evaporative canister purge valve JAGUAR X308 1998 2.G Workshop Manual

                    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)  

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

Engine Emission
Control - Exhaus
t Gas Recirculation (EGR) Valve
Remo
val and Installation
Remov
a
l
1.
Re
move the engine cover.
For additional informat ion, refer to Section 501
-05
Interior
Trim and Ornamen
t
ation
.

2. Disc
onnect the evaporative emission canister purge valve
electrical connector.

3. Detac
h and reposition the evaporative emission canister purge
valve.

4. NOTE : Cap the coolan
t hose
to minimize coolant loss.
Disconnect the coolant hose.
5. Disconnect the exhaust gas recirc ulation (EGR) valve electrical
connector.

5. Tigh
ten the EGR valve to throttle body retaining bolts.
Tigh

ten to 12 Nm.

6. Con
nect the EGR valve electrical connector.

7. NO
TE: Un-cap the coolant hose.
Connect the coolant hose.
8. Attach the evaporative emission canister purge valve.
Tigh
ten to 6 Nm.

9.
Connect
the evaporative emission canister purge valve
electrical connector.
10. Check and if necessary to p up the cooling system.
11. Install the engine cover.
For additional informat ion, refer to Section 501
-05
Interior
Trim and Ornament

ation
.

E
ngine Emission Control - Exhaust Ma
nifold to Exhaust Gas Recirculation
(EGR) Valve Tube
Re
moval and Installation
Remov

al
1.
R
emove the engine cover.
For additional informat ion, refer to Section 501
-0
5 Interior
Trim and Ornamen

tation
.

2. Di
sconnect the evaporative emission canister purge valve
electrical connector.

3. De
tach and reposition the evaporative emission canister purge
valve.

4. Di
sconnect the exhaust gas recirc
ulation (EGR) valve electrical
connector.
5. Remove the exhaust manifold to EGR valve tube retaining
bolts.
Remove an
d discard the exhaust manifold to EGR valve
tube gasket.

4.
Att
ach the evaporative emission canister purge valve.
1. Tighten to 6 Nm.

5. Conne
ct the evaporative emission canister purge valve
electrical connector.
6. Install the engine cover.
For additional informat ion, refer to Section 501
-0
5 Interior
Trim and Ornamen

tation
.

Evaporative E
missions - Evaporative Emissions
Description an
d Operation

To reduce the emission of fuel vapour, th e fuel tank is vented to atmosphere through activated charcoal adsorption canister
(s) which collects the fuel droplets. The ch arcoal is periodically purged of fuel when the EVAP Canister Purge Valve opens
the vapour line between the canister(s) and the air intake induct ion elbow. This action allows manifold depression to draw
air through the canister atmospheric vent, taking up the deposited fuel from the charcoal adsorber and burning the resulting
fuel vapour in the engine.
The EVAP Canister Purge Valve is controlled by the engine management system ECM. Purging is carried out in accordance
with the engine management fu eling strategy (see below).
The fuel tank vapour outlet is via a removeable flange assemb ly on the top surface of the tank. The vapour storage canister
or canisters are fitted on the underside of the vehicle below the rear seats.
There are three variants of the evaporativ e system. All systems use the charcoal adsorber storage canisters and purge valve
and operate as described above. The specific features of each system are described below. The evaporative systems are
designated as :
sin g
le canister system
ru
nn
ing loss system
ru
nn
ing loss with On-board Re-fueling Vapour Recovery (ORVR) system
EVAP Canister Purge Valve

Ite
m
Par
t
Number
De
scr
iption
1—EVAP canister purge v
alve
2—Valve s
olenoid connector
3—Vapour outlet to indu
ction elbow
4—Vapour
inlet from canister(s)
5—Vacuum contro
l pi
pe from induction elbow
6—Vacuum contro
l pi
pe to vapour pressure control va
lve - applicable to single canister systems only
7—Vacuum
control connection to EVAP valve

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.

Thi s
system uses a single charcoal canister with a pressure
control valve between the canister and the fuel tank vapour
outlet. A vacuum control pipe is connecte d from the engine intake induction elbow to the pressure control valve. The vapour
outlet from the fuel tank is taken via a safety rollover valve fitted to the re moveable flange at the top of the tank.
With the engine stopped, the pressure control valve is closed, maintaining a slight positive pre ssure in the tank : any further
increase in pressure causes the valve to open and release vapour to the canister.
When the engine is running, manifold depr ession (via the vacuum control pipe) holds the pressure control valve open. Air is
drawn into the tank to maintain atmospheric pressure as fuel is used and vapourised fuel is deposited in the charcoal
canister.
Canister purge operation is as described in Evaporative Emissions Control.
It e
m
Par
t
Number
De
scr
iption
1—Evaporative flan
ge assembly
2—Vapour outlet rol
lover valve
3—Tank vapour outlet pipe
4—Breather
pipe
5—Pressure control valve
6—Induct
ion vacuum control pipe
7—Charcoal can
i
ster
8—Canister vapour outlet pipe
9—EVAP canister purge v
a
lve
10—Vacuu
m
control sign
al from induction
11—EVAP ca
nister purge valve outlet
12—Canist
er vent
to atmosphere
Single Ca
nister System