Land Rover Range Rover Etm 1997 99 Gems 6th Edition Rover Manual

							SEQUENTIAL MULTIPORT FUEL INJECTION (SFI±V8)A1
CIRCUIT OPERATION2
Mass Air Flow Sensor (X105)
The sensing element of a Mass Air Flow Sensor
(X105) is a ªhot wire anomometerº consisting of two
wires; one heated, one not. The air flows across the
wires, cooling the hot wire and thereby altering its
resistance. The ECM (Z132) measures this change
in resistance and so calculates the amount of air
flowing into the engine.
If the Mass Air Flow Sensor (X105) fails, the engine
will start and then die as the engine reaches 550 rpm
before the ECM (Z132) looks for the Mass Air Flow
Sensor (X105) signal.
Throttle Position Sensor (X171)
This sensor is a variable resistor. The signal informs
the ECM (Z132) of the actual position of the throttle
plate. Failure of the Throttle Position Sensor (X171)
will result in poor idle and lack of throttle response. If
the Throttle Position Sensor (X171) fails in the
ªclosedº mode, then the engine will only rev up to
1740 rpm when the ECM (Z132) will initiate ªover run
fuel cut±offº.
Heated Oxygen Sensors (X139, X160, X289, X290)
The heated oxygen sensor consists of a titanium
metal sensor surrounded by a gas±permeable
ceramic coating. Oxygen in the exhaust gas diffuses
through the ceramic coating on the sensor and
reacts with the titanium wire, altering the resistance
of that wire. From this change in resistance, the
ECM (Z132) can calculate the percentage of oxygen
in the exhaust gas and adjust the injected fuel
quantity that as to achieve the correct air/fuel ratio.
This reduces the emissions of Carbon Monoxide
(CO), Hydrocarbons (HC) and oxides of Nitrogen
(NOX) to acceptable levels.
Presently, two heated oxygen sensors are used, one
in each exhaust down pipe just before the catalyst.
In the event of sensor failure, the system will default
to ºopen loopº. Operation and fuelling will be
calculated using signals from the remaining ECM
inputs. The fault is indicated by illumination of the
malfunction indicator lamp (MIL). ECM diagnostics
also uses heated oxygen sensors to detect catalyst
damage, misfire and fuel system faults.
North American vehicles have two extra heated
oxygen sensors mounted one after each catalyst.
These are used to determine whether the catalysts
are operating efficiently.
Idle Air Control Valve (M112)
The Idle Air Control Valve (M112) controls the idle
speed of the engine by moving the plunger a set
distance, known as a step. Fully open is zero steps
and fully closed is 180 steps. The motor moves each
step by sequentially changing the polarity to each of
the two coils. 
						

							SEQUENTIAL MULTIPORT FUEL INJECTION (SFI±V8)A1
CIRCUIT OPERATION3
Ignition Coils (Z261)
The ignition system on the petrol engine consists of
a ªDISº format, a Direct Ignition System, comprising
of four double ended coils operating on the ªwasted
sparkº technique. The circuit to each coil is
completed via switching within the ECM (Z132),
allowing the coil to charge up and then fire. It
produces sparks in two cylinders simultaneously, one
cylinder on the compression stroke and one on the
exhaust stroke. Due to relatively easy ionisation of
the fuel/air mixture in the cylinder under
compression, the coil will dissipate more energy in
that cylinder than the other, so very little energy is
wasted in the system.
Failure of a coil will result in lack of sparks in two
cylinders (coil 1 feeds cylinders 1/6, coil 2 feeds
cylinders 5/8, coil 3 feeds cylinders 4/7 and coil 4
feeds cylinders 2/3). This results in a misfire.
Injector/Injectors
The fuel injection system used is a ªsequential
multi±pointº system (SFI) i.e. one injector for each
cylinder (compared to ªsingle pointº injection or
throttle body injection which uses one injector only).
A fuel injector consists of a small solenoid which is
activated by the ECM (Z132), allowing fuel to pass
into the combustion chamber. Due to the fuel
pressure in the rail and the shape of the injector
orifice, the fuel squirts into the cylinder in a fine
spray to aid combustion.
Relays
The engine management system uses four relays:
± Starter motor, ECM (Z132) power supply (main
relay), ignition and fuel pump, all located within the
fusebox.
Main Relay
This relay supplies the power feed to the ECM
(Z132) with a tap off to feed the fuel injectors and air
flow meter. This relay is controlled by the ECM
(Z132) itself, so that the ECM (Z132) remains
powered up after the ignition is removed and the
ECM (Z132) can record all temperature readings and
motorise the Idle Air Control Valve (M112) to the fully
open position. This is known as the ªECM (Z132)
power down routineº. Failure of this relay will cause
the ECM (Z132) to not be switched on, resulting in
absence of fuel and spark and therefore a failed
start.Ignition Relay
This relay is ignition key controlled and supplies a
feed to the coils, evaporative emission canister
purge valve and heated oxygen sensor. When the
ignition key is turned off, supply to the coils is cut
immediately.
Starter Motor Relay
This relay is also ignition key controlled and is
activated with the key in the ignition III position only.
Releasing the key after cranking cuts supply to the
relay and switches off the starter motor.
Fuel Pump Relay
This relay is fed from the ignition relay and controlled
by the ECM (Z132). It is pulled in on ignition II
position to prime the fuel system. If the key remains
in the ignition II position, then the relay falls out after
a few seconds, precisely when determined by the
ECM (Z132).
Engine Control Module (ECM) (Z132)
If the ECM (Z132) itself is not working, the entire
engine management system will cease to operate:
no fuel, sparks, tacho reading, etc. 
						

							SEQUENTIAL MULTIPORT FUEL INJECTION (SFI±V8)A1
4CIRCUIT DIAGRAM
30
F 37
20 AP125a
Engine Com-
partment Fuse
Box
[13] A/C Con-
denser
Fan 1
Relay
[14] A/C Con-
denser
Fan 2
Relay
[18] A/C Con-
trol Relay
[19] Engine
Main Con-
trol Relay
RL19
[19]
Not used
Shorting Link 6 2
5
13
RL18
[18]
3
15
4
RL14
[14]
4 C176235 C508
RL13
[13]
4
Not used
Z132
Engine Control
Module (ECM)
E529
See Ground Dis-
tribution S505
S506
17 7 C509
3 C505
5 C50916 910
B
A
A1-6 UR
BB B
2
S501
S515
F
A1-17
UR
NAS 
From VIN
370859
S503
P
Partial
from model year 98
C508
NO
A
Not used
up to model
year 97 
						

							SEQUENTIAL MULTIPORT FUEL INJECTION (SFI±V8)A1
5CIRCUIT DIAGRAM
Shorting Link
1
30
F 39
10 A
B
A1-6
15
30
MF2
30 AP125a
Engine Compart-
ment Fuse Box
[12] Fuel Pump
Relay
[16] Starter Relay
Starting and
Charging
Z132
Engine Control
Module (ECM)
Not used
See Ground Dis-
tribution Not used
RL16
[16]
RL12
[12]
E167 31
5
2
1 C177 2 C17231
WO52
4 C508 1 C508
6 C177
UP NR WR
24 C505
B
S114
Not used
8 C509
8 C508
W
15
F 26
20 A
S504
See Fuse Details 
						

							SEQUENTIAL MULTIPORT FUEL INJECTION (SFI±V8)A1
6CIRCUIT DIAGRAM
14C110
Z132
Engine Control
Module (ECM)
A
A1-4
2 C541
1 C5411
2 C542
1 C542
C
A1-7
2
NO NO
YU
B
A1-5
X135
Inertia Fuel Shut±Off
Switch
[1] Impact Z238
Body Electrical
Control Module
(BECM)
Z134
Fuel Pump Module
[1] Fuel Level Sensor
[2] Fuel Pump
36 13
2 C543
1 C5433
2 C544
1 C544
4 NO NO
30
2 C545
1 C5455
2 C546
1 C546
6 NO NO
17
2 C547
1 C5477
2 C548
1 C548
8 NO NO
18 YW YB YN YG YS YKYR
C505 11 33 32
WP
10 C1142
GB
WU C111 3
M
E167
21
C111
2 3 C110
[1]
0
[1] [2]
See Ground Dis-
tributionPartial S503 K141
Fuel Injectors
WO
1 C503
2 C503
NO
GK
6
K233
Evaporative
Emission Can-
ister Vent Seal
Valve
NAS
from model year
98 
						

							SEQUENTIAL MULTIPORT FUEL INJECTION (SFI±V8)A1
7CIRCUIT DIAGRAM
S503
C
A1-6
D
A1-9
1 C514 2 C514
19 C505Partial2 C50716
Z132
Engine Control
Module (ECM)
NO
SY
Z132
Engine Control
Module (ECM) X105
Mass Air Flow
Sensor K132
Evaporative
Emission Can-
ister Purge
Valve
S502 Partial RBRB 3
C530B RS NO UGNO
Z262
Camshaft Posi-
tion Sensor
2 C530SU
2 1 C531
C531
13 
						

							SEQUENTIAL MULTIPORT FUEL INJECTION (SFI±V8)A1
8CIRCUIT DIAGRAM
Z132
Engine Control
Module (ECM)
NS
X250
Crankshaft Posi-
tion Sensor Z202
Crankshaft Posi-
tion Sensor
Shield
KB 12 C509
S510
E529
See Ground Dis-
tribution
X295
Left Knock Sen-
sor 2 C524
1 C524
KW
RBZ264
Left Knock Sensor
Shield
Z264
Left Knock Sensor
Shield
12 C507
X296
Right Knock
Sensor 2 C523
1 C523
RBZ265
Right Knock
Sensor Shield
Z265
Right Knock
Sensor Shield
11
SCR BY
SCR
SCR
11 C509
S512
10 C507
Z132
Engine Control
Module (ECM)KB
1 C518
Z202
Crankshaft Posi-
tion Sensor
Shield 2 C518 
						

							SEQUENTIAL MULTIPORT FUEL INJECTION (SFI±V8)A1
9CIRCUIT DIAGRAM
13
RB
C513
1 C513
G
S502
36 C507
Z132
Engine Control
Module (ECM)US
X311
Intake Air Tem-
perature Sensor
14
RB SLG
2 C511
1 C511
X126
Engine Coolant
Temperature
Sensor
2 C512
1 C512
X128
Engine Fuel
Temperature
Sensor
RB
35 C507
SW4 C50915 C507
X171
Throttle Position
Sensor
Z132
Engine Control
Module (ECM)
3 C520
RB
D
A1-7
Partial
D C510
15 C505
RG
B
16M112
Idle Air Control
Valve
GW
C
34
OR
A
35
M
2 C5201R
YLG
2
G
A1-18
S516
H
A1-18
NAS
from model year
98
NAS
from model year
98 
						

							SEQUENTIAL MULTIPORT FUEL INJECTION (SFI±V8)A1
10CIRCUIT DIAGRAM
15
F 26
20 A
S509
E529
S510
Z132
Engine Control
Module (ECM)
P125a
Engine Compart-
ment Fuse Box
8 C508
WOU 34 C50733
See Fuse Details
X139
Left Heated Oxy-
gen Sensor Z193
Left Heated Oxy-
gen Sensor ShieldZ194
Right Heated
Oxygen Sensor
Shield
X160
Right Heated
Oxygen Sensor
Z193
Left Heated Oxy-
gen Sensor ShieldZ194
Right Heated
Oxygen Sensor
Shield
Z132
Engine Control
Module (ECM)
RB
S514
SCRWO RBW
WO
SCRS507
PartialA1-11
E
21 C505 32 C507
See Ground Dis-
tribution
1 C526
2 C526
31 C5213
42 C5214 
						

							SEQUENTIAL MULTIPORT FUEL INJECTION (SFI±V8)A1
11CIRCUIT DIAGRAM
15
F 26
20 A
S509
E529
S510
Z132
Engine Control
Module (ECM)
P125a
Engine Compart-
ment Fuse Box
8 C508
WYG 17 C5078
See Fuse Details
X289
Left Heated Oxy-
gen Sensor (Post
Catalyst) Z266
Left Heated Oxy-
gen Sensor (Post
Catalyst) ShieldZ267
Right Heated
Oxygen Sensor
(Post Catalyst)
Shield
X290
Right Heated
Oxygen Sensor
(Post Catalyst)
Z266
Left Heated Oxy-
gen Sensor (Post
Catalyst) ShieldZ267
Right Heated
Oxygen Sensor
(Post Catalyst)
Shield
Z132
Engine Control
Module (ECM)RB
S514
SCRWU RBW
WU
SCR S508
Partial
28 C505
See Ground Dis-
tribution
A1-10E
NAS NAS
NAS
1 C536
2 C536
31 C5353
42 C5354
 
NAS