speed JAGUAR X308 1998 2.G Workshop Manual

Di
sconnect the speed control switch
pack electrical connector, SW02.
1
Meas
ure the resistance between SW
02, pin 06 (BO) and GROUND.
2
Meas
ure the resistance between SW
02, pin 04 (SR) and GROUND.
3
Is either resi
stance
less than 10,000 ohms?
Yes REPAIR the short circuit. For addi tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
No GO to E2
.
E2
: CHECK THE SPEED CONTROL CASSE
TTE REEL FOR SHORT TO GROUND
M
easure the resistance between SW02, pin 06 (at the cassette reel side of the connector) and
GROUND.
1
M
easure the resistance between SW02, pin 04 (at the cassette reel side of the connector) and
GROUND.
2
Is either resi
stance
less than 10,000 ohms?
Yes REPAIR the short circuit. For addi tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
No GO to E3
.
E3
: CHECK THE SPEED CONTROL
ACCEL/SET+ SWITCH ACTION
Meas
ure the resistance between SW02,
pin 06 (BO) and SW02, pin 04 (SR).
1
Op
erate the cruise control
ACCEL/SET+ switch.
2
D
oes the resistance
vary by 430 ohms?
Yes Recheck DTCs. No short found. Po ssible intermittent fault. CLEAR the DTC. TEST the system for
normal operation.
No INSTALL a new speed control switchpack. CLEAR the DTC. TEST the system for normal operation.
P
INPOINT TEST F : DTC P1571;
BRAKE SWITCH MALFUNCTION
WAR
NING: Where tests involve the removal of the steering
wheel, and/or disconnection of air bag connectors, the
procedure for disarming air bags must be followed,
REFER to: Air Bag Supplemental Re straint System (SRS)

(501-20B Supplemental Restra
int System, Description and
Operation).
TE
ST
CONDITIONS
D
ETAILS/RESULTS/ACTIONS
F1: CHECK THE BRAKE

SWITCH TO
ECM CIRCUIT FOR HIGH RESISTANCE
Di
sconnect the battery negative terminal.
1
Di

sconnect the brake switch electrical connector, AC24.
2
D

isconnect the ECM electrical connector, EM10.
3
Meas

ure the resistance between AC24,
pin 01 (US) and EM10, pin 10 (US).
4
Is th
e resistance greater than 5 ohms?
Yes REPAIR the high resistance circui t. For additional information, refer to the wiring diagrams. CLEAR
the DTC. TEST the system for normal operation.
No GO to F2
.
F2: CHECK THE BRAKE
SWITCH TO ECM
CIRCUIT FOR SHORT TO HIGH VOLTAGE
R
econnect the battery negative terminal.
1
Turn the ignition swi

tch to the ON
position.
2
M
easure the voltage between AC24, pin 01 (US) and GROUND.
3
Is th

e voltage greater than 3 volts?
Yes REPAIR the short circuit. For addi tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
No GO to F3
.
F3: CHECK THE BRAKE
SWITCH TO
ECM CIRCUIT FOR SHORT TO GROUND
Turn the ignition swi
tch to the OFF
position.
1
Meas
ure the resistance between AC24, pin 01 (US) and GROUND.
2

Is t
he resistance less than 10,000 ohms?
Yes REPAIR the short circuit. For addi tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
No GO to F4
.
F4: CHECK THE BRAKE SWITCH IGNITION SWIT
C
HED GROUND CIRCUIT FOR HIGH RESISTANCE
Di
sc
onnect the battery negative terminal.
1
Di
sc
onnect the brake switch electrical connector, AC24.
2
Di
sc
onnect the ignition switch electrical connector, FC04.
3
Measure t

he resistance between AC24,
pin 04 (WO) and FC04, pin 03 (WO).
4
Is the res
istance greater than 5 ohms?
Yes REPAIR the high resistance circui t. For additional information, refer to the wiring diagrams. CLEAR
the DTC. TEST the system for normal operation.
No GO to F5
.
F5: CHECK THE BRAKE SWITCH O
PERATION
Me
asure
the resistance between AC24, pins 01 and 04.
1
O
p
erate the brake pedal up and down.
2
Doe
s
the resistance switch between open circuit and continuity as the pedal is operated?
Yes GO to F6
.
No
INST
ALL a new brake switch. CLEAR the DTC.
TEST the system for normal operation.
F6: CHECK THE BRAKE CANCEL
SWITCH
TO ECM CIRCUIT FOR HIGH RESISTANCE
Disc
onnect the brake switch electrical connector, AC24.
1
D
i
sconnect the ECM electrical connector, EM10.
2
Me
asure
the resistance between AC24, pin 02 (PG) and EM10, pin 11 (PG).
3
Is th
e res
istance greater than 5 ohms?
Yes REPAIR the high resistance circui t. For additional information, refer to the wiring diagrams. CLEAR
the DTC. TEST the system for normal operation.
No GO to F7
.
F7: CHECK THE BRAKE CANCEL
SWITCH TO
ECM CIRCUIT FOR SHORT TO HIGH VOLTAGE
Re
connect the battery negative terminal.
1
Turn the ignition swi
t
ch to the ON
position.
2
Me
asure the voltage between AC24, pin 02 (PG) and GROUND.
3
Is th
e volt
age greater than 3 volts?
Yes REPAIR the short circuit. For addi tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
No GO to F8
.
F8: CHECK THE BRAKE CANCEL
SWITCH
TO ECM CIRCUIT FO R SHORT TO GROUND
Turn the ignition swit
ch to the OFF
position.
1
Measure t
he resistance between AC24, pin 02 (PG) and GROUND.
2
Is
t
he resistance less than 10,000 ohms?
Yes REPAIR the short circuit. For addi tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
No GO to F9
.
F9: CHECK THE BRAKE CANCEL
SWITCH
TO CRUISE CONTROL SWITCH TO ECM CIRCUIT FOR HIGH RESISTANCE
Disc
onnect the battery negative terminal.
1
Di
sc
onnect the brake switch electrical connector, AC24.
2
D
i
sconnect the ECM electrical connector, EM11.
3
Di
sc
onnect the speed control switch electrical connector, FC63.
4
Me
asure
the resistance between AC24, pin 03 (WU) and EM11, pin 04 (WU).
5
Is th
e res
istance greater than 5 ohms?
Yes

Climate Control System - General Informatio
n - Climate Control System
D
iagn
osis and Testing
I
n
troduction
It is very i
m
portant to positive
ly identify the area of concern before starting a rectification procedure. A little time spent with
your customer to identify the conditions under which a pr oblem occurs will be beneficial. See below for example:
Sym
ptom Chart
Re
lev
ant criteria are: Weather conditions,
ambient temperature, intermittent or cont inuous fault, airflow fault, temperature
control fault, distribution fault and air inlet problem.
Functio n
al Check
This
s
imple 'first line check' will allo
w you to ascertain whether the system is operating within its design parameters, withou t
recourse to PDU.
1. 1. With the engine at normal running temperature.
2. 2. Presss AUTO to display selected temperature and illuminate AUTO and A/C state lamps.
3. 3. Rotate FAN to increase or decrease lowe r speed, verify bar graph representation.
4. 4. Select A/C to toggle on or off. (T he compressor may be inhibited by the ECM should either the engine
temperature NOT be normal or the ambient be < 2° C).
5. 5. Select RECIRC , state lamp should be lit and the recirculation flaps open.
6. 6. Select distribution butt ons in turn, verify correct air distribution and relevant state lamp.
7. 7. Select DEFROST , check max fans and air to the windshield.
8. 8. Cycle TEMPERATURE to ' HI ' and ' LO ' to verify demanded variations and display operation. Note that extremes
will provide max heat or cold independent of in-car temperature.
9. 9. Select EXT to toggle between am bient and control temperatures.
10. 10. Select F (where fitted) and R - noting exterior mirror; verify timer and operation (glass may be warm to the
touch)
11. 11. Initiate system 'Self Test' to display stored faul ts should any of the above not perform as stated.
Sy
stem Symptoms
There
are five
basic symptoms associated
with air conditioning fault diagnosis.
The following conditions are not in order of priority.
Sy m
ptom
Possib
l
e Sources
Acti
o
n
N
o defrostN o
airflow to windshield
*
Check blower s and flaps
*
N o functi
on in defrost mode
*
Check A/CCM
*
Mo de s
election not available
*
Chec k
control panel communication
*
Ai rfl
ow OK but no heat
*
Check water pu
mp and valve
*

Symp
tom #5
Sy
m
ptom #5


Low r
e
frigerant charge
*
Check f or 'hissi
ng' at expansion
valve; may be witnessed by low
HIGH side pressure. Recover / recharge
*
Moi
s
ture or air in the system
*
Chec k syst
em pressures
*
Heat er ci
rcuit air-lock
*
R e
fer section 303-03 for fill / bleed procedure
*
Suct ion
pipe touching bank 1 (A)
cylinder head (rubber isolator
missing)
*
Check the pi
pe cluster for correct fitti
ng
*
• NOTE: Electrical faults may be more rapidly traced using PDU
Sym
ptom
Possib
l
e Sources
Acti
o
n
Insuffi
ci
ent
heating
Coo l
ant flow valve stuck 'closed'
Coolant flow valve stuck 'open' allowing recirculation of
coolant at engine idle
*
*
Re
new v
alve
*
Motorized in-car aspirator sei zed
*R e
new aspirator
*
Coo l
air bypass damper stuck open

*
Re new,
check fault code #43

*
B l
ocked air inlet / pollen filter
*
Chec k / cl
ean / renew
*
B l
ower speed low
*
Check performance range
*
Low cool ant
level
*
Adjust as req u
ired (verify and correct
reason for loss)
*
Engine
t
hermostat faulty
*
Check engine r u
nning temperature
*
Heater water pump seized
*Chec k op
eration
*
Heater ma trix
blocked
*
Re new m
atrix
*
Heater circui t
air-lock
*
R e
fer section 303-03 for fill / bleed
procedure
*

Sym
p
tom #4
Sym
ptom #4
Sy
m
ptom
Possib
l
e Sources
Acti
o
n
No
i
sy
system
Loose or damaged compressor drive
belt
*Adjust or r
e
new
*
Loose compressor mountings
*Check f o
r damage, tighten to specification if OK
*
Compressor oil level l
ow
*
Look for evidence of l
eakag
e and rectify as required
*
Compressor internal dama ge
*Check f o
r debris, renew compressor and receiver drier
*
B l
ower motor noise
*
Re new m
otor (assuming no fan interference)
*
Excessive refrige rant charge
*Check f o
r vibration or 'thumping'
in high pressure line; may be
witnessed by high pressure on both HIGH and LOW sides.
Recover / recharge
*

Climate Co
ntrol System - General
Information - Refrigerant Adding
Gen
eral Procedures
CAUTION: If oil was drawn out during the recovery process, the correct amount may be added directly from the
recovery, recycle and recharge station (if so equipped) prior to the charging process. It must be stressed that the need to
protect compressor oil from moisture is vital, observe the pr ocedures in HANDLING LUBRICATING OIL and those concerning
excessive engine speed.


1. In order that the
air conditioning system may operate
efficiently it must contain a full refrigerant charge. The
indications of some system defects, and the results of certain
tests, will show that a low charge is the most probable cause of
the fault. In such cases the ch arge should be recovered from
the system, the weight noted, and the correct amount added.
Should refrigerant be added in liquid form, the engine speed
must not exceed 2000 rpm for a period of two minutes after
first running the compressor. If the engine speed is excessive,
compressor damage may occur du e to the lubricating oil and
the liquid refrigerant being initia lly forced around the system as
a 'slug', thus taking oil away from the compressor. These
marginal lubrication conditions in the compressor will cease as
the refrigerant becomes gaseous.
Never attempt to estimate the amount of refrigerant in a
system. Always recover and rech arge with the correct charge
weight; this is the only accurate method.

Parts List
The heater circuit 'scavenges' coolant from the engine cooling system by mean s of an electric water pump. The water pump
has a protection circuit to inhibit operation when the coolant temperature is <16°C; this is to prevent possible damage to
the impeller due to the presence of coolant borne ice particles. Coolant is drawn from the en gine system through the water
valve inlet port into the heater matrix. The coolant passes thro ugh the bottom section of the heater matrix from left to right
filling the end tank of the matrix before returning through the top half of the ma trix and through the outlet ports of the
water valve and back into the engine cooling system.
Non return valves are located in the heat er bypass hose and the hose between the water pump and valve. These valves are
required to prevent coolant flowing in th e wrong direction at low engine speeds and restrict convected flow through the
heater after the engine is switched off.
When the exterior ambient temperature is > 0°C the refrigerat ion system automatically operates cooling and dehumidifying
incoming air before it is re -heated by the heater matrix.
Water Valve Assembly
Location
The water valve assembly is located above the water pump, in the engine compartmen t and is secured to the firewall by a
bracket. The valve operates by means of an electrical solenoid which oscillates the valve stem between the inlet and outlet
ports.
When in automatic mode, the water valve duty cycle is influenced by the following inputs to the A/CCM:
Outlet air temperature 'Air off' heater matrix temperature External ambient Coolant temperature
ItemPart NumberDescription
1—Assembly pump - water
2—Hose - from header tank
3—Hose / connector - return to engine
4—Hose - heater feed to matrix
5—Valve - non return (by-pass)
6—Hose / connector - feed from engine
7—Hose - heater return from matrix
8—Assembly valve - water
9—Valve - non return

Engine speed (valve closed with the engine not running) Demand (set) temperature In-car temperature sensor Solar sensor
Re-heating of the refrigerated air is contro lled by the time that the water valve is open (i.e. not energised) over a six secon d
interval. The duty cycle of the water valve, the time open / time closed, is controlled by the A/CCM.
Maximum heating demand will cause the water valve to be fu lly open (not energised) to allow maximum coolant flow
through the heater matrix.
At Maximum cooling, the water va lve will be fully closed (energised) to prevent hot (engine temperature) coolant entering
the heater circuit; the pump however will continue to circulate coolant through both the heater matrix and water valve
bypass.
The water valve defaults open when the ignition is OFF.
Under engine stall conditions, when ignition is ON, the water valve will be open.
Water Pump Assembly
Located in the same area as the water valve, the water pump continually circulates coolant through the heater matrix
except when the conditions below apply:
The engine coolant is below 16°C. The ignition is OFF. Under engine stall conditions, when ignition is ON. Control panel OFF
Non return valves
The heater bypass hose has a non-return valve, located between the engine feed and return hoses. The valve prevents the
water pump from recirculating coolant fro m the heater at low engine speeds.
The flow indicator arrow embossed on the valve bo dy MUST point towards the coolant header tank.
CAUTION: Coolant flow will be compromi sed if either valve is fitted incorrectly. Observe the correct direction.
A second non-return valve is located betw een the water pump and water valve. This valve prevents hot coolant from flowing
into the heater with the engine switched off. The flow indicator arrow MUST point towards the water pump.
Heater feed and return hoses
The heater feed and return hoses are connected to the engine feed and return hoses by 'Quick-Fit' connection unions. The
feed hose has a Norma R20 connector and the return hose a Norma push and seal connector. The coolant system bleed
joints have Cobra clamps. All remaining hose connections have spring band hose clamps.
The engine feed hose is connected to the engine bypass hous ing and the engine return hose is connected to the engine
water pump.
Clamp Identification

Air Conditioning - Air Conditioning
Description and Operation
Introduction

Parts List
The climate control system features fully automatic control of temperature, blower speed (airflow) and air distribution to
maintain optimum comfort under most driving conditions.
Manual controls are provided to allow the operator to over-ride automatic operation.
System Features
ItemPart NumberDescription
1—Fascia panel with integral ducting
2—Heater / cooler assembly
3—A/CCM
4—Blower LH and RH
5—Plenum
6—Control panel
7—Solar sensor
8—Assembly valve - water
9—Assembly pump - water
10—Temperature sensor - external
11—Compressor
12—Pressure switch - 4 level
13—Motorized in-car aspirator (LHD shown)
14—Receiver drier
15—Condenser

Twin blower assemblies Center mounted evaporator, heater and air distribution unit Electric solenoid water valve controlled heating Electric water pump assembly Servo motor driven air distribution flaps Dedicated side glass defrost / demist vents External temperature sensor Motorised in-car aspirator Solar sensor
Electronic Control Panel
Liquid Crystal Display (LCD) Digital temperature display Manual fan speed level External temperature display Celsius / Fahrenheit selection Heated windshield switch (where fitted) Heated backlight switch Defrost switch Manual airflow distribution overrides (4) Access to self diagnostic system and error codes
Sensors
External ambient temperature sensor Motorized in-car aspirator Heater matrix temperature sensor Evaporator temperature sensor Solar sensor
These sensors feedback information to the Air Conditioning Control Module (A/CCM) which automatically adjusts air
temperature, airflow volume and distributi on from the air conditioning unit to maintain a stable passenger compartment
average temperature under changing weather conditions.
Major Components

Condenser:
Multi-pass fin-over-tube type, mounted in front of the engine cooling pack and directly to the radiator.
Pressure (Bitron) switch:
Located in the discharge pipe. Provides a signal, via the A/CCM, to th e ECM, to disengage the compressor clut ch should the refrigerant pressure be
< 2 bar or > 30 bar.
Provides a hard-wired signal to the ECM, to switch the cool ing fans to HIGH speed at 22 bar rising pressure and to
LOW speed at 17,5 bar falling pressure.
Provides a hard-wired signal to the ECM, to switch the radiator cooling fans to LOW speed at 12 bar rising pressure
and to switch the fans OFF at 8 bar falling pressure.
Expansion Valve

Parts List
The expansion valve is located inside the heater / air conditioning unit and comprises of a diaphragm, connected by a
capillary tube to a temperat ure sensing bulb, which regulates the valve according to temperature variations at the
evaporator outlet pipe. This component is NOT serviceable. See 'Refrigeration Cycle'
Air Conditioning (Heater / Cooler) Unit
ItemPart NumberDescription
1—Valve body
2—Pressure spring
3—Diaphragm
4—Capillary tube
5—Temperature sensing bulb
6—Valve inlet
7—Valve outlet
8—Equalizer pipe