1998 JAGUAR X308 air condition

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

The heater matrix temperature sensor is a thermistor which changes its electrical resistance in response to changes in air
temperature converting a temperature rating to an electrical signal.
The sensor connector is located on the RH SIDE of the air conditioning unit. The sensor bead is located inside the unit down-
stream from the heater matrix and measures the 'post-heater' air temperature, before the air is distribu ted to the cabin The
sensor provides a signal to the A/CCM which adjusts the duty ratio of the water valve to provide the required air
temperature from the heater.
Ambient Temperature Sensor
The sensor is a thermistor which changes its electrical resistance in response to changes in air temperature, converting a
temperature rating to an electrical signal.

The ambient temperature sensor measures exterior air temper ature and is mounted on the crossbeam, in front of the
condenser on the LH side.

The signal from the ambient sensor allo ws the A/CCM to compensate for the ambient conditions and to display the
information on the control panel - updated every four (4) seconds.
Sensor response is 'damped' by the A/CCM and ther efore does not appear to react to temperature chan
ges as quickly as the

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 FC043

Control Panel Communication
The control panel provides operator interface with the climate control system.
Control panel operation is described in detail in the D section.
Control Panel Inputs (I/P) / Outputs (O/P)
Pin NumberCircuitCircuit Function
001Ignition positive supply
002Battery isolate supply
003Auxiliary ground
004Auxiliary ground to control panel
005Battery supply
006Engine speed input
007Electrical load drive inhibit
008+5V sensors
009Clutch request to ECM
010Diagnostic L-line
011Not used
012Ignition (positive) to control panel
013System ground
014Ground to control panel
015Air conditioning isolation relay
016Vehicle speed
017Pressure switch
018Aspirator motor (In-car sensor)
019Sensor ground
020Logic ground for diagnostic lines
021Diagnostic K-line
022Not used
Pin NumberCircuitCircuit Function
1Input CLOCK
2Input START
3Input DATA IN
4Output DATA OUT
5Input ignition (positive)
6Input auxiliary (negative)
7Ground
8Dimmer
9Dimmer override
10Not used
11Not used
12Not used

System Self-test
Other conditions which may exist but will NOT log fault codes:
Associated Faults
System Self-test
Panel Communication Check
The panel communication check veri fies the inputs and outputs from the control panel to the A/CCM.
Actuator Check Procedure
The system self test procedure drives all the actuator moto rs, to check their operation. If an actuator is operating
incorrectly or operating outside of its limi ts then a fault code will be present.
Before commencing with the actuator check procedure, ensure the ca r is operating under normal conditions.
1. 1. Switch ignition OFF.
2. 2. Press and hold the RECIRC and AUTO buttons simult aneously, switch ignition ON and run the engine.
3. 3. All the control panel LEDs and all LCD segments will flas h on and off. Any function LED indicator which does not
flash on / off suggests a fault condition within that area of the panel or, with the LED.
Any LCD element which fails to flash on / off indicates a fault within the display element or panel.
4. 4. Press AUTO
43 Cool air by-pass
motor faultHarness / connector fault
Servo motor seized or sticking
Flap seized or sticking
*
*
*Refer to PDU
*
43 Cool Air by-pass
motor faultHarness / connector fault
Servo motor seized or sticking
Flap seized or sticking
*
*
*Refer to PDU
*
44 Defrost vent motor
faultHarness / connector fault
Servo motor seized or sticking
Flap seized or sticking
*
*
*Refer to PDU
*
45 Centre vent motor
faultHarness / connector fault
Servo motor seized or sticking
Flap seized or sticking
*
*
*Refer to PDU
*
46 Foot vent motor
faultHarness / connector fault
Servo motor seized or sticking
Flap seized or sticking
*
*
*Refer to PDU
*
SymptomPossible SourcesAction
No heatAirlock in system.
*Refer section 303-03 for fill / bleed procedure
*
Heater water pump inoperative
Coolant flow valve stuck closed
*
*Check operation and circuit
*
Faulty engine coolant thermostat
*Renew as required
*
One vent failing to open / closeBroken linkage.
*Renew as required
*
Poor airflowBlower motors - incorrect operation
*Check operation and circuit
*
ItemCheck LEDCondition
IgnitionDefrostIGN input at 12V, check LED is illuminated
AuxiliaryFaceAUX input at 12V, check LED is illuminated
ClockFeet / faceClock input normal, check LED is illuminated
Start inputFootStart input normal, check LED is illuminated
Data outScreen / footData out input normal, check LED is illuminated
Dimmer overrideRecirc.Dimmer override input ON, check LED is illuminated

5.5. Press RECIRC button to instigate actuator check mode.
6. 6. Press FACE to cycle through the actu ator mode conditions 20 to 27.
7. 7. Press the FAN button to restore normal operation with default panel settings, ie AUTO @ 24°C.
Actuator Fault Codes
• NOTE: * The water valve operates on a 6 second pulse, ie 3 seconds ON, 3 seconds OFF.


Outlet
Code Blower Level Centre vent Foot Defrost Cool air by-pass Fresh / Recirc. Compressor Water valve Water pump
200openclosedclosedclosedfreshOFFclosedOFF
211openclosedclosedclosedfreshOFFclosedON
2210openclosedclosedopenhalf openA/C ONclosedON
2317bleedhalf openclosedhalf openhalf openA/C ON6s pulse * ON
2417bleedhalf openclosedclosedrecirc.A/C ON6s pulse * ON
2523closedopenbleedclosedrecirc.A/C ONopenON
2623closedhalf openhalf openclosedrecirc.A/C ONopenON
2731closedclosedopenclosedopenA/C ONopenON