Land Rover Defender V8i Electrical Library Rover Manual

							DESCRIPTION AND OPERATION
DEFENDER V8i4.1
ENGINE IMMOBILISATION
DESCRIPTION
The engine immobilisation system fitted to the Defender 50LE works in
conjunction with the alarm system. The Alarm ECU sends a coded signal to the
Engine Control Module (ECM). If the signal does not match the one expected
by the ECM, the ECM will immobilise the engine.
Passive immobilisation is also fitted, with a passive coil fitted around the
ignition barrel. This will activate 30 seconds after the ignition is turned off and
the drivers door is opened. Alternatively, passive immobilisation will occur 5
minutes after the vehicle is unlocked, or the ignition is turned off. When
attempting to restart the vehicle, passive immobilisation can be switched off
using either the RF handset or EKA code.
OPERATION
Feed from the positive battery terminal is supplied to fusible link 5 in the engine
compartment fuse box (C1217-1) on a brown wire. Fusible link 5 (C570-2) then
supplies a feed to the ignition switch (C28-1) on a brown wire, and fuse 3 of the
passenger compartment fuse box (C580-3), also on a brown wire. The ignition
switch a fuse 3 are connected in parallel.
Fuse 3 of the passenger compartment fuse box (C580-6) supplies a constant
battery input to the Alarm ECU (C61-25) on a purple wire. The Alarm ECU
(C57-11) is earthed on a black wire.
When the ignition switch is turned to position II, a feed is supplied to both fuse
1 (C580-1) and fuse 17 (C581-13) of the passenger compartment fuse box.
These two fuses are connected in parallel via white wires.
Fuse 17 (C581-14) supplies an ignition feed to the Alarm ECU (C61-10) on a
green wire. 
						

							DESCRIPTION AND OPERATION
4.2
DEFENDER V8i
Fuse 1 (C580-2) is connected to the engine Immobilisation warning lamp
(C1192-1) by a white/green wire. The lamp is controlled by the Alarm ECU. The
warning lamp (C1193-1) is connected to the ECU (C61-11) by a red/slate wire.
To illuminate the lamp, the ECU provides an earth. To extinguish the lamp, the
ECU provides a feed equal to that provided by fuse 1, creating a 0 volts
potential difference. In this way, the ECU can control the flashing sequence of
the lamp.
When an ignition feed is received by the Alarm ECU (C61-10), it sends a coded
signal (C61-15) to the ECM (C636-26) on a black wire. If the signal does not
match the one expected by the ECM, the ECM will immobilise the engine. The
Alarm ECU (C57) is also connected to the starter inhibitor/reverse light switch
(C69-4) by a black/orange wire.
The Alarm ECU can be interrogated via the diagnostic socket using TestBook.
The socket (C40-8) is connected to the ECU (C61-17) by an orange/light green
wire.
In addition to the features directly controlled by the Alarm ECU, a passive coil
is fitted around the ignition barrel. This is a user friendly way of re-mobilising
the engine. The passive coil (C672-1) receives a power supply from the Alarm
ECU (C57-7) on an orange/green wire.
The passive coil is only energised when the ignition switch is in position II and
the engine is in an immobilised state. The coil creates a magnetic field that
excites a coil in the RF handset. This causes the handset to transmit a code to
the Alarm ECU to re-mobilise the engine. 
						

							DESCRIPTION AND OPERATION
DEFENDER V8i4.3
ANTI-THEFT ALARM
DESCRIPTION
Although a key is used in the normal way to lock and unlock the vehicle, this
will not fully arm the alarm system. The system is fully armed with an RF
handset, which transmits a rolling code. This code is received by the alarm
ECU. If a door is opened without the alarm ECU receiving the correct signal
from the handset, the alarm will sound.
The Alarm ECU also immobilises the engine, failing to provide a feed to the
starter relay, immobilising the engine.
See Engine Immobilisation.
OPERATION
Feed from the positive battery terminal is connected to the engine compartment
fuse box (C1217-1) by a brown wire. Fusible link 5 (C570-2) provides a feed to
the following;
·The ignition switch (C28-1) on a brown wire.
·Fuse 2 (C580-3) of the passenger compartment fuse box on a brown wire.
·Fuse 3 (C580-3) of the passenger compartment fuse box on a brown wire.
Fuse 2 and 3 are connected in parallel.
Fuse 3 (C580-6) supplies a constant battery feed to the Alarm ECU (C61-25)
on a purple wire. The Alarm ECU is supplied a permanent earth (C57-11) by a
black wire. The alarm ECU (C57-8) also receives a constant battery feed from
fuse 2 (C580-4) on a purple wire. This feed is then used to power the hazard
warning lamps (C57-1 & C57-6) on green/white and green/red wires.
When alarm is armed, the Alarm ECU receives a number of inputs. The RH
door switch (C265-1) is connected to the Alarm ECU (C61-16) by a purple/blue
wire. When the door is closed, the switch is open. In this condition, the Alarm
ECU (C57-5) supplies the BBUS (C666-3) with battery voltage. When the door
is opened, the door switch closes, providing a short to earth. The Alarm ECU
responds by supplying the BBUS with a reduced voltage. Sensing this drop in
voltage, the BBUS sounds. 
						

							DESCRIPTION AND OPERATION
4.4
DEFENDER V8i
The same principle is true of the LH door switch, the tail door switch, and the
bonnet switch. The LH door switch (C106-1) is connected to the Alarm ECU
(C61-5) by a slate/white wire. The tail door switch (C615-1) is connected to the
Alarm ECU (C61-16) in parallel with the RH door switch on a purple/blue wire.
The bonnet switch (C7-2) is connected to the Alarm ECU (C61-9) on a
orange/blue wire, and is provided an earth (C7-1) on a black wire. All 3
switches interact with the BBUS in exactly the same way as the RH door
switch.
In addition to being supplied with a constant battery feed (C666-2) from fuse 2
(C580-6) of the passenger compartment fuse box, the BBUS also has its own
internal power supply, and is earthed (C666-4) on a black wire.
The Alarm ECU (C61-20) also provides a feed for the ultrasonic sensor
(C359-1) on a black/brown wire. The sensor is earthed (C359-2) on a black
wire. When the module detects movement within the vehicle, it supplies the
Alarm ECU (C61-3) with a short series of pulses on a white/black wire. Once
the Alarm ECU detects these pulses, the BBUS is sounded.
To disarm the alarm system, the RF handset is used. The signal transmitted by
the handset is received by the aerial. The aerial is connected to the Alarm ECU
(C61-26) by an orange/slate wire. 
						

							DESCRIPTION AND OPERATION
DEFENDER V8i4.5
The anti-theft alarm LED is used as a visual deterrent, and is connected to the
Alarm ECU (C57-4) by a pink wire. To illuminate the LED, the Alarm ECU
provides a path to earth (C57-11) on a black wire. To extinguish the LED, the
Alarm ECU provides it (C240-1) with a voltage equal to that provided by fuse 3
of the passenger compartment fuse box. As the potential difference across the
LED is now 0 volts, the LED is extinguished. In this way the Alarm ECU can
control the flashing sequence of the LED.
The Alarm ECU also controls the interior lamps. The ECU (C61-1) provides a
feed to the both the front (C355-1) and rear (C356-1) interior lamps on
purple/white wires. An earth is provided for both lamps on black wires.
The alarm system can be interrogated through the diagnostic socket (C40-8),
which is connected to the Alarm ECU (C61-17) by an orange/light green wire. 
						

							DESCRIPTION AND OPERATION
4.6
DEFENDER V8i
STARTING AND CHARGING
DESCRIPTION
The charging system consists of a generator containing a rectifier pack and
regulator to maintain a constant direct (dc) voltage in the system. The
generator is belt driven from the crankshaft and is cooled by a fan mounted
behind the pulley. The generator has a fixed coil wound stator in which a field
coil rotor rotates. Slip rings conduct current to and from the field coils via 2
carbon brushes. The regulator senses output voltage and controls this to
approximately 14 volts.
CHARGING - OPERATION
Feed from the positive battery terminal is connected to fusible link 5 (C1217-1)
of the engine compartment fuse box by a brown wire. Current flows from fusible
link 5 (C570-2) to the ignition switch, also on a brown wire. With the ignition
switch in position II, current flows to fuse 1 (C580-1) of the passenger
compartment fuse box on a white wire.
Fuse 1 (C580-2) supplies a feed to the ignition/no charge warning lamp
(C233-2) on a white/green wire. The warning lamp (C233-5) is earthed via a
diode and generator field windings (C185-1) on a brown/yellow wire. The flow
of current through the warning lamp and field windings partially magnetises the
rotor. A resistor is wired in parallel with the warning lamp to ensure continued
exciter voltage in the event of a bulb failure.
When the engine starts, the magnetised rotor rotates within the stator windings,
generating a 3 phase alternating current (ac) and voltage which rises rapidly
with rotor speed. The field diodes convert the ac current to direct current (dc)
and the generated voltage is fed back to the field windings. As the feed back
voltage increases, the magnetic influence of the rotor also increases, resulting
in self excitation of the rotor. Generated current and voltage increases with
rotor speed until the generator is fully excited.
When the generator outputs a voltage equal to that supplied by the battery, the
warning lamp is extinguished as the potential difference across the lamp is 0
volts. The diode between the generator and warning lamp prevents reverse
flow. 
						

							DESCRIPTION AND OPERATION
DEFENDER V8i4.7
The regulator functions as an electronic control switch on the earth side of the
field coils. The regulator rapidly switches the earth circuit off and on to control
the generated voltage and current to safe limits.
If the battery is in a low state of charge or current draw from the electrical
system is high and causes a voltage drop, the generator charges at its
maximum rate until 14 volts is generated. As battery voltage rises, the
generator current output voltage reduces.
STARTING - OPERATION
With the ignition switch in position II, current flows to fuse 20 (C581-13) of the
passenger compartment fuse box on a white wire. Fuse 20 (C581-20) is
connected to the fuel pump relay coil (C157-2) in the engine management relay
module by a white/green wire. The fuel pump relay coil (C157-1) is earthed
through the ECM (C634-24) on a blue/purple wire.
The ECM earths the fuel pump relay for a short period of time when the ignition
switch is in position II, and continuously during cranking and while the engine
is running.
With the fuel pump relay energised, current from fuse 6 (C574-2) of the engine
compartment fuse box can flow across the relay (C154-7 & C154-4) to the
inertia switch (C123-3) on a white/purple wire. Assuming the inertia switch is
closed, current flows across the switch (C123-1) to the fuel pump (C113-4) on
a white/purple wire. The fuel pump is earthed (C113-3) on a black wire.
When the ignition switch is turned to the crank position, current flows across
the switch (C94-1) to the starter relay coil (C151-85) on a white/red wire. The
relay coil (C151-86) is connected in series to the inhibitor switch (C69-5) by a
black/yellow wire. Assuming the gear selector lever is in the Park or Neutral
position, a route to earth is provided from the inhibitor switch (C69-4) to the
Alarm ECU (C57-10) on a black/orange wire. 
						

							DESCRIPTION AND OPERATION
4.8
DEFENDER V8i
If the engine has been re-mobilised, the Alarm ECU will provide an earth
(C57-11) for the starter relay on a black wire.
Now the starter relay has been energised, a battery feed from fusible link 5
(C570-2) on a brown wire will flow across the relay (C151-87 & C151-30) to the
starter motor (C179-1) on a brown/red wire. This feed will energise the starter
motor solenoid, allowing a battery feed to flow across the solenoid switch and
power the motor. An earth is provided by the starter motor casing. 
						

							DESCRIPTION AND OPERATION
DEFENDER V8i4.9
GENERIC ENGINE MANAGEMENT SYSTEM (GEMS)
DESCRIPTION
GEMS is the engine management system utilised by Defender V8i models,
controlling both the electronic ignition and fuel injection systems. It is able to
alter ignition and fuelling settings to ensure the engine is operating at its
optimum performance for the prevailing conditions. The ECM receives signals
from sensors located around the engine and uses the data to control the fuel
quantity, fuel injection timing and ignition timing in order to achieve optimum
combustion of the fuel mixture in each cylinder.
The main features of the system are as follows:
·A single engine control module (ECM) controls the fuel injection system and
ignition system. The ECM incorporates short circuit protection and can store
intermittent faults on certain inputs. TestBook can be used to interrogate the
ECM for the stored fault codes.
·Fuel is injected sequentially. That is, when the relevant piston is on the inlet
stroke and the intake valve is open.
·The ECM is electronically coded and prevents the engine being started
unless it receives the correct code from the Alarm ECU.
·Detection and correction of engine knock on individual cylinders. The
ignition timing of each cylinder can be varied independently to the other
cylinders and ensures that knock on one cylinder is eliminated without a
detrimental effect on the ignition timing of the other cylinders.
·A diagnostic connector, located below the passenger compartment fuse
box, allows engine tuning or fault diagnosis to be carried out using
TestBook.
·If certain inputs to the ECM fail, a back-up facility enables the engine to
continue running, although at a reduced level of performance.