Land Rover Range Rover Electrical Library Lm 2nd Edition Rover Manual

							DESCRIPTION AND OPERATION
4.26RANGE ROVER
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 (C1637) 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) on 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. 
						

							DESCRIPTION AND OPERATION
RANGE ROVER 4.27
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. For 
more information on door mirror operation, refer to the  Door Mirrors  section of this manual.
 
+  DOOR MIRRORS. 
For more information on steering column operation, refer to the  Steering Column section 
of this manual.
 
+  STEERING COLUMN. 
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 (C1637 & 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 (C1419) 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. 
						

							DESCRIPTION AND OPERATION
4.28RANGE ROVER
FRONT HEATED SEATS
DESCRIPTION
General
Operation of the front electric seats is controlled by the Automatic Temperature Control 
(ATC) ECU via the two centre console mounted switches. Pressing the relevant seat heat 
switch once will heat the seat to a temperature of 44 °C (111 °F) and illuminate two LEDs 
on the switch face. Pressing the seat heat switch a second time will lower the temperature 
to 39 °C (102 °F) and illuminate one LED on the switch face. Pressing the switch a third time 
switches off the seat heat function and extinguishes the remaining LED.
OPERATION
Power Distribution
Feed from the positive battery terminal (C0192) is supplied to fuse 12 and fuse 52 of the 
passenger compartment fuse box (C0632) on an N wire. Fuse 12 (C0586) provides a 
constant battery feed to the ATC ECU (C1629) on an RP wire. Fuse 52 (C0582) provides a 
constant battery feed to the ATC ECU (C0249) on a PU wire. The ATC ECU (C1630) is 
earthed on an N wire. 
RH Seat
When the non-latching RH seat heat switch is pressed, the ATC ECU (C0249) provides a 
feed to the cushion heater matrix (C0969) and the backrest heater matrix (C0971) on GY 
wires. Both matrices are earthed on N wires.
The ATC ECU (C1629) monitors the temperature of the cushion heater matrix (C0969) by 
providing a feed to a Negative Temperature Coefficient (NTC) sensor on a WU wire. The 
sensor is earthed on an N wire. By calculating the resistance of the NTC sensor, the ATC 
ECU can determine the temperature of the seat and regulate the supply voltage to the heater 
matrices accordingly.
LH Seat
When the non-latching LH seat heat switch is pressed, the ATC ECU (C0249) provides a 
feed to the cushion heater matrix (C2090) and the backrest heater matrix (C2091) on GP 
wires. Both matrices are earthed on N wires.
The ATC ECU (C1629) monitors the temperature of the cushion heater matrix (C2090) by 
providing a feed to a Negative Temperature Coefficient (NTC) sensor on a WG wire. The 
sensor is earthed on an N wire. By calculating the resistance of the NTC sensor, the ATC 
ECU can determine the temperature of the seat and regulate the supply voltage to the heater 
matrices accordingly. 
						

							DESCRIPTION AND OPERATION
RANGE ROVER 4.29
REAR HEATED SEATS
DESCRIPTION
General
Operation of the rear electric seats is controlled by the two seat heat switches located on the 
rear face of the centre console. Pressing the relevant seat heat switch once will heat the seat 
to a temperature of 44 °C (111 °F) and illuminate two LEDs on the switch face. Pressing the 
seat heat switch a second time will lower the temperature to 39 °C (102 °F) and illuminate 
one LED on the switch face. Pressing the switch a third time switches off the seat heat 
function and extinguishes the remaining LED.
OPERATION
Power Distribution
Feed from the positive battery terminal (C0192) is supplied to fusible link 1 and fuse 53 of 
the passenger compartment fuse box (C0632) on an R wire. Fusible link 1 (C0588) is 
connected to fuse 11 of the rear fuse box (C2024) by an R wire. Fuse 11 provides a constant 
battery feed to the rear heated seat relay, which is also located in the rear fuse box.
Fuse 53 of the passenger compartment fuse box (C0583) is connected to the ignition switch 
(C0099) by a G wire. When the ignition switch is turned to the ignition position, current flows 
across the switch (C0099 on Td6 vehicles, C0028 on V8 vehicles) to fuse 2 of the passenger 
compartment fuse box (C0585) on a G wire. Fuse 2 (C0587) provides an ignition feed to the 
rear heated seat relay coil (C2022) on a GY wire. The relay coil (C2021) is earthed on an N 
wire. The energised rear heated seat relay (C2021) provides a feed to the LH rear seat heat 
switch (C1401) on a GW wire, and the RH rear seat heat switch (C1403) on a GN wire. Both 
switches are earthed on NB wires.
RH Rear Seat
When the RH rear seat heat switch (C1401) is pressed it provides a feed to the cushion 
heater matrix (C2085) on a WY wire. The heater matrix (C2085) is earthed on an N wire. 
The seat heat switch (C1401) monitors the temperature of the cushion heater matrix 
(C2085) by providing a feed to a Negative Temperature Coefficient (NTC) sensor on a YN 
wire. The sensor is earthed on an N wire. By calculating the resistance of the NTC sensor, 
the switch can determine the temperature of the seat and regulate the supply voltage to the 
RH rear heater matrix accordingly.
LH Rear Seat
When the LH rear seat heat switch (C1403) is pressed it provides a feed to the cushion 
heater matrix (C2084) on a BY wire. The heater matrix (C2084) is earthed on an N wire. The 
seat heat switch (C1403) monitors the temperature of the cushion heater matrix (C2084) by 
providing a feed to a Negative Temperature Coefficient (NTC) sensor on a WN wire. The 
sensor is earthed on an N wire. By calculating the resistance of the NTC sensor, the switch 
can determine the temperature of the seat and regulate the supply voltage to the LH rear 
heater matrix accordingly. 
						

							DESCRIPTION AND OPERATION
4.30RANGE ROVER
DIAGNOSTIC SOCKET
DESCRIPTION
General
The diagnostic socket is located behind an access panel on the drivers side of the fascia. 
The socket is constructed to SAE directive J1962 standard and allows attachment of 
TestBook or T4. The diagnostic socket allows detailed fault diagnosis checks to be carried 
out on the vehicle via an ISO 9141 K Line Bus and the Diagnostic DS2 Bus.
OPERATION
Power Distribution
Feed from the positive battery terminal (C0192) is supplied to fuse 15 and fuse 53 of the 
passenger compartment fuse box (C0632) on an R wire. Fuse 15 (C0586) provides a 
constant battery feed to the diagnostic socket (C0040) on an RUY wire. 
Fuse 53 (C0583) provides a constant battery feed to the ignition switch (C0099 on Td6 
vehicles, C0028 on V8 vehicles) on an R wire. When the ignition switch is turned to the 
ignition position, current flows across the switch (C0099 on Td6 vehicles, C0028 on V8 
vehicles) to fuse 5 of the passenger compartment fuse box (C0585) on a G wire. Fuse 5 
(C0587) provides an ignition feed to the diagnostic socket (C0040) on a GW wire. The 
diagnostic socket (C0040) is earthed on a pair of NB wires.
K Line Bus
The following are connected to the diagnostic socket (C0040) via the K Line Bus on WP 
wires:

Transfer box ECU (C1319).

ABS ECU (C0506).

LH Xenon Lamp ECU (C0009).

RH Xenon Lamp ECU (C0011).

Steering angle sensor (C0862).

Instrument pack (C0233).
Diagnostic DS2 Bus
The following are connected to the diagnostic socket (C0040) via the Diagnostic DS2 Bus:

The V8 ECM (C0331) on WPY and B wires.

The Td6 ECM (C0331) on WPY and B wires.

The ZF automatic transmission ECU (C0932) on a WPY then WP wire. 
						

							DESCRIPTION AND OPERATION
RANGE ROVER 4.31
STARTING AND CHARGING – Td6
DESCRIPTION
Starting
The starting system on the vehicle comprises a 12 V starter motor which drives the engine 
to start the combustion process. The starter converts electrical energy into mechanical 
power. The vehicle electrical system must be capable of supplying sufficient power to enable 
the engine to be cranked.
Range Rover features lazy starting. This entails the driver not having to hold the ignition key 
in the crank position. Starting of the engine is controlled automatically by the Engine Control 
Module (ECM), which provides power to the starter motor until engine speed is greater than 
400 rpm.
Charging
The charging system comprises a battery and an alternator. The battery must be of a 
sufficient capacity to operate the starter motor and operate the various electrical systems in 
the vehicle. The alternator charges the battery when the engine is running and increases its 
output as demand on the battery increases.
CAUTION: The battery positive terminal uses a pyrotechnic attachment which 
detaches the battery cable in the event of a crash severe enough to trigger the 
airbags. Refer to the Supplementary Restraint System section of the System 
Description and Operation Workshop manual for further details.
The alternator is located at the front LH side of the engine, below the steering pump. The 
alternator has an output of 90/150 Amps and is manufactured by Valeo. A polyvee belt 
drives the alternator pulley, which in turn is driven from the engine crankshaft pulley.
The instrument pack incorporates a charge warning lamp which illuminates when there is no 
output or a low output from the alternator. For a detailed description of the starting and 
charging system, refer to the  Engine Management System – Td6  section of the System 
Description and Operation Workshop manual. 
						

							DESCRIPTION AND OPERATION
4.32RANGE ROVER
OPERATION
Power Distribution
Feed from the positive battery terminal (C0192) is supplied to the fuse holder (C1875) on an 
R wire. A constant battery feed is also supplied to fusible link 2 and fuse 53 of the passenger 
compartment fuse box (C0632) on an R wire. 
The 100A fuse located in the fuse holder (C1875) provides a constant battery feed to the 
glow plug timer (C0189) on an R wire. A second 100A fuse in the fuse holder (C1875) 
provides a constant battery feed to the Engine Control Module (ECM) relay (C1895) on an 
R wire.
Fuse 53 of the passenger compartment fuse box (C0583) provides a constant battery feed 
to the ignition switch (C0099) on an R wire. When the ignition switch is turned to the ignition 
position, current flows across the switch (C0099) to fuse 5 of the passenger compartment 
fuse box (C0585) on an G wire. Fuse 5 (C0587) provides an ignition feed to the alternator 
(C0053) on a GW wire.
Fusible link 2 of the passenger compartment fuse box (C0591) is connected to the ignition 
switch (C0099) by an R wire. When the ignition switch is turned to the crank position, 
current flows across the switch (C0099) to the immobilisation ECU (C0059) on a BY wire.
Starting
ECM Relay
The ECM relay coil (C1895) is provided a constant battery feed from the 100A fuse located 
in the fuse holder (C1875) on an R wire. The earth path for the relay coil (C1895) is 
controlled by the ECM (C0603) on an N wire. If the ECM has received a valid remobilisation 
signal from the immobilisation ECU, it will energise the ECM relay. The energised ECM relay 
(C1895) provides a feed to fuse 2 of the engine compartment fuse box (C0570) on an RW 
wire. Fuse 2 (C0570) is connected to the glow plug timer (C0190) by an R then RW wire. 
						

							DESCRIPTION AND OPERATION
RANGE ROVER 4.33
Glow Plug Timer
The glow plug timer receives a constant battery feed from the 100A fuse located in the fuse 
holder (C1875) on an R wire, and a second feed from the energised ECM relay (C1895) via 
fuse 2 of the engine compartment fuse box (C0570) on an R then RW wire.
When all starting parameters have been met, the ECM (C0606) provides a control feed to 
the glow plug timer (C0190) on a BR wire. The glow plug timer (C0190) will now power the 
glow plugs as follows:

Glow plug number 1 (C0476) on a BG wire.

Glow plug number 2 (C0477) on a BP wire.

Glow plug number 3 (C0478) on a BY wire.

Glow plug number 4 (C0479) on a BR wire.

Glow plug number 5 (C1500) on a BW wire.

Glow plug number 6 (C1501) on a BN wire.
All six glow plugs are earthed via their fixings. The glow plug timer (C0190) is earthed on an 
NO wire.
The ECM (C0606) monitors the fault status of the glow plug timer (C0190) via a BY wire.
Starter Motor
The battery (C1641) provides a constant battery feed to the starter motor solenoid (C0178) 
on an R wire. Operation of the starter solenoid is controlled by the immobilisation ECU. 
When the immobilisation ECU (C0059) receives an ignition crank feed from the ignition 
switch (and all other starting parameters have been met) it provides a feed to the starter 
motor solenoid (C0179) on a B then BY wire. The energised starter solenoid allows the 
battery feed to power the starter motor. 
The starter motor (C0823) also provides an engine start signal back to the ECM (C0606) 
on a BG wire.
Fuel Pump
When the engine is started, the ECM (C0331) provides an earth path for the fuel pump relay 
coil (C2022) on a BP wire. The energised fuel pump relay (C2022) provides a feed to the 
fuel pump (C0114) on a WU wire. The fuel pump (C0114) is earthed on an N wire. 
						

							DESCRIPTION AND OPERATION
4.34RANGE ROVER
Charging
The battery (C1641) provides a permanent feed to the alternator (C0183) via the starter 
motor (C0178) on an R wire. Fuse 5 of the passenger compartment fuse box (C0587) 
provides an ignition feed to the alternator (C0053) on a GW wire. 
When the engine is cranked, the alternator (C0053) supplies the ECM (C0606) a Pulse 
Width Modulated (PWM) signal on a U wire. The ECM uses this PWM signal to calculate the 
electrical load on the alternator, and controls engine idle speed accordingly.
When the engine is started, the magnetised rotor within the stator windings generate 3 
phase alternating current (ac) and voltage that rises rapidly with rotor speed. The field 
diodes in the rectifier pack convert the ac current into direct current (dc). Output current from 
the field diodes supplements the initial current flowing through the field windings. This 
causes an increase in the magnetic influence of the rotor, resulting in self-exitation of the 
alternator. The field current increases with rotor speed and thus increases the generated 
current and voltage until the alternator is fully excited. The alternator (C0178) charges the 
battery (C1641) by providing current on an R wire. 
						

							DESCRIPTION AND OPERATION
RANGE ROVER 4.35
STARTING AND CHARGING – V8
DESCRIPTION
Starting
The starting system on the vehicle comprises a 12 V starter motor which drives the engine 
to start the combustion process. The starter converts electrical energy into mechanical 
power. The vehicle electrical system must be capable of supplying sufficient power to enable 
the engine to be cranked.
Range Rover features lazy starting. This entails the driver not having to hold the ignition key 
in the crank position. Starting of the engine is controlled automatically by the Engine Control 
Module (ECM), which provides power to the starter motor until engine speed is greater than 
920 rpm (engine cold) or 680 rpm (engine warm).
Charging
The charging system comprises a battery and an alternator. The battery must be of a 
sufficient capacity to operate the starter motor and operate the various electrical systems in 
the vehicle. The alternator charges the battery when the engine is running and increases its 
output as demand on the battery increases.
CAUTION: The battery positive terminal uses a pyrotechnic attachment which 
detaches the battery cable in the event of a crash severe enough to trigger the 
airbags. Refer to the Supplementary Restraint System section of the System 
Description and Operation Workshop manual for further details.
The alternator is located at the front LH side of the engine. The alternator has an output of 
90/150 Amps and is manufactured by Bosch. A polyvee belt drives the alternator pulley, 
which in turn is driven from the engine crankshaft pulley.
The instrument pack incorporates a charge warning lamp which illuminates when there is no 
output or a low output from the alternator. For a detailed description of the starting and 
charging system, refer to the  Engine Management System – V8 section of the System 
Description and Operation Workshop manual.