1998 JAGUAR X308 oxygen

                    Superchar
ger
 Outlet  Pipe (18.50.16)  
                     Supercharger  Outlet  Pipe Gasket  (18.50.17)  
                     Throttle Body  Elbow  (19.70.28)  
                     Throttle Body  Elbow  Gasket  (19.70.29)  
 
             303‐13:  Evaporative  Emissions  
                 Diagnosis  and  Testing  
                     Evaporative  Emissions 
                                       
Preliminary
 Inspection
 
                     Diagnostic
 Drive  Cycles  
                     Diagnostic
 Trouble  Code  (DTC)  index/Symptom  Chart  
                     Pinpoint
 Tests  
                 Removal
 and  Installation  
                     Evaporative 
Emission Canister  (17.15.13)  
                     Evaporative 
Emission Canister  Purge  Valve (17.15.30)  
                     Fuel
 Tank  Press
ure Sensor  (19.55.31)  
                     Fuel
 Vapor  Vent  Valve  Housing  (19.55.24)  
                     Fuel
 Vapor  Vent  Valve  Housing  Seal  (19.55.25)  
 
             303
‐14:  Electronic  Engine  Controls  
                 Description
 and
 
                                      Diagnosis
 and  Testing  
                     Electronic
 Engine  Con
trols  
                     Inspection
 and  Verification  
                     Driver
 Information  Chart  
                     Default 
mode Definitions  
                     Diagnostic
 Trouble  Code  (DTC)  Index  
                     Pinpoint
 Tests  
                 Removal
 and  Installation  
                     Catalyst 
Monitor  Sensor LH  (18.30.81)  
                     Catalyst 
Monitor  Sensor RH  (18.30.80)  
                     Heated Oxygen  Sensor  (HO2S)  LH  (18.30.79)  
                    
Heated Oxygen  Sensor  (HO2S)  RH  (18.30.78)  
                    
                    
Camshaft  
Position  
Sen s
or
 
ECM  
Position  
Sensor  
Crankshaft
Removal
Engine  
Coolant Temperature
Sensor 
Operation
Intake  Air  Temperature  (IAT)  Sensor  (18.
30.52)  

Electrically Programmable
R
ead-Only memory
EPROM
Ele
c
tronic Secondary Air
Injection
EAIRA p
ump-driven system for providing seco
ndary air using an electric air pump
Engine C
ontrol Module
ECM
End of dashEODR
e
ferring to a vehicle fascia, eg EOD air vent
Engine
C
oolant Level
ECL
Engine
C
oolant
Temperature
ECT
ECT Sen s
or
ECTSTherm
i
stor which provides engine coolant temperature signal to the ECM to
trigger enrichment circuits which increase injector 'on' time for cold start and
warm-up
Engine s
peed
RP
M
Environ m
ental Protection
Agency
EPA
Evaporative EmissionEVAPSy stem designed to prevent fu
el vapor from escaping into the atmosphere.
Typically includes a charcoal filled canister to absorb fuel vapor
Evaporative Emission
Control ValveEVAPP
Exhaust G
as Recirculation
EGRSys
t
em which reduces NOx emissions by adding exhaust gases to the
incoming fuel/air charge
Exhaus t G
as Recirculation

Solenoid Vacuum Valve
EGRS
Exhaus t G
as Recirculation

Temperature Sensor
EGRT Sen s
or
Exhaus
t G
as Recirculation

Valve
EGRV
F
F a
n Control
FCEngine

cooling fan control
F
e
deral Motor Vehicle
Safety Standard (US)
FMV S
S
Fi
gur
e
Fi
g.Illustrati
on reference
Flash
E
lectrically Erasable

Programmable Read-Only
Memory
FEE PR
OM
Flash
E
rasable
Programmable Read-Only
Memory
FEP R
OM
Flywhee
l
Sensor
CKFSSens
or moun
ted so as to be
triggered by each flywheel ring gear tooth to give
an engine speed signal
Fue l
Injectors
FISol
e
noid operated devices that spray a metered quantity of fuel into the inlet
ports
F u
el Pressure Regulator
Control
FP RCControls fuel pressure regu l
ator; used primarily to
give extra fuel at cold
start-up
Fue l
Pump
FP
Fue
l
Pump Monitor
FP
MMonitors operation of fuel pump
Fue l
Pump Relay
FP
R
Fu
el rich/lean
Q
u
alitative evaluation
of air/fuel ratio based on a ratio known as
stoichiometry, or 14.7:1 (Lambda)
F u
ll Scale Deflection
FSDTh
e
maximum indication point on
an analogue meter or gauge
G
Gene
rator
GENRot
a
ting machine which converts mechanical energy into electrical energy
G
r
amme centimeter
gcm
Gramm
e
(force)
gf
Gramm
e
(mass)
g
GroundGNDEle
c
trical conductor used
as a common return for an electrical circuit or
circuits, and with a relative zero potential
H
Hard f a
ult
A
fau
lt currently present in the system
HeadlampHL
Heat
ed Oxygen
Sensor
HO2SElectrically
h
eated oxygen sensor which induces fueling corrections
Hertz (frequency)HzFrequ
e
ncy, one cycle per second
High
Moun
ted Stoplamp
HMSL

Meter (measurement)m
Me
tric (screw thread, e.g.

M8)
M
MicrofaradMFDUni t
of electrical capacitance, one millionth of a farad
Mi
ll
imeter
mm
Mi
ll
imeter of mercury
mm
Hg
Mill
isecond
ms
Min
i
mum
mi
n.
Min u
te
minut
e
Model YearMY
ModuleMSelf
contained group of electrical/electronic components which is designed as
a single replaceable unit
Modulating signalMDA sh
ift process signal to the TCM on SC vehicles
Motorized In
-Car
AspiratorMIAD e
vice which constantly samples cabi
n temperature by passing air over a
sensor, and communicates with the A/ CCM to modify A/C system performance
to suit
Mult i Prot
ocol Adaptor
MPAAn i
n
terpreter for the various data
languages present on a vehicle
N
Nati
onal Institute of
Occupational Safety and
Health (US)
NIO S
H
Ne
wto
n
NSI unit of force. 1
N = 0.224
8 pounds force
Ne
wto
n meter
NmSI unit of torque. Must not be
co
nfused with nm (nanometer)
Ni
tr
ous Oxide
NO
xCompounds of nit rogen and oxygen fo rmed at high temperatures. Major
sourc
e of exhaust-gas air pollution
No
n
-Volatile Random
Access Memory
NVR A
M
R
A
M which retains memory even
if power supply is interrupted
Normal
ly aspirated
F
u
eling system using intake air at atmo
spheric pressure; not supercharged or
turbocharged
N ormal
ly Closed
NC
N
o
rmally Open
NO
No
r
th American
Specification
NASVehicles f or sal
e in the USA and Canadian markets
Nu
mbe
r
No
.
O
Oc
cupational Safety and
Health Administration
(US)
OS H
A
O
n
-Board Diagnostic
OB
DA system that moni
tors some or all co
mputer input and output control signals.
Signal(s) outside the pre-de termined limits imply a fault in the system or a
related system
O n
-Board Refueling
Vapor Recovery
OR V
R
O
riginal
Equipment
Manufacturer
OE M
Outp
ut
O/
PAn electrical o u
tput signal from a controlling device
Ou
ts
ide diameter
o.
d
ia
O
xides of
nitrogen
NO
x
Oxygen senso
r
O2
SA s
ensor which detects oxygen content in the exhaust gases
P
Parameter Identifi
erPIDAn in
dex number referring to a parame
ter within a module without knowledge
of its storage location
Park N e
utral Position
PN
P
Park N e
utral Position
Switch
PN PSIndic
ates the selected non-drive modes of the (automatic) transmission
Part numberpart no.
Portable Diag
nostic Un
it
PD
UCompre hen
sive electrical diagnosis system specific to Jaguar vehicles
Posi
ti
on
po
s'n
Power As si
sted Steering
PASHydraul
i
c pump-assisted steering system
Power Steer
i
ng Pressure
PSP
Programmable Elect
r
onic
Control Units System
PECU SProcess whereb y
a common ECM is progra
mmed on the production line to suit
the market requirements of a particular vehicle
Programmable Read-O
nly

PROMRO
M with some provision for setting
the stored data after manufacture

2—Ignition ampl
ifier failure
3—Crankin

g
4—Camshaft position


5—Mass ai

r flow
6—Inta

ke air temperature
7—Coo

lant temperature
8—Exhaus

t gas oxygen content
9—Knock

sensor

10—Power supply
11—Cl
imate control compressor
12—Cli

mate control system pressure
13—Traction contr

ol
14—Park / neutral

switch
15—Throttle pedal demand


16—Thro

ttle position
17—Securi

ty mode



ECM In
puts
It

em
Par
t Number
De
scription
1—Engine

speed

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

Thi
s sensor uses a piezo-electric sensing element to detect kn
ock which may occur under acceleration at critical conditions.
Should detonation be present the ECM will retard ignition timing of individual cylinders.
Exhaust G
as Recirculation
The EGR
valve (where fitted) reduces NOx
emissions by recirculating a portion of the exhaust gases back into the inlet
manifold.
Heated Oxyg
en Sensors
The h
eated oxygen sensors, one per bank, are situated upstream of the catalysts. Integral
to the sensors are heaters
(under ECM control) which allow the sensor s to reach their operating temperature as soon as possible after engine start. A
comparison between the level of oxygen in the exhaust gas to that in the atmosphere produces an output signal. This signal
is used by the engine closed loop fuel strategy to make fuelling corrections and so control overall emission levels.
Oxygen Sensors

Thes
e sensors, one per bank, are situated downstream of the
catalyst. The comparison of upstream and downstream signals
allows determination of cata lyst conversion efficiency.




Knock Sensor

36. Disconnect the engine oi l pressure transmitter.
37. Remove the filler cap from the power steering reservoir.

38. Disconnect the hoses from the power steering pump.
Position a drain tray under the pump.
1. Release the high pressure hose union nut and drain the fluid.
2. Discard the O-ring seal an d fit blanking plugs to the
pipe and union.
3. Release the feed hose from the pump and fit blanking
plugs to the pipe and union.
Discard the fluid.

39. Release the Oxygen sensor multi-plugs from the mounting
bracket and disconnect the plugs.
40. Remove the four nuts, each side, which secure the downpipe
catalytic converters to the exhaust manifold.

The E
VAP canister purge valve controls th
e flow rate of fuel vapour drawn into the engine during the canister purge
operation. The valve is opened by a vacu um feed from the induction elbow : the vacu um feed is controlled by the integral
valve solenoid and is applied when the so lenoid is energised. The solenoid is pulsed on (energised) and off by a fixed
frequency (100Hz) variable pulse width control signal (pulse width modulation). By varying the pulse on to off time, the
ECM controls the duty cycle of the valve (time that the valve is open to time closed) and thus the vapour flow rate to the
engine.
With no ECM signal applied to the va lve solenoid, the valve remains closed.
Can
ister Purge Operation
The
following pre-conditions are ne
cessary for purging to commence :
aft
er battery disconnection/reconnection, engine
management adaptations must be re-instated.
engine has run for
at least 8 seconds.
engi

ne coolant temperature is not less than 70 °C.
engine

not running in the fuel
cut off condition (eg overrun).
t
he adaptive fuel correction
function has not registered a rich or lean failure
t
he evaporative emission leak test has not failed
no faults have been diagnosted in th
e rel
evant sensor and valve circuits -
Air Flow Meter (AFM), Engine Coolant
Temperature sensor, Evaporativ e Canister Purge valve and Canister Close Valve (CCV).
If these conditions have been satisfied, purging is started. If any failures are registered, purging is inhibited.
The canister(s) is purged during each driv e cycle at various rates in accordance with the prevailing engine conditions. The
engine management software st ores a map of engine speed (RPM) against engine load (grams of air inducted / rev). For
any given engine speed and load, a vapour purge rate is assigned (purge rate increases with engine speed and load).
The preset purge rates are base d on the assumption of a vapour concentratio n of 100%. The actual amount of vapour is
measured by the closed loop fueling system : the input of evaporative fuel into the engine causes the outputs from the
upstream oxygen sensors to change, the am ount of change providing a measure of the vapour concentration. This feedback
causes the original purge rate to be adju sted and also reduces the amount of fuel input via the injectors to maintain the
correct air to fuel ratio.
Engine speed/load mapping and the corresp onding purge rates are different for single canister, running loss and ORVR
evaporative systems.