Climate Control Systems
SECTION CON TENTS
Subsection Title SRO Page
14.1 ............. System Description ................................................................... 1
14.2 ............. Component Descriptions .............................................................. 3
14.2.1 ............ Control Panel ........................................................................\
3
14.2.2. ........... Control Panel Inputs / Outputs ......................................................... 3
14.2.3. ........... Solar Sensor ........................................................................\
. 4
14.2.4. ........... Engine Speed Signal .................................................................. 4
14.2.5 ............ Ambient Temperaturesensor ........................................................... 4
14.2.6 ............ Vehicle Speed Signal ................................................................. 4
14.2.7.
........... Evaporator Temperature Sensor ......................................................... 4
14.2.8. ........... Heater Matrix Temperature Sensor ...................................................... 5
14.2.9.
........... Coolant Temperature Signal ............................................................ 5
14.2.10
.......... Compressor ONSignal ................................................................ 5
14.2.11 ........... Motorized ln-car Aspirator ............................................................ 5
14.2.12 .......... CompressorLockSignal ............................................................... 5
14.2.13
.......... Refrigerant Pressure Switch ............................................................ 5
14.2.14
.......... Water Valve ........................................................................\
. 5
14.2.15 .......... Water Pump ........................................................................\
. 5
14.2.16
.......... Servo Motor Control .................................................................. 6
14.2.17 .......... Blower Motor Control ................................................................ 6
14.2.18 .......... Differential Control ................................................................... 6
14.2.19
.......... Heated Rear Window, Door Mirrors and Front Screen ...................................... 6
14.3 ............. Climate Control Module Connections ................................................... 7
14.4 ............. Climate Control System Test .......................................................... 10
14.4.1
............ Fault Code Extraction and Deletion Procedure ........................................... 10
14.5
............. Fault Codes ........................................................................\
11
14.6 ............. Actuator Check ..................................................................... 12
14.7
............. Diagnostic Tests .................................................................... 13
14.7.1
............ Fault Code 11 ...................................................................... 13
14.7.2.
........... Fault Code 12 ...................................................................... 14
14.7.3
............ Fault Code 13 ...................................................................... 15
14.7.4.
........... Fault Code 14 ...................................................................... 16
14.7.5
............ Fault Code 15 ...................................................................... 16
14.7.6
............ Fault Code21 ...................................................................... 17
14.7.7 ............ FaultCode22 ...................................................................... 17
14.7.8 ............ Fault Code23 ...................................................................... 18
14.7.9. ........... Fault Code 24 ...................................................................... 18
X300 EDM i Issue 1 August 1994
Climate Control Systems
Subsection Title SRO Page
14.7.10 .......... FaultCode31 ...................................................................... 18
14.7.11
........... Fault Code32 ...................................................................... 19
14.7.12
.......... Fault Code33 ...................................................................... 19
14.7.13
.......... FaultCode34 ...................................................................... 20
14.7.14
.......... FaultCode35 ...................................................................... 20
14.7.15 .......... FaultCode36 ...................................................................... 21
14.7.16
.......... Fault Code41 ...................................................................... 21
14.7.17
.......... Fault Code42 ...................................................................... 21
14.7.18
.......... FaultCode43 ...................................................................... 22
14.7.19
.......... FaultCode44 ...................................................................... 22
14.7.20
.......... Fault Code45 ...................................................................... 22
14.7.21
.......... Fault Code46 ...................................................................... 22
14.7.22
.......... BlowerMoto rs ...................................................................... 23
14.7.23
.......... Water Valve ........................................................................\
25
14.7.24
.......... Water Pump ........................................................................\
25
Climate Control Systems
.-)
14.1 SYSTEM DESCRIPTION
The Air Conditioning electronic Control Module (A/ CCM) located on the right-hand side of the A / C unit, controls the 0 functions of the system.
These functions include:
0 In-car temperature control
0 In-car humidity control (Air conditioning vehicles only)
0 Air flow / volume and distribution
The temperature of the passenger compartment is continuously compared with the temperature selected on the con
- trol panel LCD. A digital microprocessor within the A/ CCM receives the data signals. Comparison of these signals
and those from system temperature sensors and feedback devices results in the appropriate output voltage changes
needed to vary the blend of air flow into the passenger compartment.
The climate control system peripherals communicate with the A/ CCM via three main device categories comprising
of manual inputs, automatic outputs and inputs, as shown
in Fig. 1.
Air Temperature Control I
9 Recirculation switch
. Air con on/off switch
System on/off switch
. Auto. / Man. select
Set temperature
. Air flow outlet mode set
Heated front screen switch
. Heated rear screen &
heated mirror switch
. External temp. display
switch
. FahrenheiVCentigrade switches
4
. Solar sensor
. Motorized in-car aspirator
. Ambient temp. sensor
. Evaporator temp. sensor
Heater matrix temp. sensor
. Compressor lock sensor
. Face differential temp. control
. Refrigerant pressure switch
. Engine speed signal
Engine coolant temperature
Vehicle speed signal
. Circulation pump
. Water valve
. Power transistor (fan speed
Servo motor potentiometers:
signal
control)
LH air inlet flap
RH air inlet flap
Centre vent flap
Foot flap
Defrost flap
Air by
-pass flap
Air Inlet Control
9 LH air inlet
. RH air inlet
CONTROL PANEL
1
A / CCM
I I
I . External temp. display I
. Coolant recirculation valve
. Coolant recirculation pump
LH blower motor & power transistor
. RH blower motor & power transistor
. LH high speed relay
Air Distribution Control
Servo motor for:
9 Centre vent flap
Foot flap
Defrost flap
Fig. 1 Schematic view A / CCM Inputs & Outputs
X300 EDM 1 Issue 1 August 1994
Climate Control Systems
28-
I llSA I
1.
2.
3.
4.
5.
6.
7.
8.
9.
IO.
11. 12.
13.
14.
15.
21J 20
Instrument pack
Fascia switch pack
Defrost servo.
Air distribution box Solar sensor
Control panel
Centre console
LH blower motor
Water valve
Circulation pump
Coolant temperature sensor
LH front fuse
-box
Circulation pump relay
Ambient temperature sensor
A
/ C compressor
17
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27. 28.
29.
16 1's J86 1767
Compressor clutch relay
Trinary pressure switch
Radiator fan pressure switch
Control module
RH blower motor
Engine control module
Motorized
in-car aspirator
A
/ C isolate relay
RH blower motor high speed relay RH blower motor relay
LH blower motor high speed relay
LH blower motor relay
-
-
Fig. 1 Component Location Diagram
Issue 1 August 1994 2 X300 EDM
Climate Control Systems
14.2.8 Heater Matrix Temperature Sensor
This sensor is positioned inside the air conditioning unit just
downstream of the heater matrix. The sensor monitors the
post
-heater air temperature, before the air is distributed to
the passenger compartment. In conjunction with the A / CCM this sensor provides the input to maintain a constant
outlet temperature.
14.2.9 Coolant Temperature Signal
This input is required to provide blower inhibit control, to
avoid cold
air being delivered in heating mode when the en- gine coolant temperature is below 3OOC. The input also
monitors the temperature of the coolant delivered to the
heater matrix to assist outlet temperature control.
14.2. IO Compressor ON Signal
This signal line monitors the compressor relay to inform the
A/ CCM of the compressor status and to facilitate lock detec-
tion and error sensing.
14.2.11 Motorized In-car Aspirator (Fig. 1)
The Motorized In-car Aspirator (MIA) detects the air tem- perature within the passenger compartment. A small motor
driven fan (blown aspirator) draws air across the thermistor,
which changes its electrical resistances in response to
changes in air temperature, converting
a temperature rating
into an electrical signal.
The MIA is located on the back of the driver's side knee
bolster.
14.2.12 Compressor Lock Signal - 12 cy/. vehicles only
This signal provides the A / CCM with compressor rotation
speed. This is then compared with engine rotation speed.
If the ratio of the compressor speed against engine speed
drops belowthe A/CCM limits, indicating compressor/ belt
slippage, the compressor clutch is disengaged.
When compressor clutch disengaging commences the A/C
LED on the control panel will flash once per second.
14.2.13 Refrigerant Pressure Switch (A/C Vehicles only)
The refrigerant pressure switch (Fig. 2) is located under the
hood on the liquid line.
The switch contacts open when abnormal pressures are
sensed. This action inhibits the compressor clutch drive.
14.2.14 Water Valve
The water valve is used in conjunction with the water pump
to regulate the output air temperature. The water valve is off when the ignition is on, engine not running.
14.2.15 Water Pump
The water pump is energized in all engine running modes
except for under cold coolant condition at blower inhibit and
in panel
off mode. The water pump is off when the ignition
is on, engine not running.
If
J82-488
KI Fia. 1 I
Fia. 2
X300 EDM 5 Issue 1 August 1994
Climate Control Systems
0
0
14.3 CLIMATE CONTROL MODULE CONNECTIONS
Fig. 1 Control Module Connector Pins
J80-098
IGN, activated high
0 Io(22-way) Input Diagnostic L-Line
11 (22-way) Input Water pump motor current Current detection resistance 7mQ
12 (22-way) Output Ignition (+VE) to control panel
13 (22
-way) System Ground
14 (22
-way) Output Ground to control panel
15 (22
-way) Output Air con isolation relay Activated when IGN ON and for 30 sec-
16 (22-way) Input Vehicle speed input
17 (22
-way) Input Pressure switch Ground for normal pressure.
IGN+ for abnormal pressure
18 (22
-way) Output Aspirator motor (In+ar sensor) 0.05A at 12V, activated high during ON
mode only
19 (22
-way) Input Sensor ground
20 (22
-way)
21 (22
-way) Output Diagnostic K-Line
onds after IGN OFF
Logic ground for diagnostic lines
X300 EDM 7 Issue 1 August 1994
Climate Control Systems
0 14.5 FAULT CODES
J&&: Displayed error codes are NOT compatible with Jaguar Diagnostic Equipment (JDE).
23 Refrigerant Pressure Switch Open /short circuits. Low gas charge*
24 Differential Potentiometer. Open /short circuits
31 LH Fresh
/ Recirc.
Potentiometer I I I I RH Fresh / Recirc. Potentiometer
Open / short circuit in pot. feed.
32
, In certain
circumstances, the motor can over- 0 33 Cool Air Bypass Potentiometer
34 Defrost Potentiometer travel and log further faults.
35
36 Foot Potentiometer Cycling
the ignition two or three times can cure
this.
Centre
Vent Potentiometer
41
42
I LH Fresh / Recirc. Motor
I RH Fresh / Recirc. Motor
43 Cool Air Bypass Motor
44 Defrost Motor lines. Motor flap sticking
/ jammed.
Check
for short
/ open circuits in motor drive
1 45 I Centre Vent Motor I
1 46 IFoot Motor I
W: In ambient temperatures below OOC, the system may log fault code 23 because low ambient can cause a tem-
porary low gas pressure. In ambient temperatures above 35"C, the system may log fault code 23 as temporary
high pressure can exist within the system. *
Associated Faults
Other symptoms that may exist without storing fault codes:
Airlock in system.
Water pump inoperative.
Water valve stuck closed.
Faulty engine coolant thermostat.
Broken linkage.
Blower motors
- incorrect operation.
No heat
One vent failing to open /close
Poor airflow
X300 EDM 11 Issue 1 August 1994
Climate Control Systems
High speed operation at all times - RH blower
a Cause:
1. Faulty high speed relay.
2. Faulty harness wiring.
Remedy:
1. Check the relay contact is not stuck 'ON'.
2. Check continuity of wiring harness between blower motor pin 8 and ground, pin 10 and A / CCM pin 42 (16-way connector) and pin 13 and A/ CCM pin 41 (16-way connector).
High speed operation at all times - LH blower
Cause:
1. Faulty high speed relay.
2. Faulty harness wiring.
Remedy:
1. Check the relay contact is not stuck 'ON'.
2. Check continuity of wiring harness between blower motor pin 8 and ground, pin 10 and A / CCM pin 50
(16-way connector) and pin 13 and A / CCM pin 49 (16-way connector).
14.7.23 Water Valve
For mechanical diagnosis of the water valve, refer to section 14 of the Vehicle Service Manual.
The solenoid coil fitted to the water valve housing has
a resistance of 17.4Q f 1P at 5 - 35 "C.
Check the continuity between pin 2 water valve white 2-way multi-plug and the A/ CCM (pin 52,26-way connector).
Check for ground
at pin 1 water valve white 2-way multi-plug.
14.7.24 Wafer Pump
Disconnect the black 2-way connector.
The motor operation can be checked by applying battery voltage to pin 1, motor 2
-way connector, and ground to pin 2.
Inspect the harness for open circuit or short circuit to ground. Rectify as necessary. If no harness faults are apparent,
renew the
A / CCM.
CAUTION: If removed the water pump should not be operated dry, and for a maximum of five minutes when wet. Failing to observe this may result in pump rotor and shaft damage.
The application of reverse polarity voltage at pins 1 and 2 will result in damage to the pumps internal cir-
cuitry.
X300 EDM 25 Issue 1 August 1994