heater JAGUAR XJ6 1994 2.G Electrical Diagnostic Manual

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
.-)
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
System Differences
m:
Heater only vehicles do not have the following fitted:
This section applies generally to both air conditioning and heater systems. System specific descriptions, pro-
cedures, tests etc. are indicated.
0 Solar sensor
0 Clutch request and acknowledge circuitry.
0 Refrigerant pressure switch.
0 Control panel - deletion of air conditioning button.
6 cyl. engined vehicles do not have either the electrical load inhibit or the compressor lock sensor.
Heated Front Screen
(HFS) is optional on both air conditioning and heater panel versions.
14.2 COMPONENT DESCRIPTIONS
14.2.1 Control Panel
The control panel (Fig. 1) provides the operator interface with the climate control system.
The control panel communicates with the
A / CCM via a serial data communications link. During each data transfer
cycle the control panel states whether it is an air conditioning or heater version, thus enabling the A/ CCM to control
the system functions accordingly.
Tontrol panel operation is described in detail in the 'Climate Control Systems' section of the VSM.
-
Fig. 1 Control Panel (A / C with Heated front Screen)
J86 - I726
14.2.2 Control Panel Inputs /Outputs
Description I CableColor
I 1 I Output clock I Grey I
2 Output start Grey / Red
3 Input data
in Grey / Yellow
4 Output
data out Grey / Green
5 Output
ignition positive White / Red
6 Output auxiliary positive
White / Blue
7 Output
ground Black
8 Dimmer
Red
9 Dimmer override Red / Green
I 10 I Not connected I- I
I 11 I Not connected I- I
I 12 I Not connected l- I
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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
14.2.16 Servo Motor Control
The system incorporates several servo motors which direct the flow of air through the air conditioning system. The
motors are driven by A / CCM signals in either a clockwise or anti-clockwise direction.
Servo motor position is monitored via
a feedback potentiometer situated within the motor housing.
The system servos comprise:
o RH and LH Air intake servos (Fresh / Recirc.).
0 Centre vent servo.
o Defrost (screen vent) servo.
0 Footservo.
0 Cool air by-pass servo.
14.2.17 Blower Motor Control
The A/ CCM controls two blower motors, delivering airflow
to the evaporator / heater unit, at variable fan speeds. The
blower motors are regulated by power transistor modules
which provide linear variation of blower speed; the blower
speed
is increased or reduced progressively in response to
vehicle speed, minimising the ram effect of forward motion.
The blower motors are inhibited when engine coolant tem
- perature is below 30°C and heating is requested.
14.2.18 Differential Control
The differential control is mounted on the facia centre vent. It is used to control the temperature difference between the
upper and lower outlets. Fig.
1 Servo
Motor
14.2.19 Heated Rear Window, Door Mirrors and Front Screen
The Heated Rear Window (HRW) function can only be activated with the ignition on and the engine running. Operation of the HRW switch operates the status condition LED on the control panel and switches on the HRWfor approximately 21 minutes. Selection of the HRW also operates the door mirror heaters for approximately 11 minutes. The operation
can be cancelled by switch re-selection or ignition off. System off does not cancel the HRW operation.
The Heated Front Screen
(HFS) function can only be activated with the ignition on and the engine running, and either
‘defrost’ mode selected or HFS selected. Each half, left and right hand split, switches on for approx. 6.5 minutes. The
operation can be cancelled by switch re-selection or ignition off. System off does not cancel the HFS operation.
0
0
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Climate Control Systems
14.7.4 Fault Code 14
Coolant Temperature
Input
0 Sensor, harness or A / CCM open circuit.
0 Sensor, harness or A / CCM short circuit to ground.
This input is derived from the instrument pack,
a continuity check can be carried out from pin 22, instrument pack (24-wayconnector), to pin 40 (16-way connector) of the A / C CM.
The instrument pack input from the engine coolant temperature sensor, is covered in the EDM, section 15, Instrument
Pack and Trip Computer.
14.7.5 Fault Code 15
Heater Matrix Temperature Sensor
0 Sensor, harness or A/ CCM open circuit.
0 Sensor, harness or A / CCM short circuit to ground.
This sensor measures the temperature of the heater matrix.
If the signal on pin 28 (12-way connector) remains at less than 1 volt, suspect either a short circuit to ground on the
signal wire or an open circuit on the 5 volt supply to the sensor. If the signal on pin 28 rises to approximately 5 volts
then suspect an open circuit on the sensor ground.
Checkthevoltage, against the graph below (Fig.
I), measured between pin 28 (12-way connector) and pin 19 (22-way
connector) A / C CM.
If the voltage is within the set limits, the system is operating correctly.
A resistance check can be carried out on the sensor and should conform with the figures below, measured between
pin 28 (12-way connector) and pin 19 (22-way connector) A/ C CM.
0°C 4.6
-5.1 lclL 15°C 2.1 - 2.6 lclL
If the resistance is outside the set limits, renew the sensor.
1ynfe:
Inspect sensor harness for open circuit or short circuit to ground. Rectify as necessary.
If the voltage is outside the set limits, renew the A / CCM.
The
resistance should continue to decrease as the temperature increases and vice versa.
*C
V
J86-1771
Fig.
Issue 1 August 1994 16 X300 EDM

Climate Control Systems
14.7.22 BLOWER MOTORS
Disconnect the blower motors (LH & RH) multi-plugs and check motor operation by applying battery voltage (+12V) across pin 5 (+vel and pin 9 (-ve).
Non-functioning of both L H and RH motors *
Cause:
1. Loss of ignition voltage.
Remedy:
1.
2.
*
Examine fuse F12 in RH heelboard fuse-box. If fuse is blown determine reason for failure and renew.
Examine harness wiring from
RH heelboard fuse-box connection CA044/010 to splice CAS53. Repair or renew
wiring as necessary.
This fault will also affect the operation of seat control modules, power steering control module and door mirror
heaters.
Non-functioning of RH blower motor only
Cause:
1. Faulty relay operation.
2. Faulty harness wiring.
Remedy:
1. Ensure 12Vsupply between relay pin 1 and ground.
Ensure continuity between pins 3 and
5 when relay operated.
Ensure relay coil impedance of
7552 to 135Q across pins 1 and 2.
Ensure correct seating of relay on base. Examine pins for damage or deformity.
Check continuity of wiring from fuse F12
(RH heelboard fuse-box) to relay pin 1 and from relay pin 2 to A / CCM
pin 53 (26-way connector).
Check continuity of wiring from fuse
F11 (RH heelboard fuse-box) to relay pin 3, from relay pin 5 to motor pin 5, from motor pin 13 to A / CCM pin 41 (16-way connector), from motor pin 8 to ground and from motor pin 10 to A / CCM pin 42 (16-way connector).
2.
Non-functioning of L H blower motor only
Cause:
1. Faulty relay operation.
2. Faulty harness wiring.
Remedy:
1. Ensure 12V supply between relay pin 1 and ground.
Ensure continuity between pins 3 and
5 when relay operated.
Ensure relay coil impedance
of 7552 to 135Q across pins 1 and 2.
Ensure correct seating of relay on base. Examine pins for damage or deformity.
2. Check continuity of wiring from fuse F12 (RH heelboard fuse-box) to relay pin 1 and from relay pin 2 to A / CCM
pin 66 (26-way connector).
Check continuity of wiring from fuse
F11 (LH heelboard fuse box) to relay pin 3, from relay pin 5 to motor pin 5, from motor pin 13 to A / CCM pin 49 (16-way connector), from motor pin 8 to ground and from motor pin 10 to
A / CCM pin 50 (16-way connector).
X300 EDM 23 Issue 1 August 1994

Electrical rl
SECTION CONTENTS
Sub-Section 15.4 Driver Ergonomics
Sub-Section Title SRO Page
15.4 ............. Driver Ergonomics .............................................................. 15.4- 1
15.4.1 ............ System Description .............................................................. 7 5.4- 1
15.4.1.1 .......... Entry/ExitMode ................................................................ 15.4-1
15.4.1.2 .......... Driving Position Set ............................................................. 15.41
15.4.1.3 .......... PassengerSeatSet ............................................................... 15.4-1
15.4.1.5 .......... Reverse Mirror Dip .............................................................. 15.4-3
15.4.2 ............ System Components ............................................................. 15.4-3
15.4.2.1 .......... Seats - Driver and Passenger ...................................................... 7 5.4-3
15.4.2.3
.......... Seat Lumbar Pump .............................................................. 15.4-3
15.4.1.4
.......... RemoteRecall .................................................................. 15.43
15.4.2.2 .......... SeatMOtors .................................................................... 15.43
15.4.2.4 .......... Seat
Heaters and Thermostats ..................................................... 15.4-3
15.4.2.5 .......... Seatswitch Pack ................................................................ 75.45
15.4.3 ............ Seat Control Module ............................................................. 15.45
15.4.3.1 .......... Seat Control Module Connector Pins ............................................... 15.4-6
15.4.4.1 .......... Column Motors ................................................................. 75.48
15.4.4.3 .......... Driver / Passenger Rear View Mirror Motors ......................................... 15.4-9
15.4.4 ............ Steering Column /Mirror ......................................................... 75.48
15.4.4.2 .......... Column Joystick Switch .......................................................... 15.48
15.4.4.4 .......... Mirror joystick .................................................................. 15.49
15.4.5 ............ Column/Mirror Control Module ................................................. 15.4-10
15.4.6 ............ Non-Memory and Manual Applications ........................................... 15.4-12
15.4.6.1 .......... Non-Memory ................................................................. 15.4-12
15.4.6.2 .......... Manualseats .................................................................. 15.4-72
15.4.6.3 .......... Manual Column ............................................................... 15.4-12
15.4.7 ............ Symptom FlowChafls .......................................................... 15.4-13
15.4.8
............ Diagnostic Sub-routines ........................................................ 15.4-17
15.4.9.16 ......... Key to Schematic Diagrams ...................................................... 15.4-35
15.4.9 ............ Pin-Point Tests ................................................................. 15.4-19
15.4.10
.......... Electrochromatic Rear View Mirror ................................................ 15.4-36
15.4.10.1 ......... Description ................................................................... 15.4-36
15.4.10.2 ......... Test Procedure ................................................................. 15.436
X300 EDM V Issue 1 August 1994

15.4.1.4 Remote Recall
Remote activation of memory positions 1 and 2 can be achieved using the key fob transmitters (one per set of keys).
lfthe vehicle is unlocked using the remote transmitter the stored driving position will be adopted automatically. If the
vehicle is unlocked using the remote transmitter and an exit position is already set the corresponding entry position
will be adopted until the ignition key is inserted, the stored driving position will then be restored. 0 ~
15.4.1.5
Reverse Mirror Dip
On selection of reverse gear and operation of the mirror toggle switch downwards, the passenger side rear view mirror
will automatically tilt downwards to assist reverse parking. Upward adjustment disables reverse dip, a further down- ward adjustment when still in reverse gear reinstates reverse dip. The mirror will return to normal position when any
other gear position is selected.
15.4.2 SYSTEM COMPONENTS
15.4.2.1 Seats
- Driver and Passenger
The driver and passenger seat adjustment systems comprises the following components:
o Fore / aft motor
o Front raise / lower motor
o Rear raise / lower motor
0 Squab recline motor
0 Headrest motor
0 Lumbarpump
0 Squab heater
0 Inner cushion heater
0 Outer cushion heater
0 Heater thermostat
0 Switch pack
o Seat Control Module (SCM)
o Wiring harness
15.4.2.2 Motors
The five seat position adjustment motors are located below the seat cushions (horizontal and vertical adjustment) and
behind the squab (recline and headrest adjustment). Each motor unit incorporates a potentiometer which provides
directional movement position control via feedbackvoltage variations to the SCM. Positional variations are activated
by the SCM in response to signals from switches mounted on the seat switch pack.
15.4.2.3 Lumbar Pump
The lumbar pump, located behind the seat squab allows adjustment of seat rigidity by increasing/decreasing air pres- sure in the lumbar pad. The pump motor is controlled from a switch on theseat switch pack and governed by an in-line
pressure switch.
A solenoid valve is used to regulate air flow to the lumbar pad.
15.4.2.4 Heaters and Thermostats
The two cushion heaters and squab heater are regulated by a single in-line thermostat and operated by a switch
mounted on thecenter console switch pack. Operation of this switch causesthe Body Processor Unit (BPU) to energize a timed input to SCM (for 11 minute f 1) which in turn causes SCM to energize the heater supply. The supply will
remain on until timed out, although the heater circuit will be broken by the thermostat if the set temperature is ex- ceeded.
Note: Heatingcan only occur when the ignition switch is position I1 and the ambient temperature is belowthe thermo- stat pre-set value of 26°C.
X300 EDM 15.4 - 3 Issue 1 August 1994

rl E I ect r ical
15.4.6 NON-MEMORY AND MANUAL APPLICATIONS
15.4.6.1
Non-Memory
Seats, column and mirrors may be supplied without memoryfacilities on certain vehicles. In this case, adjustment of
each application is still controlled in the same way but the memory facility is disabled and the memory switch pack
not fitted.
15.4.6.2 Manual Seats
Manual seats are adjustable vertically and horizontally, vertical adjustment being motorized but horizontal adjustment
manually effected. The seats have heated cushions and squab, but are not operated by an electronic control module.
Control is effected using three relays, two for vertical adjustment and one for heating.
Vertical adjustment is requested
by operation of a switch located on the left-hand side of the seat front which completes
the electrical supply to either the raise or lower relay as required. When either relay is energized a change of contact
state connects one side of the motor to
+12V and the other side to ground. Reverse operation reverses supply and
ground connection.
Heating is still controlled by a timed output from the BPU. Operation of a switch located on the
center console indicates
to BPU that heating is required. Battery voltage is then applied to the heater relay for 11 minutes. The relay contact
completes the heater circuit, providing seat heating (and illuminating the switch surround) until the timer expires, or
optimum seat temperature is achieved. Operation of the heater switch before 'time-out' is achieved cancels the heat- ing request. Operation of the heater switch after 'time-out' has been achieved re-starts the heating cycle.
15.4.6.3 Manual Column
Manual column adjustment in the two planes is achieved by purely mechanical means, release catches allowing col-
umn movement within a fixed locking mechanism.