climate control JAGUAR XJ6 1994 2.G Electrical Diagnostic Manual

Climate Control Systems
Minimum differential (Red)
Maximum differential (Blue)
14.7.8 Fault Code 23
Refrigerant Pressure Switch
(A / C vehicles only)
Test the refrigerant pressure switch and harness continuity between pin 17 (22-way connector) and pin 13 (22-way
connector) A / C CM.
If there are no continuity problems, renew the A / CCM.
If there is no continuity, test the continuity of the switch between black 2-way connector pin 2 and ground (pin 1). Switch should be closed circuit at a pressure of between 2 and 30 bar. If the switch is open circuit, suspect faulty switch
or incorrect gas charge.
If the switch is operating correctly. Inspect the switch harness for open circuit or short circuit to ground. Rectify as
necessary.
Nnfe: In ambient temperatures below O"C, 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. *
=8WZkIO%
=2 WZf 10%
1 4.7.9 Fault Code 24
Differential Potentiometer
Test the 5 volt supply to differential potentiometer between pin 1 and pin 2 (ground) at the potentiometer connector.
If there is no 5V supply, inspect the harness for open circuit or short circuit to ground.
If no harness faults are apparent,
renew the A / CCM.
1ynf9: The A / CCM provides a common 5V output and ground to all servos, ie all servo potentiometers are fed by a 5V rail. If all servos are inoperable check the A/ CCM outputs and harness, renew the A/ CCM.
Check resistance between pins 1 and
2, value should be IOWZ +10% at 20°C.
If the resistance measured falls outside the said limits, renew the potentiometer.
Check resistance between pins 1 and 3 at both maximum and minimum differential potentiometer positions; adjusted
via the variable differential control thumb wheel situated between dash centre face level vents.
Position
Closed
Open
Closed
Open
I Differential potentiometer position 1 Resistance 1
Action Value Test point
Recirc. lk2
Fresh 4k8 Pin 2 ground
Recirc. 4k8
Pin
1 +5volts Fresh 1 k2
If the resistance measured falls outside the said limits, renew the potentiometer.
a
0
0
Issue 1 August 1994 18 X300 EDM

Climate Control Systems
Position
Closed Open
Closed Open
14.7.11 Fault Code 32
RH Fresh / Recirc. Pofenfiomefer
Test the 5 volt supply to potentiometer between pin 1 and pin 2 (ground).
If there is no 5V supply, inspect the harness for open circuit or short circuit to ground. If no harness faults are apparent,
renew the A 1 CCM.
W: The A / CCM provides a common 5V output and ground to all servos, ie all servo potentiometers are fed by
a 5V rail. If all servos are inoperable check the A 1 CCM outputs and harness, renew the A I CCM.
Check resistance between potentiometer connector pins 1 and 2 at blower harness connector, value should be
6wl
f10% at 20°C.
Measure the resistance from the potentiometer wiper (pin
6) to pins 1 and 2 respectively. Resistances should read:
Action Value lest point
Recirc. 1 k2
Fresh 4k8 Pin 2 ground
R eci rc. 4k8
Pin 1 +5 volts
Fresh lk2
Closed Open
Closed
Open
e
I Position I Action I Valw 1 Test point I
High lk2
Low 4k8 Pin 2 ground
High 4k8
Pin
9 +5 volts
Low 1 k2
If the resistance measured falls outside the said limits, renew the potentiometer.
X300 EDM 19 Issue 1 August 1994

Climate Control Systems
Position
Closed
Open
Closed
ODen
14.7.13 Fault Code 34
Defrost
Vent Potentiomefer
Disconnect the CENTRE VENT servo yellow, Sway connector.
Test the 5V supply to the potentiometer at the air distribution connector (black 12-way), pin 9 (positive) and pin 2
If there is no 5 volt supply, inspect the harness for open circuit or short circuit to ground. If no harness faults are appar-
ent, renew the A / CCM.
&&: The A / CCM provides a common 5V output and ground to all servos, ie all servo potentiometers are fed by a 5V rail. If all servos are inoperable check the A/ CCM outputs and harness, renew the AI CCM.
Check resistance between potentiometer connector pins
9 and 2 at air distribution box connector (black 12-way), value
should be
6w1 +10% at 20°C.
Measure the resistance from the potentiometer wiper (pin
6) to pins 9 and 2 respectively. Resistances should read:
(ground).
Action Value Test
point
Defrost 4k8 Pin 2 ground
Feet 4k8
Pin 9 +5 volts
Defrost 1 k2
Feet
lk2
Position Action Value
Closed Feet
lk2
4k8
Open Face
Closed
Feet 4k8
Open Face
lk2
If the resistance measured falls outside the said limits, renew the potentiometer.
Test point
Pin 2 ground
Pin
9 +5 volts
14.7.14 Fault Code 35
Centre Vent Potentiometer
Disconnect the DEFROST VENT servo yellow, Sway connector.
Test the 5V supply to the potentiometer at the air distribution connector (black 12-way), pin 9 (positive) and pin 2
If there is no 5 volt supply, inspect the harness for open circuit or short circuit to ground. If no harness faults are appar- ent, renew the A/ CCM.
The
A / CCM provides a common 5V output and ground to all servos, ie all servo potentiometers are fed by
a 5V rail. If all servos are inoperable check the A/ CCM outputs and harness, renew the A / CCM.
Check resistance between potentiometerconnector pins
9 and 2 at air distribution box connector (black 12-way),value
should be 6wZ +10% at 20°C.
Measure the resistance from the potentiometer wiper (pin
3) to pins 9 and 2 respectively. Resistances should read:
(ground).
If the
resistance measured falls outside the said limits, renew the potentiometer.
Issue 1 August 1994 20 X300 EDM

Climate Control Systems
Position Action Value Test point
Closed Face 1 k2
Open Foot
4k8
Closed Face
4k8
Open Foot
1 k2
Pin 2 ground
Pin
9 +5 volts
14.7.15 Fault Code 36
Foot Vent
Potentiometer
Disconnect the COOL AIR BYPASS yellow, Sway connector.
. Test the 5V supply to the potentiometer at the main unit, pin 9 (positive) and pin 2 (ground).
If there is no 5 volt supply, inspect the harness for open circuit or short circuit to ground. If no harness faults are appar- ent, renew the A I CCM.
&&: The A I CCM provides a common 5V output and ground to all servos, ie all servo potentiometers are fed by a 5V rail. If all servos are inoperable check the A 1 CCM outputs and harness, renew the A 1 CCM.
Check resistance between potentiometer connector pins9 and
2 at blower motor connector, value should be 6kn +10%
at 20°C.
Measure the resistance from the potentiometer wiper (pin
6) to pins 9 and 2 respectively. Resistances should read:
14.7.16 Fault Code 4 1
1 H Fresh / Recirc. Motor
The resistance between pins 1 and 3, servo unit Sway connector, should read 4.8 - 7.2 kn.
If the resistance is outside of the set limits, renew the servo unit.
The motor operation can be checked by applying battery voltage to pin
5, motor %way connector, and ground to pin 4 of the connector. The motor arm should rotate smoothly in a clockwise direction. Renew the motor if the arm does
not rotate smoothly.
Apply battery voltage to pin
4, servo unit %ay connector, and ground to pin 5. The motor arm should rotate smoothly
in a anti-clockwise direction. Renew the motor if the arm does not rotate smoothly.
Inspect the harness for open circuit or short circuit to ground. Rectify as necessary.
If no harness faults are apparent,
renew the AI CCM.
14.7.17 Fault Code 42
RH Fresh / Recirc. Motor
The resistance between pins 1 and 3, servo unit Sway connector, should read 4.8 - 7.2 kn.
If the resistance is outside of the set limits, renew the servo unit.
The motor operation can be checked by applying battery voltage to pin
5, motor Sway connector, and ground to pin 4 of the connector. The motor arm should rotate smoothly in a clockwise direction. Renew the motor if the arm does
not rotate smoothly.
Apply battery voltage to pin
4, servo unit Sway connector, and ground to pin 5. The motor arm should rotate smoothly
in a anti-clockwise direction. Renew the motor if the arm does not rotate smoothly.
Inspect the harness for open circuit or short circuit to ground. Rectify as necessary.
If no harness faults are apparent,
renew the A I CCM.
21 Issue 1 August 1994

Climate Control Systems
14.7.18 Fault Code 43
Cool Air Bypass Servomotor
The resistance between pins 1 and 3, motor Sway connector, should read 4.8 - 7.2 WZ.
If the resistance is outside of the set limits, renew the motor.
The motor operation can be checked by applying battery voltage to pin
5, motor Sway connector, and ground to pin
4 of the connector. The motor arm should rotate smoothly in a clockwise direction. Renew the motor if the arm does
not rotate smoothly.
Apply battery voltage to pin
4, motor Sway connector, and ground to pin 5. The motor arm should rotate smoothly
in a anti-clockwise direction. Renew the motor if the arm does not rotate smoothly.
Inspect the harness for open circuit or short circuit to ground. Rectify as necessary.
If no harness faults are apparent,
renew the AI CCM.
14.7.19 Fault Code 44
Servomotor
- Defrost
The resistance between pins 1 and 3, motor Sway connector, should read 4.8 - 7.2 kQ.
If the resistance is outside of the set limits, renew the motor.
The motor operation can be checked by applying battery voltage to pin
5, motor Sway connector, and ground to pin 4 of the connector. The motor arm should rotate smoothly in a clockwise direction. Renew the motor if the arm does
not rotate smoothly.
Apply battery voltage to pin
4, motor Sway connector, and ground to pin 5. The motor arm should rotate smoothly
in a anti-clockwise direction. Renew the motor if the arm does not rotate smoothly.
inspect the harness for open circuit or short circuit to ground. Rectify as necessary.
If no harness faults are apparent,
renew the A I CCM.
14.7.20 Fault Code 45
Servomotor
- Face
The resistance between pins 1 and 3, motor &way connector, should read 4.8 - 7.2 WZ.
If the resistance is outside of the set limits, renew the motor.
The motor operation can be checked by applying battery voltage to pin
5, motor Sway connector, and ground to pin 4 of the connector. The motor arm should rotate smoothly in a clockwise direction. Renew the motor if the arm does
not rotate smoothly.
Apply battery voltage to pin
4, motor 5-way connector, and ground to pin 5. The motor arm should rotate smoothly
in a anti-clockwise direction. Renew the motor if the arm does not rotate smoothly.
Inspect the harness for open circuit or short circuit to ground. Rectify as necessary.
If no harness faults are apparent,
renew the AI CCM.
14.7.21 Fault Code 46
Servomotor
- Foot
The resistance between pins 1 and 3, motor Sway connector, should read 4.8 - 7.2 WZ.
If the resistance is outside of the set limits, renew the motor.
The motor operation can be checked by applying battery voltage to pin
5, motor Sway connector, and ground to pin 4 of the connector. The motor arm should rotate smoothly in a clockwise direction. Renew the motor if the arm does
not rotate smoothly.
Apply battery voltage to pin
4, motor Sway connector, and ground to pin 5. The motor arm should rotate smoothly
in a anti-clockwise direction. Renew the motor if the arm does not rotate smoothly.
Inspect the harness for open circuit or short circuit to ground. Rectify as necessary.
If no harness faults are apparent,
renew the AI CCM.
0
0
0
Issue 1 August 1994 22 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

Climate Control Systems r
High speed only - RH blower
Cause:
1. Faulty harness wiring.
2. Faulty power transmitter.
Remedy:
1. Check continuity of wiring harness between: blower motor pin 8 and ground. Pin 10 and A / CCM pin 42 (16-way connector). Pin 13 and A/ CCM pin 41 (16-way connector).
2. Check that voltage between pin 3 and ground varies with operation of fan speed control. Renew power transistor
if correct results not achieved.
High speed only - 1 H blower
Cause:
1. Faulty harness wiring.
2. Faulty power transmitter.
Remedy:
1.
2.
Check continuity of wiring harness between: Blower motor pin 8 and ground. Pin 10 and A/ CCM pin 49
(16-way connector). Pin 13 and A/ CCM pin 50 (16-way connector).
Check that voltage between pin 3 and ground varies with operation of fan speed control. Renew power transistor
if correct results not achieved.
Non functional high speed - RH blower
Cause:
1. Faulty high speed relay.
2. Faulty harness wiring.
Remedy:
1. Ensure correct seating of relay on base, examine pins for damage or deformity.
Ensure 12V supply relay pin
5 and ground.
Ensure continuity between relay pins 3 and
5 when the relay is operated.
Ensure relay impedance of
7552 to 13552 of across pins 1 and 2.
2.
Check continuity of wiring from relay pin 2 to A/ CCM pin 64 (26-way connector).
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).
Non functional high speed - LH blower
Cause:
1. Faulty high speed relay.
2. Faulty harness wiring.
Remedy:
1. Ensure
correct seating of relay on base, examine pins for damage or deformity.
Ensure
12V supply relay pin 5 and ground.
Ensure continuity between relay pins 3 and
5 when the relay is operated.
Ensure relay impedance of
7552 to 13552 of across pins 1 and 2.
2. Check continuity of wiring from relay pin 2 to A/ CCM pin 65 (26-way connector).
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).
Issue 1 August 1994 24 X300 EDM

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