cooling system JAGUAR X308 1998 2.G Manual Online

Parts List
Air temperature from the centre (and EOD) vents is slightly cooler than the foot outlets; however this temperature cannot
be varied independently.
The EOD vents, not shown, feature similar controls.
Automatic Operation
Initial setting
Should a new A/CCM be fitted, it will 'power-up' in the OFF mode; switching ON will result in the following settings:
After initial start up the system operating conditions will be st ored in the A/CCM to the conditions which prevailed prior to
ignition OFF.
Maximum Heating / Cooling
Maximum Heating (temperature setting HI)
ItemPart NumberDescription
1—Airflow control
2—Air direction control
FeatureStatus
Setting temperature24°C or 75°F
LH and RH blower assembly recirculation / fresh flapFresh mode
Control modeAutomatic 'AUTO' displayed
BlowerAuto
Compressor outputA/C ON
Heated windshield and mirrorsOFF
Water valveAuto temperature control
ItemControlOverride Allowed
Water valveFully open (not energised)-
BlowerMaximumYes
Fresh / recircFreshYes
Air distributionFeet (state lamp OFF)Yes
A/C systemOFFYes
Cool air by-passFully closed-

Maximum Cooling (temperature setting LO)
Air Conditioning Control Module (A/CCM)
Location

The A/CCM is located on the right hand side of the air conditioning unit and controls all system functions.
The temperature within the passenger compartment is continually compared with the temperature selected on the control
panel LCD. The A/CCM receives data input signals and compares these with signal s from the system temperature sensors
and feedback devices. Based on this information the A/CCM adjusts the air outlet temperatur e, airflow and distribution from
the air conditioning system in to the passenger compartment.
Identification
ItemControlOverride Allowed
Water valveFully closed (energised)-
BlowerMaximumYes
Fresh / recircRecirculationYes
Air distributionFace (state lamp OFF)Yes
A/C systemONYes
Cool air by-passFully open-

The solar sensor is mounted on the top surface of the fascia between the defrost outlets.
The sensor is a photo-diode which is calibr ated to measure direct sunlight. It provides an output signal to the A/CCM which
automatically reduces air temperature an d increases fan speed (airflow volume) to compensate for solar heating.
Evaporator Sensor

This thermistor device changes electrical resistance as a result of temperature variations.
The sensor is positioned next to the evaporator fins and measures air temper ature after it has passed through the
evaporator. The sensor inputs a signal to the A/CCM which controls the compress or (see table) when the refrigeration
system is operating.
The sensor's connector is located on the LH side of the air conditioning unit, in front of the main power connector.
The A/CCM disengages the compressor clutch when the temperature of the air off the evaporator is 2° C or less. This is to
prevent the moisture which may collect between the cooling fins of the evaporator from freezing and thus restricting airflow.

Heater Matrix Temperature Sensor
Evaporator Temperature SignalCompressor State
3°CON - clutch engaged
2°COFF - clutch disengaged

other sensors. This feature prevents the effects of sudden changes in air outlet temperatures due to factors such as:
Recirculating air from the engine cooling pack at low vehicle speeds Sudden changes in ambient temperature The effects of water splash
Motorised In-car Aspirator.

An intake grille (mounted on the fascia , outboard of the steering column and below the EOD vent) houses the aspirator
thermister. The remotely mounted motor / fan assembly draws ca bin air through the grille and thus over the thermistor; a
flexible hose connects both components.
The electrical resistance of the thermistor changes in response to variations in air temperatur e, this change being converted
into an electrical signal. The A/CCM uses this signal to adjust the temperature, airflow and air distribution from the air
conditioning unit.
Coolant Temperature Signal.
This signal is supplied to the A/CCM from the instrument cluster, the input being required to:
Provide blower inhibit control , to avoid the system in heat ing mode delivering cold air when the coolant temperature is below 35°C unless DEFROST is selected. To progressively increase the fan speed up to maximum blower speed during warm up control. To assist in the control of the outlet temperature. To avoid possible pump or valve damage ca used by ice particles in the coolant.
Compressor ON Signal.
This signal monitors the compressor relay to confirm the compressor operating state and so provide relevant fault
information.
Servo Motor Control.
Flap position, which directs the flow of air through the system, is controlled by servo motors; these may be driven in either
a clockwise or anti-clockwise direction by signals from the A/ CCM. Motor, thus flap position, is monitored via a feedback
potentiometer which is situated within the motor housing.
Servo motors control the following flaps:

sliding roof finisher and clips. Carpet covered trims line the trunk and are secured by fir tree fasteners to the sides and fro nt inner panel.
Rear View Mirrors
The.interior rear view mirror is an electrochromic unit that automatically da rkens to prevent glare from following vehicle
lights. This automatic function is selected by pressing the switch at the bottom of the mirror. Pressing the switch again
cancels this function. An LED then illuminates when automatic dipping is operative. The light sensing unit for the Night
Sentinel automatic lamp operating system is also incorporated in the mirror casing.
The door mirrors are cheater mounted, colo r-keyed units, remote electrically adjustable and heated. Adjustment of both
mirrors is carried out from the driver's door switchpack.A slider switch selects the mirror to be adjusted, and a disc switch
adjusts the selected mirror to the required position. Mirror ad justment can only be made when the ignition switch is in
position I or II or the driver's door is open, and the selector switch is moved from the central position. The door mirrors also
automatically darken under control of the electrochromic interior rear view mirror. Mirror heating elements operate on
selection of backlight heating.
Automatic dipping of passenger door mirror for kerb view when reversing, is fitted as part of the memory pack. With the
ignition switch in position II, the mirror selector switch in the left or right position and reverse gear selected, automatic
dipping is initiated by moving the mirror toggle switch rearwards and releasing. On receipt of the dip signal, the passenger
door mirror is driven downwards either 7 degrees, bottom of travel, or 4,5 to 5,5 seconds, whichever occurs first.
Subsequent rearward movement of the toggle switch achieves further dipping of the mirror in the same increments and
sequence. The mirror can be manu ally returned to the normal memorised positi on by moving the toggle switch forward with
reverse gear selected. The mirror will auto matically return to memorised position on deselection of reverse gear, or moving
ignition switch from position II.
Door mirror fold-back where fitted, to facilitate parking in conf ined spaces, can be initiated when the ignition switch is in
position I or II, the mirror selector switch is in the centra l position and vehicle speed is below 19 km/h (12 mph). Mirror
fold-back is then initiated by moving the toggle switch rear wards and releasing it. The door mirrors are returned to the
normal driving position by agai n moving toggle switch rearwards. There is no speed constraint on this operation. In the
event of a fold-back mirror becoming 'out of position' due to acci dental impact, it must only be re-positioned by initiating
the fold-back sequence.
Loss of power supplies will result in loss of mirror fold-back memory. In the event of such a memory loss with mirrors in the
normal position, fold-back will operate on second movement of the toggle swit ch. On loss of memory with mirrors in the
fold-back position, they will return to the no rmal position on next fold-back operation.
Bumpers
Each bumper comprises a beam mounted to the body via two strut assemblies, and a moulded polypropylene cover
incorporating side armatures and chrome plated blades. Each strut is secured to the BIW by three bolts and supports the
beam on a single bolt/height adjuster. The front bumper cover which is moulded to form a lo wer air intake for the cooling
pack, also incorporates left and right handed twin fog lamps, brake coolin g ducts. Side marker lamps fitted for some
markets serve only as reflectors for UK and Europe. A plastic undertray secured to the lower edge of the front bumper,
improves airflow and minimises the ingres s of road grime in that area. Standard bumpers have glass mat thermoplastic
(GMT) beams mounted on GMT struts. For certain markets, aluminium bumper beams are installed on menasco energy
absorbing struts. Whilst both types of front bumper provide a fu lly integrated 'soft front end' that satisfies bumper impact
requirements, the energy absorbing front and rear bumpers are further designed to withstand 5mph (8kph) impacts with no
visible damage sustained. Side markers/re flectors, and direction indicators are designed for ease of ac cess from the outside
of the bumper. For adjustment and bulb change, the fog lamps are accessed from th e bumper interior. The bumper covers
are body coloured and matched. Replacement covers are supplied complete with side armatures and are finished in primer
Trunk
The trunk houses the spare wheel, the battery, an electrical carrier containing electrical fuses, relays and modules and a
compact disc auto-changer attached to body bracketry. The trun k is fitted with push-fit liners to the sides and front inner
panel.The carpet covered floor is in two removable sections, one covering the spare wheel and wheel changing equipment,
the other covering the battery and electrical carrier. The front and rear edges of the floor board loca te in blocks on the fuel
tank backboard and the rear of the body , which provide two height settings to accommodate the difference in thickness
between the space saver and full sized spare wheels. A moulded finisher covering the rear of the trunk below the sill is
secured to the rear panel by tabs and fir tree fasteners. Finisher panels fitted over the rear lamp units provide for access
from the trunk. Finisher panels fitted to the rear lamp units provide trunk inte rior access to the lamps. The trunk lid
underside is fitted with a removable mo ulded liner and two trunk illumination light s. Trunk locking is based on a central
latch and striker, operated electrically through the central lo cking system by an adjacent actuator or by key in a barrel lock

cooling duct.
The windshield washer is operated by pressing the button at the end of the wiper control stalk switch. Pressing and
releasing the button operates the washer for 1 to 1.4 seconds and the wiper completes three sweeps. An optional drip wipe
function adds a further sweep of the wiper after a 4 second delay, to clear residual fluid from the windshield. If the button is
held depressed, the washer and wiper will operate continuous ly for up to 20 seconds. When the button is released, the
wiper will again complete three further sweeps.
Headlamp Powerwash

The headlamp powerwash system incorporates a chromed twin nozzle assembly mounted on the chromed bumper blade
immediately in front of each pair of he adlamps. Each nozzle assembly is connected via snap fittings to a powerwash pump
mounted adjacent to the windshield wash pump on the rear face of the washer fluid reservoir.The powerwash system
operates in conjunction with the windshield washers when the ignition switch is in position II and the headlamp switch is in
the dip or main beam position. When powerwash is initially activated, a wash cycle commences, consisting of two 400 ms
pulses separated by a three second delay. If powerwash is still selected on completion of this cycle, it will continue to
operate at the same frequency for a maximum period of 20 se conds. To conserve washer fluid, headlamp powerwash will
only function on every sixth operation of the windshie ld wash switch.When the 'WASHER FLUID LOW' message is
illuminated, the windshield washer will continue to operat e for a limited period but the headlamp powerwash will not
function until the fluid level is restored.
Rain Sensing System
The rain sensing system installed form so me markets, provides automatic wiper operation when rain is detected on the
windshield. The system detects differing le vels of rainfall and varies wiper operation ranging from intermittent to maximum
continuous, to suit prevailing requirements.
The system which is brought into operation by selecting AUTO on the wiper control switch bezel, does not preclude normal
manual control of wiper operation.
The system consists of a rain sensor, an electronic control module and a dedicated wiper control switch.
The rain sensor is an optical transducer that is sensitive to changes in infra-red light penetration of the windshield created
by the refractive effects of water drople ts. The sensor elements consist of two groups of light emitting diodes which
alternately project infra-red light onto th e windshield and a photo-diode that receiv es resulting reflections from the glass. A ll
of the infra-red light is reflected back from a moisture-free windshield, resulting in a contact 5V output signal from the
sensor and no wiper activation. Rain falling on the light sensing area of the wi ndshield results in refraction and diffusion of a
proportion of the projected light with a corresponding imbalance of light received by the photodiode. This results in pulsed
outputs from the sensor, the frequency and duration of which are directly proportional to the number and size of water
droplets respectively. These pulses together with wiper switch position signals are received by the sensor control module
and processed to mimic column switch gear operation. In this recognisable form, signals are input to the body processor
module (BPM) where they are interprete d as normal wiper operation requests.