SERIES II
Ignition switch supply
With the ignition switch in position II, the feed from fusible link 8 flows through the ignition 
switch to the passenger compartment fusebox on a Y wire.
The feed continues through fuse 25 in the passenger compartment fusebox and is 
connected on a GO wire to the brake pedal switch.
Ignition and Shift Interlock Operation
Ignition interlock
A feed from fuse 20 in the passenger compartment fusebox is connected on a P wire to 
header...

DESCRIPTION AND OPERATION
DISCOVERY SERIES II 4.51
Shift interlock
The shift interlock solenoid is normally in a de-energised state. When the transmission is to 
be moved from the PARK position, the ignition must be on and the brake pedal depressed. 
This energises the solenoid and allows movement of the transmission selector.
When the brake pedal is depressed, the feed from fuse 25 in the passenger compartment 
fusebox flows through the brake pedal switch contacts and is connected to BCU pin C0661-
7 on...

DESCRIPTION AND OPERATION
4.52DISCOVERY SERIES II
Transfer gearbox interlock solenoid
When the BCU senses that the ignition key is removed from the ignition switch, it signals the 
IDM via the serial data bus. The IDM then grants an earth path for the coil of the transfer box 
relay in the passenger compartment fusebox, energising the relay coil and closing the relay 
contacts.
With the contacts closed, a feed from fuse 21 in the passenger compartment fusebox passes 
through the relay and is connected...

DESCRIPTION AND OPERATION
DISCOVERY SERIES II 4.53
CRUISE CONTROL - V8 ENGINES
DESCRIPTION
General
The cruise control is selected from a switch located on the facia. The cruise control operation 
is governed by a cruise control ECU located on the RH A post behind the trim panel. 
Operation is controlled from two switches located on the steering wheel, a set/accelerate 
switch (SET+) and a resume/suspend switch (RES.).
A speed signal is supplied from the SLABS ECU to the cruise control ECU, the cruise...

DESCRIPTION AND OPERATION
4.54DISCOVERY SERIES II
In addition to the feed removal to the ECU when the brake pedal is pressed, a low voltage 
brakelight signal is also sent via the BCU to the cruise control ECU. The brakelight signal 
is also used by the logic circuits in the cruise control ECU, to control the operation of the 
throttle actuator and control/dump valves when the brake pedal has been pressed.
Operation of the resume/suspend switch after a braking event, can restore the operation of 
the...

DESCRIPTION AND OPERATION
DISCOVERY SERIES II 4.55
Cruise Control Operation
When the cruise control switch is on, the feed from fuse 30 in the passenger compartment 
fusebox, passes through the cruise control switch contacts to provide power input to the 
cruise control ECU pin C0239-8 on a WY wire.
Simultaneously, the feed also passes through the cruise control switch indicator lamp which 
illuminates. The indicator lamp is connected to earth on a black wire via header C0760 to 
earth header C0017...

DESCRIPTION AND OPERATION
4.56DISCOVERY SERIES II
Speed signal
The cruise control ECU receives a speed signal input on a KG wire via header C0290 to pin 
C0239-15, from pin C0504-3 on the SLABS ECU.
Cruise set/accelerate
When the set/accel switch is operated, the switch contacts close and connect the feed from 
the horn relay to cruise control ECU pin C0239-4, via the rotary coupler and an RW wire. 
This signal initiates the cruise control ECU to activate the cruise control pump functions, 
providing all...

DESCRIPTION AND OPERATION
DISCOVERY SERIES II 4.57
Other Body Control Unit (BCU) inputs/outputs
Brakelight Signal
If the brake pedal is depressed a pair of contacts in the brake pedal switch allow a feed to 
flow on a GP wire via header C0287 LHD/C0290 RHD to pin C0661-7 on the BCU. The BCU 
sends a brakelight signal output from pin C0661-16 on a GS wire, to pin C0239-5 on the 
cruise control ECU.
The logic circuits in the cruise control ECU use this brakelight signal to lock out the cruise 
control. The...

DESCRIPTION AND OPERATION
4.58DISCOVERY SERIES II
CRUISE CONTROL - Td5 ENGINES
DESCRIPTION
General
Cruise control is integral with the engine management system. Refer to Workshop Manual - 
Engine Management System Td5 - Diesel for description and operation. 

DESCRIPTION AND OPERATION
DISCOVERY SERIES II 4.59
ELECTRONIC AUTOMATIC TRANSMISSION (EAT)
DESCRIPTION
General
The automatic gearbox is a four speed unit with electronic control of gear selection, shift 
quality and torque converter lock-up. A starter/ inhibitor/ reverse light switch on the gearbox 
transmits gear selector position to the EAT ECU, which outputs appropriate signals to an 
electro-hydraulic valve block in the gearbox. The signals from the starter/ inhibitor/ reverse 
light switch are also...