1998 JAGUAR X308 idle control valve

High
tension (electrical)
ht
Hourh
Hydro

carbon
HC
I
Idl

e Air Control
IACEl
ectrical control of throttle bypass air
Idl

e Air Control Valve
IACVStepper motor dri
ven device which vari
es the volume of air by-passing the
throttle to maintain the programmed idle speed
Ignitionign
Ignition am
plifier
IAD
evice which amplifies the i
gniti
on system output
Ignition groundIGN GND
In

ertia Fuel Shut-off
IFSAn
inertia system that shuts off the fuel supply when activated by pre-
determined force limits brough t about by (e.g.) collision
In
ertia Fuel Shut-off
Switch
IFSSShut
s down fuel and ignition systems in the event of a vehicle impact
Inta

ke air
Air drawn t
hrough a cleaner and distri
buted to each cylinder for use in
combustion
InputI/PAn
electrical input signal to a controlling device
Inta

ke Air Temperature
IATTem
perature of intake air
Inta

ke Air Temperature
Sensor
IATSDe
vice used to measure IAT
Inta

ke Air Temperature
Sensor Ignition
IATSITherm
istor which signals the ECM to retard
the ignition timing in response to
high inlet air temperatures
Inta
ke Air Temperature
Sensor Injection
IATSFTher
mistor which inputs air density information to the ECM
Internal diameteri.

dia
Inte

rnational Standards
Organization
ISO
K
Kilogramme (mass)kg
Kilogram
me (force)
kg
f
Ki

logramme force per
square centimeter
kg
f/cm2
Kilom

eter
km
Ki

lometer per hour
km
/h
Kilopasc

al
kP
a
KilovoltkV
Knock

Sensor
KSSens
or which detects the onset of detonation, and signals the ECM to retard
the ignition
L
Le
ft-hand
LH
Left-hand drive veh

icle
LHD
Le

ft-hand thread
LH Thd
Ligh

t Emitting Diode
LEDLigh
t-emitting semiconductor diode used
in alphanumeric displays and as an
indicator lamp
Liqu
id Crystal Display
LCDOp
tical digital display system, applied voltage to which varies the way the
crystals reflect light, thereby modifying the display
LiterL
Low ten
sion
ltPrim
ary circuit of the ignition system, linking the battery to the primary
winding in the ignition coil
M
Malfu
nction Indicator
Lamp
MILA
required on-board indicator to aler
t the driver of an emission related
malfunction
Mani
fold Absolute
Pressure
MAPAbsolute pressure o
f the intake manifold air
Mani

fold Absolute
Pressure Sensor
MAPSSensor loca
ted in the ECM and
ported to the intake manifold
Manifol
d Surface
Temperature
MST
Mass Ai
r Flow
MAFSy
stem which provides inform
ation on the mass flow rate of the intake air to
the engine
Mass Ai
r Flow Sensor
MAFSHot-wi
re sensor which monitors air flow
into the intake manifold for fueling
and ignition control
Maxim
um
max.

Tacho
meter
TACHA
ci
rcuit that provides input for
an electronic tachometer display
Thermal Vacuu
m Valve
TVVControls vacuum l
e
vels or
routing based on temperature
Throttle
Body
TBDe
vi
ce containing the throttle
Throttl
e
Position
TP
Throttl
e
Position Sensor
TPSInterprets throttl
e

position and movement to iden tify idle, acceleration and
full-power demands
Top Dead CenterTDC
Torque Converter C
lutch
TCC
To
tal
indicator reading
TIRThe t
o
tal indicated movement on a DTI with the test piece rotated through
360°
Transm
ission Control
Module
TCMControls
the shifting pattern
of the (automatic) transmission
Transm
ission Control
Switch
TCSModifi es
the operation of electronically controlled transmissions
Transmission Oil
TemperatureTOTIndi
cat
es temperature of transmission fluid
Transmission RangeTRThe ran
g
e in which the transmission is operating
Transmission Spe
e
d
Sensor
TSSIndi cat
es rotational speed of transmission output shaft or turbine shaft
V
Vacuu
m
Solenoid Valve
VSVVacuu
m
operated valve used in the speed control system
Vacuu
m
Solenoid Valve
(atm)
VSV VAVacuu m
atmospheric valve used in the speed control system
Vacuu
m
Solenoid Valve
(rel)
VSV VRVacuu m
release valve used in the speed control system
Vacuu
m
Solenoid Valve
(vac)
VSV VVVacuu m
valve used in the speed control system
Variable Valve TimingVVTA
s
ystem by which the relationship of the crankshaft and camshaft may be
altered during engine running
Vehi cl
e Battery Adapter
VBAProvide
s
electrical power to the PDU
and supplies a battery reference level
Vehicl
e Condition Monitor
VCMInst
rum
ent panel display which warns of faults
Ve
hic
le Emission Control
Information Label
VECI Label
Vehi cl
e Identification
Number
VINN u
mber assigned to the vehicle by the manufacturer, primarily for licensing
and identification purposes
Vehi cl
e Interface Adapter
VIAExtends the
PDU ca
pability and provid
es a parallel interface to vehicle
harnesses and ECMs
Vehicle Spe e
d Sensor
VSSSens
or which provides ve
hicle speed information
Viscosity In
dexVI
Voltage RegulatorVRDe
vice which regulates the variable output voltage of a generator
W
Wat
tWSI unit of power (1 hp = 7
45.7 watts)
W
i
de Open Throttle
WO
TFu
ll throttle position

The
measurement of the maximum system pressure, (which is
governed by the pressure relief valve) is achieved by
inserting the Service Tool (pressure gauge and adaptors) into th e fluid circuit of the power steering system. Run the engine
at idle speed, turn the st eering from lock to lock and read the ma ximum pressure recorded on the gauge.
Installin
g Test Equipment
To
in
stall the pressure test equipment:
Pla
c
e a suitable drain tray be
low the power steering pump.
Install a hose clamp on
the re
servoir to pump hose prior to disconnecting any hoses, to avoid unnecessary loss of
fluid.
Disc
onnect the hose from the power st
eering pump high pressure outlet.
Install the pu
mp outlet to hose adaptor (5
). Do not omit the 'O' ring seal (9).
Connect the power steering
pump
adaptor to control valve hose (6) of the test equipment.
Install th e adaptor (4) in th
e high
pressure hose previously removed from the power steering pump outlet.
Conn
ect the connector (3) of the test equipment hose (2) to the adaptor (4).
R
e
move the hose clamp fro
m the reservoir hose.
Start th
e engine.
With the control valve (7) OPEN and the engine idli ng, the following system pressures may be checked:
Du
ring turning.
W
h
en the steering is
held on full lock.
With
the steeri
ng at rest.
• CAUTIONS:
To avoid excessive heating of the po wer steering pump, do not close the valve for longer than 5 seconds maximum.
Do not drive the vehicle with the test equipment installed.
With the control valve (7) CLOSED the power steering pump maximum ou tput pressure can be checked.
Removing Test Equipment
To
remove the test equipment:
Install a hose clamp
on
the reservoir to power steering pump hose.
Re
movi
ng the test equipmen
t is a reversal of the in stallation instructions.
Install a new '
O
' ring seal (9) to the power steering pump high pressu
re outlet to hose connection.
Instal
l the original hose to
the power steering pump.
Re
move the clamp from the reservoir to
the power steering pump hose.
Top-up the reservoir flui
d.
Ble
e
d the power steerin
g system. For additional information,
REFER to Power Steering System Bleeding
- in thi
s section.
Stee
ring Fault Diagnosis by Sympt
om Charts
Leakage
52
11-0
11-03/1
Pump High Pressure Ou
tlet
to Hose Adaptor
621
1
-011-02
Pump Adaptor
to Contro
l Valve Hose
721
1
-011-01
Control Valve
82
11-
011
Pressure Gauge
9-'O
'
Ring Seal
Cond
iti
on
Possib
l
e Sources
Acti
o
n
Co
nfirm
the position of the fluid
leak.
CLEAN th
e area of the leak.
In
s
pect the area and confirm the exact position of leak.
Make sure the fluid
is not from anoth
er system on
the vehicle.

E
ngine Management System Components
Electronic Throt
tle
The
electronic throttle assembly, in resp
onse to signals from both the driver and the ECM, adjusts idle speed, sets the
throttle valve to the position requested by the driver's accelerator / throttle pedal, cruise and traction control, power
limitation and catalyst warm-up.
Mass
Air Flow Meter
The sensor i
s located in the air flow mete
r assembly and outputs an analogue voltag e to the ECM. This sensor measures air
flow into the engine inlet system and is calibrated to measure kg / hour.
In
take Air Temperature
Th
e intake air temperature sensor is loca
ted in the air flow meter assembly and outputs an analogue voltage to the ECM.
The ECM will substitute a default value eq ual to 50°C should this sensor fail.
Fuel Injectors
The eigh
t bottom fed fuel injectors are located in the fuel rails. Th
e fuel injectors are electromagnetic solenoid valves
controlled by the ECM. The pulse time for the injector combined with the fuel pr essure determines the volume of fuel
injected to the manifold.
Fue
l Delivery
The fu
el pump provides fuel to the fuel rail where the circulat
ing pressure is controlled by a pressure regulator valve; excess
fuel is returned to the fuel tank.
The pressure regulator valve is controlled by manifold depression so that fuel delivery pressure is maintained at
approximately 3 bar above manifold pressure.
Fuel Pump
Relay
The ECM controls thi

s component for normal
engine running. The security system may disable this relay via communication
with the ECM.
Fuel Lev
el Sensing
The tank fuel

is measured by the fuel le
vel sensor . This signal is used by the ECM as an in put to certain diagnostics.
Eva
porative Valve
Excess vapour

formed in the fuel tank is
absorbed into the evaporative emission pu rge control canister. While the engine is
running, the fuel absorbed in the canister is gradually purged back into the engine. The rate of purging is governed by
engine operating conditions and vapour concentration level. Operating conditions which affect the purge rate are:
2—Purge
valve
3—Engine

torque reduction
4—E

lectronic throttle assembly
5—Coo

ling fans
6—Ignition amplifier driver
7—Engine overspeed
8—Cli

mate control compressor clutch
9—O

BDII information (J1962, CAN, ISO)

10—F
uel pump relay
11—Heat

ed oxygen sensor
12—Vari

able valve timing
13—MIL sw

itching



ECM Out
puts
It

em
Par
t Number
De
scription
1—Exhaus

t gas recirculation

2.2. Cruise
3. 3. Mechanica l
guard
4. 4. Fixed idle
5. 5. Redundancy
6. 6. Full authority
7. 7. Engine shut-down
Normal mode occurs when the EC M uses the mechanical and monitoring arrangem ent of the throttle valve to control throttle
opening. The ECM does not permit driver demand to be exceeded but it can be restricted to allow for such features as
stability / traction control, or engine power limitation.
The ECM determines engine idle speed by controlling the throttle valve motor to vary the blade angle between the non-
adjustable preset limits of the mechanic al guard and the throttle valve motor.
Cruise mode is engaged as a result of the ECM calculating and controlling the required throttle valve opening via the
vacuum system. When the driver releases the throttle pedal, the input shaft disengages from the mechanical guard or the
vacuum actuator pulls the guard away from th e throttle valve. The throttle pedal will feel light should it be pushed again to
accelerate (pressing the pedal further will re-engage the input shaft with the mechanical guard and restore normal feel).
The ECM utilizes sensors to monitor the relative positions of the mechanical guard and throttle valve and adjusts them to
maintain the set cruise speed.
Mechanical guard mode permits full mechanical operation of the throttle if the ECM detects that a problem has been
encountered with the throttle valve position sensor, dc motor, associated harnesses / connecto rs or the ECM.
Fixed idle mode occurs when any two of the three sensors (two input shaft sensors and the mechanical guard sensor) fail.
The ECM will assume values which represent a blade angl e of approximately 2,5° and 1200 rpm (unloaded) maximum
engine speed.
Redundancy mode occurs when any one of the three sensors (two input shaft sensors and the mechanical guard sensor)
fails. The operational pair will be deemed to be safe to co ntinue without intervention, but cruise will be inhibited.
Full authority mode is invoked when a mech anical guard failure occurs which indicates that the guard is stuck fully open.
The red warning lamp will be lit and road speed will be li mited to 120 kph.
Engine shut-down mode will occur followin g multiple failures, such as mechanical guard mode following full authority mode
(or vice versa) or the throttle blade sticks.
Intake Elbow

The intake elbow directs the metered airflow from the electronic throttle to the intake manifold. Stub pipes on both sides of

leak
/blockage
EVAP valve failure


P0444Evaporati

ve emissions system
(EVAP) valve circuit open circuit
EVAP t
o ECM drive circuit open
circuit or high resistance
EVAP failu
re
F
or evaporative emissions pinpoint
tests,
REFER to Section 303
-1
3 Evaporative

Emiss
ions
.
P0445Evaporati

ve emissions system
(EVAP) valve circuit short circuit
E
VAP to ECM drive circuit short
circuit to ground
EVAP failu
re
F
or evaporative emissions pinpoint
tests,
REFER to Section 303
-1
3 Evaporative

Emiss
ions
.
P0447Cani

ster close valve (CCV) circuit
open circuit
CCV to ECM
drive circuit open
circuit, high resi stance or short
circuit to ground
EVAP failu
re
F
or evaporative emissions pinpoint
tests,
REFER to Section 303
-1
3 Evaporative

Emiss
ions
.
P0448Cani

ster close valve (CCV) circuit
short circuit
CCV to
ECM drive circuit short
circuit to high voltage
CCV failure

F
or evaporative emissions pinpoint
tests,
REFER to Section 303
-1
3 Evaporative

Emiss
ions
.
P0452F

uel tank pressure (FTP) sensor
circuit low voltage
FTP
sensor disconnected
FTP

sensor to ECM sense circuit
open circuit or short circuit to
ground
FTP sen
sor to ECM power supply
circuit open circuit or short circuit
to ground
F
TP sensor failure
F
or evaporative emissions pinpoint
tests,
REFER to Section 303
-1
3 Evaporative

Emiss
ions
.
P0453F

uel tank pressure (FTP) sensor
circuit high voltage
FTP
sensor to ECM signal ground
circuit open circuit
F
TP sensor to ECM wiring (supply,
sense, signal, ground) short circuit
to each other
FTP
sensor to ECM sense circuit
short circuit to high voltage
F
TP sensor failure
F
or evaporative emissions pinpoint
tests,
REFER to Section 303
-1
3 Evaporative

Emiss
ions
.
P0460Fue

l level sense signal
performance
Fue
l level sensor
to instrument
cluster circuits in termittent short or
open circuit
F
uel level sensor failure
Instrument cluster
faul
t (incorrect
fuel level data)
F
or fuel level sensor
circuit tests,
REFER to Section 303
-04
Fuel
Charging and Con

trols
.
P0506Idl

e rpm lower than expected
Ai
r intake blockage
Acce

ssory drive overload
(defective/siezed component)
Thr
ottle valve stuck closed
Throttl

e assembly failure
Chec
k the air intake system.
REFER to Section 303
-1
2 Intake Air
Distribu

tion and Filtering
.
Check t
he accessory drive
components,
REFER to Section 303
-0
5 Accessory
Dr

ive
.
F
or throttle body information,
REFER to Section 303
-04
Fuel
Charging and Con

trols
.
P0507Idle rpm

higher than expected
Inta
ke air leak between MAF
sensor and throttle
Inta
ke air leak between throttle
and engine
Engine
breather leak
Cruis

e (speed) control vacuum
failure
Thr
ottle valve stuck open
Throttl

e assembly failure
Chec
k the air intake system.
REFER to Section 303
-1
2 Intake Air
Distribu

tion and Filtering
.
Chec
k the engine breather system,
REFER to Section 303
-08
Engine
Emissi

on Control
.
F
or cruise (speed) control information,


REFER to Section 310
-03
Speed
Control.
F
or throttle body information,
REFER to Section 303
-04
Fuel
Charging and Con

trols
.
P0560Vehicle voltage

malfunction
ECM battery
power supply open
circuit, high resistance
F
or ECM power supply circuit tests,
GO to Pinpoint Test AD.
.
P0566Cruise (speed) contr
ol
CANCEL
switch ON fault
Cru
ise (speed) control switches
internal steering wheel short circuit
to ground
For cru
ise (speed) control circuit tests,


REFER to Section 310
-03
Speed