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...

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...

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,...

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...

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...

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...

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...

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...

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...