1998 JAGUAR X308 speed control

Is the res
istance greater than 5 ohms?
Yes REPAIR the circuit. For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST
the system for normal operation.
No GO to C10
.
C10: CHECK T H
E ECM TO CASSETTE REEL
CIRCUIT FOR CONTINUITY (CIRCUIT 2)
Measure t
he resistance between EM11,
pin 05 (SG) and SW01, pin 03 (SG).
1
Is the res
istance greater than 5 ohms?
Yes REPAIR the circuit. For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST
the system for normal operation.
No Contact dealer technical support for advice on possible ECM failure.
PI
NPOINT TEST D : DTC P0
569; SPEED CONTROL DECEL/SET- SWITCH ON FAULT
WARN
ING: 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)
(50
1-20B Supplemental Restra
int System, Description and
Operation).
TE S
T
CONDITIONS
D E
TAILS/RESULTS/ACTIONS
D1: CHECK

THE SPEED CONTROL SWITCHPACK IN
TERNAL CIRCUITS FOR SHORT TO GROUND
Disc
onnect the speed control switch
pack electrical connector, SW02.
1
Measure t
he resistance between SW
02, pin 06 (BO) and GROUND.
2
Measure t
he resistance between SW
02, pin 04 (SR) and GROUND.
3
Is either resistance le
ss 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 D2
.
D2: CHECK
THE SPEED CONTROL CASSE
TTE REEL FOR SHORT TO GROUND
Me
asure the resistance between SW02, pin 06 (at the cassette reel side of the connector) and
GROUND.
1
M e
asure the resistance between SW02, pin 04 (at the cassette reel side of the connector) and
GROUND.
2
Is either resi stance le
ss 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 D3
.
D3: CHECK
THE SPEED CONTROL DECEL/SET- SWITCH ACTION
Meas
ure t
he resistance between SW02,
pin 06 (BO) and SW02, pin 04 (SR).
1
Operate
the speed control
DECEL/SET- switch.
2
Do
es the resistance
vary by 680 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.
PINPOI
NT TEST E : DTC P0570; SPEED CONTROL "ACCEL/SET+" SWITCH "ON" FAULT
WAR
N
ING: 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)
(50
1-20B Supplemental Restra
int System, Description and
Operation).
TE S
T
CONDITIONS
D E
TAILS/RESULTS/ACTIONS
E1
: CHECK THE SPEED CONTROL
SWITCHPACK IN
TERNAL CIRCUITS FOR SHORT TO GROUND

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
*

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

Control Components - Control Components
Description and Operation
System Controls
The climate control system is controlled by : 1. 1. Manual input from the operator, via the center console located control panel.
2. 2. Automatically by means of the A/CCM.
Output is based upon input from the following devices:
Motorized In-car aspirator External air temperature sensor Coolant temperature sensor Heater 'air-off' (the temperature of the air leaving the matrix fins) temperature sensor Evaporator 'air-off' (the temperature of the air leaving the evaporator fins) temperature sensor Solar sensor Left hand blower recirculation / fresh air flap potentiometer Right hand blower recirculation / fresh air flap potentiometer Upper air distribution box (ADB) center and side face flap servomotor potentiometer ADB defrost flap servomotor potentiometer Air conditioning unit Foot flap servomotor potentiometer Air conditioning unit Cool Air Bypass flap servomotor potentiometer Thumbwheel controls on the facia vent assemblies which provide manu al adjustment of the airflow volume. Road and engine speed signals input to the A/CCM
Climate Control Panel
Communication between the control panel and the A/CCM is via a serial data communications link.

Switching the Climate Control system ON
The climate control system can be switched ON by pressing one of the following :
Ref #1 On / Off (resumes the system on in the previous settings).
Ref #10 A / C (resumes the system on in the previous settings).
Ref #11 AUTO (resumes the system on at the previous temperature setting).