JAGUAR XJ6 1994 2.G Electrical Diagnostic Manual

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
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
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Climate Control Systems
Climate Control Module Connections, continued
35 (16-way) Input Solar sensor
36 (16
-way) Input Centre vent servo motor feedback po- tentiometer
37
(16-way) Input RH air intake servo motor feedback po- tentiometer F / R
38 (16-way) Not used
39 (16
-way) Input Cool air bypass servo motor feedback
potentiometer
I 40(16-way) llnput I Coolant temperature signal
1 41 (16-way) llnput I RH blower motor voltage feedback
I 42 (16-way) I Output I RH blower motor drive signal
I 43(16-way) I Input
I Differential potentiometer
44 (16
-way) Input Defrost servo motor feedback poten-
tiometer
45
(%-way) Input LH air intake servo motor feedback po- tentiometer - F / R
46 (16-way) Not used
47 (16
-way) Input Foot servo motor feedback potentiome-
ter
48 (16
-way) Not used
49 (16
-way) Input LH blower motor voltage feedback
50 (16
-way) Output LH blower motor drive signal
51 (26
-way) Input Compressor ON signal
52 (26
-way) Output Water valve
53 (26
-way) Output RH Blower motor relay
54 (26
-way) Output Heated front screen relays
55 (26
-way) Output Heated Door Mirror relay
Specification
Open collector R = 578, connected to
IGN, activated low
Open collector
R = IKn, connected to
IG N, activated high
Open collector R = IKQ, connected to
IGN, activated high
Voltage /temperature values
Voltage
/ temperature values
Open collector
R = IKQ, connected to
IGN, activated high
AJ16
- Ground (lock sensor not fitted)
VI2 - Ign. voltage (lock sensor fitted)
Voltage
/ temperature values
Voltage
/ temperature values
Voltage
/ temperature values
Resistance 6W.
&IO%
0% closed - IV, 100% open - 4V
Resistance 6Kn
+IO%.
0% closed - IV, IOW0 open - 4V
Pulse
width modulated signal I
OV to 3V max. I
Resistance IOW. &IO%.
Min. IV, Max. 4V
Resistance
6W. +IO%.
0% closed - IV, IOW0 open - 4V
Resistance 6W.
+IO%.
Resistance 6W. &IO%.
0% closed - IV, 10096 open - 4V
I
Battery voltage when compressor ON
1 amp at 12 volts
Load
36Q at 12V IGN, activated low
0
0
0
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Climate Control Module Connections, continued
69 (26-way) Output Defrost servo motor t-VE) Battery voltage when operated
70 (26
-way) Output Centre vent servo motor (-VE) Battery voltage when operated
71 (26
-way) Output Battery
voltage when operated
72 (26
-way) Output Battery
voltage when operated
73 (26
-way) Not used
LH air intake servo motor F / R (-VE)
RH air intake servo motor F / R (-VE)
74 (26-way) Not used
75 (26
-way) Output Foot servo motor (-VE) Battery voltage when operated
76 (26
-way) Output Cool air bypass servo motor (-VE) Battery voltage when operated
0
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Climate Control Systems
Actlon
Simultaneously hold FACE and FAN and switch the ignition
ON
14.4 CLIMATE CONTROL SYSTEM TEST
The control panel has a self-diagnosis feature, and is capable of displaying and deleting stored fault codes.
Climate control is an integrated system, therefore
it is recommended that the Portable Diagnostic Unit (PDU) is used
for fault diagnosis. The fault codes displayed with the control panel self-diagnosis feature are not as comprehensive
as those of the PDU. The PDU will display the relevant fault code, fault code description and information of the system
peripherals at the time the fault occurred.
Resu It
Control panel inputs for clock, start, data, ignition +ve and
auxiliary +ve are simultaneously examined and cause indi-
cator LED’s to illuminate on satisfactory line test.
14.4.1
System error information is stored in the A/ C CM up to a maximum of 5 faults. Should a fault occur there will be an
audible’beep‘and the message ‘Er’will be displayed on thecontrol panel LCD display for some 5 seconds after ignition
on. Please note that this will happen only once in any ignition switch cycle. The error source may be accessed by the
following procedure. A list and description of all accessible fault codes is provided on the following page.
Fault Code Extraction and Deletion Procedure
I Item Check LED
Ignition Defrost
Auxiliary Face
Clock Feet
/ face
Start input Foot
Data out Screen
/ foot
Dimmer override Recirc.
. Switch off the ignition.
Press and hold the ‘Auto’ and ‘Fresh / Recirc.’ buttons simultaneously, and switch on the ignition.
. All the control panel LED’s and all LCD segments will flash 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 panel or display element.
. Press ‘Auto’.
. Press ‘Face‘ to scroll through a maximum of 5 fault codes.
W
Thecontrol panel display will flash repeatedly indicating a list oftwo digit numbers (refer to following page for code
analysis).
. If, when a code is displayed, an accompanying ‘beep‘ is emitted, the indicated fault is current and therefore still pres- ent within the system. A code displayed without an accompanying ‘beep’ indicates a fault had previously occurred
but is not present within the system.
It is advisable to check all areas indicated with cleared fault codes. Such faults may re-occur if intermittent
problems are present in the system.
If
’0‘ is
displayed, there are no stored fault codes, wait 30 seconds to allow system self-test.
W:
. To delete stored and cleared fault codes simultaneously press ‘HRW and ‘FACE‘ switches.
. After investigating and correcting all stored faults, press the ‘Push Off button to restore normal operation with de-
fault panel settings, ie AUTO at 24OC.
Condition
IGN input at 12V, check LED is illuminated
AUX
input at 12V, check LED is illuminated
Clock
input normal, check LED is illuminated
Start input normal, check LED is illuminated
Data out input normal, check LED is illuminated
Dimmer override input
ON, check LED is illuminated
14.4.2 Panel Communications Check
Panel communications check verifies the inputs and outputs from the control panel to the A/ CCM.
To exit the panel communications check mode press the system ON button.
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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
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14.6 ACTUATOR CHECK
The system self test procedure drives all the actuator motors, to checktheir operation. If an actuator is operating incor- rectly or operating outside of its limits then a fault code will be present.
Before commencing with the actuator check procedure, ensure the car is operating under normal conditions.
Actuator Check Procedure
. Switch off the ignition.
. Press and hold the 'Auto' and 'Fresh / Recirc.' buttons simultaneously, and run the engine.
All the control panel LED's and all LCD segments will flash on and off. Any function LED indicator which does not
. Any LCD element which fails to flash on / off indicates a fault within the display element or panel.
. Press 'Auto'.
. Press 'Fresh / Recirc.' button to instigate actuator check mode.
. Use 'Face' to cycle through actuator mode conditions 20 to 27, as detailed in the table below.
flash
on
/ off suggests a fault condition within that area of the panel or, with the LED.
Press the 'Push Off button to restore normal operation with default panel settings, ie AUTO at 24OC.
1ynfe: * The water valve operates on a 6 second pulse, ie 3 seconds ON, 3 seconds OFF.
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DIAGNOSTIC TESTS 0 14.7 14.7.1 Fault Code 11
Motorized In-car Aspirator
The Motorized In-car Aspirator (MIA) comprises of a small motor and a thermistor.
o Thermistor, harness or A/ CCM open circuit.
0 Thermistor, harness or A/ CCM short circuit to ground.
The MIA operates in the range of
0 to 5 volts and forms the main reference point for the whole system.
If the signal on pin 33 (12-way connector, A/ CCM) 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 thermistor. If the signal on pin 33 rises to approximately 5 volts, suspect an open circuit on the earth supply to the thermistor.
Check the voltage, against the graph below (Fig.
I), measured between pin 33 (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 at the thermistor and should conform with the figures below, measured between
pin 1 and pin 2 (&way connector).
10°C 3.1
-3.7 w1 25°C 1.6- 1.8 lcrz
50°C 0.5 - 0.7 lcrz
0 If the resistance is outside the set limits, renew the thermistor.
14lnfe: The resistance should continue to decrease as the temperature increases and vice versa.
Inspect thermistor 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 operation of the motor can be checked by applying fused ignition feed to pin 3 and a ground to
pin 4, motor white,
4-way connector.
V
J66-1770
Fig. 1
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14.7.2 Fault Code 12
Ambient Temperature Sensor
0 Sensor, harness or A 1 CCM open circuit.
0 Sensor, harness or A 1 CCM short circuit to ground.
If the signal on pin 27 (12-way connector, AI CCM) 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 27 rises to approximately 5 volts, suspect an open circuit on the earth supply to the sensor.
Checkthe voltage, against the graph below (Fig. I), measured between pin 27 (12-way connector) and pin 19 (22-way
connector) A 1 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 27 (12-way connector) and pin 19 (22-way connector) AI CCM.
10°C 3.1
- 3.7 w1 25°C 1.6- 1.8 w1 50°C 0.5 - 0.7 w1
If the resistance is outside the set limits, renew the sensor.
Nnfe:
Inspect sensor harness for open circuit or short circuit to ground. Rectify as necessary.
If the voltage is outside the set limits, renew the AI CCM.
The resistance
should continue to decrease as the temperature increases and vice versa.
80
70
80
50
40
30
OC 20
10
0
-10
- 20
- 30
- 40
V
Fin. 1
J86 -17'38
0
0
0
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14.7.3 Faultcode 13
Evaporator Temperature Sensor
0 Sensor, harness or A / CCM open circuit.
0 Sensor, harness or A/ CCM short circuit to ground.
This sensor monitors the temperature of the evaporator matrix, the output is used to trigger the compressor circuit
via the
A/ CCM pin 34 (12-way connector).
If the signal on pin 34 (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 34 rises to approximately 5 volts
then suspect an open circuit on the sensor ground.
Checkthe voltage, against the graph below (Fig. I), measured between pin 34 (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 34 (12
-way connector) and pin 19 (22-way connector) A / C CM.
0°C
4.6- 5.1 WZ
15°C 2.1 - 2.6 WZ
If the resistance is outside the set limits, renew the sensor.
Note:
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
J86-1769
Fig. 1
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