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
14.2.16 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.
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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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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.
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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.
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rl Electrical
FAULT CODE 32
Driver-side Air Bag Circuit High Resistance or Open
Normal Operation
The DM monitors the resistance between pins 10 and 11. The value of this resistance is the sum of the two cable reel
cassettes, the air bag and is normally between
1.5~2 and 2Q. If the resistance measured exceeds 4Q the MIL Lamp will illuminate and fault code 32 will be present, indicating high resistance or open circuit on the air bag circuit.
Possible Causes
0 Poor connections or corrosion at clockspring / main harness connections.
0 Open circuit or high resistance of cable reel cassettes.
0 Open circuit or high resistance in driver-side air bag.
0 Faulty driver-side air bag wiring.
Fault Diagnosis
1. Circuit - check
. Disarm SRS system and disconnect DM.
Disconnect DM and remove plastic locking wedge from black DM harness connector.
. Measure resistance across harness connections to passenger air bag, wires KN and RF!
. Is resistance value less than 2Q ?
Yes -
. Ensure locking wedge has been removed correctly from black connector.
. Examine harness for broken, dirty or incorrectly seated connections.
. Rectify faults as necessary.
No - Proceed to step 2.
2. Resistance -check
. Is resistance measured in step 1 greater than 352 7
Yes - Proceed to step 4.
No - Proceed to step 3.
3. Fault code verification
. Reconnect DM and check if code 32 is still present.
Yes
- Renew DM.
No - Examine harness or broken, dirty or incorrectly seated connections. Rectify faults as necessary.
4. Resistance -check
. Disconnect cable reel cassette at base of steering column.
Install air bag simulator (ensure 2Q resistance of simulator before connection) in place of cable reel cassette.
Measure resistance across harness connections to air bag, wires KIN and RI?
Is resistance equal to between 1.m and 2.2Q 7
Yes - Renew cable reel cassette.
No - Examine harness wiring for open circuit, rectify faults as necessary.
5. On completion.
. Arm and verify the SRS system.
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