coolant temperature JAGUAR X308 1998 2.G Service Manual

Ref #12 DEF (resumes the system on at the previous temperature setting).
Button (switch) logic
All buttons with an integral LED state lamp conform to the following operating logic.
When the state lamp is lit the relevant func tion is operational. From this condition, pressing the button will de-activate the
function, confirmed by the LED being de-energized and the pres ence of a single audible 'beep'. A single 'beep' will
accompany the state lamp to confirm function re-selection.
1. 1. ON / OFF and manual fan speed.
Pressing this knob activates the system ON at the last settin g or switches the system OFF. Rotate the knob clockwise to
increase and anti-clockwise to decrease fan speed and thus airflow.
With the system OFF, ram air is available by the selected air di stribution mode (indicated by state lamp). Air flow will NOT
occur unless a manual air distribution mo de is selected, this air being unconditioned and flow dependent upon vehicle
speed.
• NOTE: The blowers are inhibited until the engine coolant te mperature is > 35°C, unless DEFROST, FACE or DEMIST modes
are selected.
2. 2. Manual Air Recirculation
Closes the outside air intakes of the blower asse mblies and recirculates air within the vehicle.
Two options of control are available :
Timed Recirculation. Pressing the button for less than 1.5 seconds lights up the LED (confirmed by a single bleep).
This provides recirculation of interior air for a period of approximately 5 minutes. Pressing the button within five
minutes returns the system to fresh air intake mode.
Continuous Recirculation. Pressing and holding the button for more than 1.5 seconds lights up the LED (confirmed by two beeps). This provides continuous reci rculation of interior air. Pressing the button returns the system to fresh air
intake mode.
• NOTE: Avoid using manual air recirculatio n for prolonged periods in cold weather, this may result in interior misting of
glass.
3. 3. Temperature Scale Selection
Press the appropriate button to display temperatures in degrees Celsius or Fahrenheit.
4. 4. Manual Fan Speed
Rotating the fan speed control knob (to vary fan speed) will di splay a proportional number of horizontal bars on the LCD.
There are total of eleven manual fan speeds available.
5. 5. Temperature Display
Indicator of internal demand temperatur e or external ambient temperature. The external ambient is updated every 4
seconds when the road speed > 25 km / h.
6. 6. Scale
Selected temperature scale, Celsius or Fahrenheit.
7. 7. External temperature
Symbol indicates when this option is selected

Inputs / Outputs
1.1. Engine speed:
Input to the A/CCM from the ECM. Heated windshield and backli ght will be inhibited when engine speed < 50 RPM.
2. 2. Vehicle speed:
Input from the instru ment cluster. Blower speed control to minimise the effects of ram ai r. Road speed compensation is inhibited when maximum
cooling LO, or maximum heating HI, is selected; also inhi bited in defrost mode with airflow set to maximum.
Used to determine the frequency at which the exterior temperature display is updated.
3. 3. Coolant temperature (signal derived from ECM via instrument cluster):
Input from the heater matrix temperature sensor used to control water valve and thus vent temperatures. Used to monitor the temperature of coolant at the heater matrix to assist the control of air outlet temperature. Used to inhibit the blowers when heating is selected and the engine coolant temperature is below 30°C. Is used to provide progressive increase in blower speed up to 60°C. To inhibit the water valve and pump when the coolant temperature is = < 10°C
Sensors and Controls
Solar Sensor

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:

RH and LH Air Intake (Fresh / Recirc) Center Vent Defrost Foot Cool Air Bypass
Blower Motor Control.
The A/CCM controls the speed of two blower motors which deliver airflow to the air conditioning unit. The blower motors are
regulated by power transistor modules which pr ovide a linear variation of blower speed.
Filter Compensation
Where particle filters are fitted as 'after market' items the A/CCM program must be changed to allow higher AUTO blower
speeds; this compensates for the slight loss of air flow. Access to the program is by PDU.
Vehicles with filters fitted OEM will have this facility enabled by Jaguars Cars Ltd.
Relationship Manual Contro l Blower Speed / Voltage
• NOTE: Blower motors are inhibited when the engine coolant temperature is below 35°C and heating is demanded, unless
DEFROST / DEMIST is selected.


Blower ModeDisplay Output - No of BarsBlower Motor Voltage (V)
OFFNil0.0
Manual LO14.00
24.33
Manual M124.67
35.00
Manual M235.33
45.67
46.00
Manual M346.33
56.67
Manual M457.00
67.33
67.67
Manual M568.00
78.33
78.67
Manual M679.00
89.33
89.67
Manual M7810.00
910.33
Manual M8910.67
1011.00
Manual M91011.33
1111.67
Manual HI and DEFROST1112.00

Connector Pin Identity Chart for AC003

Connector Pin Identity Chart for AC004

Pin NumberCircuitCircuit Function
001Solar sensor
002Center vent servomotor feedback potentiometer
003RH air intake servomotor feedback potentiometer fresh / recirculation
004Not used
005Cool air bypass servomotor feedback potentiometer
006Coolant temperature signal
007RH blower motor voltage feedback
008RH blower motor drive signal
009Not used
010Defrost servomotor feedback potentiometer
011LH air intake servomotor feedback potentiometer fresh / recirculation
012Not used
013Foot servomotor feedback potentiometer
014Not used
015LH blower motor voltage feedback
016LH blower motor drive signal
Pin NumberCircuitCircuit Function
001Screen request to ECM
002CLOCK signal to control panel
003DATA OUT signal to control panel
004Compressor lock signal
005Exterior air temperature sensor
006Heater matrix temperature sensor
007DATA IN signal from control panel
008START signal to control panel
009Not used
010Compressor lock select
011In-car temperature sensor
012Evaporator temperature sensor

The In
strument Cluster is the primary electronic control module for the speedomete
r, tachometer, coolant temperature, fuel
level, driver information (Message Centre) and warning lamps.
The Instrument Cluster also:
- provides input / output informatio n signals for use by other modules.
- acts as a protocol converter (software language translator - the languages used on each network are very similar, but
neither can be directly interp reted by the opposite system) for communication between all modules on both the CAN and
SCP multiplexed networks. The Instrument Cluster is the only module on the vehicle which communicates between the two
networks.
Instrument Cluster Gauges

*Not used on all markets. Refer to the Drivers Handbook.
Although the gauges look like conventional analogue gauges, each pointer is driven by a stepper motor to provide more
12Ai
rbag Circuit Integrity
13Adaptive Damping
14Body Processor

Module
It

em
De
scription
1Low Fu

el Level
2Exhaus

t System Temperature *
3E

ngine Coolant High Temperature
4Di

rection Indicator Right Hand
5Side

/ Parking Lamps
6Handbrake ON / Low
Bra
ke Fluid Level
7Main

Beam
8Ai

rbag / Airbag System Fault
9Hi

gh Priority Text
Message Displayed
10M
essage Centre (Text Messages)
11Low Pri

ority Text Message Displayed
12Se

at Belt Not Fa
stened (Driver's)
13ABS Integrity
14EMS Fault
15D
irection Indicator Left Hand


accu

rate readings.
Refer to Section 413-08 for details of the Driver Information / Message Center.