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Abnormal Noise from Tension Pulley
Abnormal Noise from A/C Evaporator
Abnormal Noise from Blower Motor
A/C System Performance InspectionS7RS0B7214003
1) Confirm that vehicle and environmental conditions are as follows.
• Vehicle is put indoors.
• Ambient temperature is within 25 – 35 °C (77 – 95
° F).
• Relative humidity is within 30 – 70%.
• There is no wind indoors.
• HVAC unit is normal.
• Blower motor is normal.
• There is no air leakage from air ducts.
• Condenser fins are clean.
• Air filter in HVAC unit is not clogged with dirt and
dust.
• Battery voltage is about 12 V.
• Radiator cooling fan operates normally.
2) Make sure that high pressure valve (1) and low pressure valve (2) of manifold gauge are firmly
closed.
3) Connect high pressure charging hose (3) to high pressure service valve (5) on vehicle and low
pressure charging hose (4) to low pressure service
valve (6).
4) Bleed the air in charging hoses (3) and (4) by loosening their nuts respectively utilizing the
refrigerant pressure. When a hissing sound is heard,
immediately tighten nut.
CAUTION!
Do not connect high and low pressure
charging hoses in reverse.
Condition Possible cause Correction / Reference Item
Clattering noise is heard
from pulley Worn or damaged bearing
Replace tension pulley.
Pulley cranks upon
contact Cracked or loose bracket
Replace or retighten bracket.
ConditionPossible cause Correction / Reference Item
Whistling sound is heard
from A/C evaporator Depending on the combination of the
interior / exterior temperatures, engine
rpm and refrigerant pressure, the
refrigerant flowing out of the expansion
valve may, under certain conditions,
make a whistling sound At times, slightly decrea
sing refrigerant volume
may stop this noise.
Inspect expansion valve and replace if faulty.
Condition Possible cause Correction / Reference Item
Blower motor emits a
chirping sound in
proportion to its speed of
rotation Worn or damaged motor brushes or
commutator
Replace blower motor.
Fluttering noise or large
droning noise is heard
from blower motor Leaves or other debris introduced from
fresh air inlet to blower motor
Remove debris and make sure that the screen
at fresh air inlet is intact.
53
2
1
4 6
I4RS0A720006-01
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5) Warm up engine to the normal operating temperature and keep it at the specified idle speed.
6) Turn A/C switch ON, set blower speed selector at maximum speed position, temperature selector at
maximum cold position, airflow selector at face
position, and air intake switch at recirculation
position. (Confirm that A/C compressor and
condenser fans are working.)
7) Wait for ten minutes to stabilize the A/C operation.
8) Open front windows, front doors and engine hood.
9) With about 20 mm (0.8 in.) of dry bulb thermometer
(1) put right in front of center ventilation louver and a
wet and dry bulb thermometer (2) near air inlet of
HVAC unit. 10) Check for each pressure of low side and high side if
it is within shaded range of graph. If each gauge
reading is out of specified pressure, correct defective
part referring to the following table.
NOTE
Pressure registered on gauge varies with
ambient temperature. Therefore, use the
graphs when determining if pressures are
normal or not.
Low side and high side pressure example,
Gauges should read as follows when ambient
temperature is 30 °C (86 °F)
Pressure on high pressure gauge (HI): 1590 –
1940 kPa (15.9 – 19.4 kg/cm2)
Pressure on low pressure gauge (LO): 270 – 430
kPa (2.7 – 4.3 kg/cm
2)
2
1
I4RS0B720004-01
[A]: Pressure of high pressure gauge
[B]: Pressure of low pressure gauge
[C]: Ambient temperature
[D]: Humidity [E]: Acceptable range
22
312.9 2200
0 1
2 3 30 70 30 70 %
4 5 6 7 8 9
10
11 12 13 14 15
16 17
18
19 21
298.7 2100
20
14.2 28.4 42.7 56.9 71.1 85.3 99.5
113.8 128.0 142.2
151.4
170.6
184.9 199.1
213.3 227.5
241.7
256.0
270.2
284.4
100 200 300 400 500 600 700 800 900
1000 1100 1200
1300
1400 1500 1600
1700 1800
1900
2000
25 30 35
77 86 95
psi kPa kg/cm
2
C
F
“A”
“B”
“C”
“D”
23
2300
327.1
[A]
[B]
[C][D][E]
[E]
I7RS0A721006-01
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High pressure gauge
Low pressure gaugeCondition Possible cause Correction
Pressure is higher than
acceptable range
(“A” area) Refrigerant overcharged Recharge.
Expansion valve frozen or clogged Check expansion valve.
Clogged refrigerant passage of high pressure side Clean or replace.
Radiator cooling fan malfunction
(Insufficient cooling of condenser)
Check radiator cooling fan.
Dirty or bent condenser fins
(Insufficient cooling of condenser) Clean or repair.
Compressor malfunction (Insuffi cient oil etc.) Check compressor.
Engine overheat Check engine cooling system
referring to “Engin
e Cooling Symptom
Diagnosis in Section 1F”.
Pressure is lower than
acceptable range
(“B” area) Insufficient refrigerant
(Insufficient charge or leakage)
Check for leakage, repair if necessary
and recharge.
Expansion valve malfunction
(valve opens too wide) Check expansion valve.
Compressor malfunction
(Insufficient compression) Check compressor.
Condition Possible cause Correction
Pressure is higher than
acceptable range
(“C” area) Expansion valve malfunction
(valve opens too wide)
Check expansion valve.
Compressor malfunction
(Insufficient compression) Check compressor.
Pressure is lower than
acceptable range
(“D” area) Insufficient refrigerant
(Insufficient charge or leakage)
Check for leakage, repair if necessary
and recharge.
Expansion valve malfunction
(valve opens too narrow) Check expansion valve.
Clogged refrigerant passage (crashed pipe) Repair or replace.
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11) Check inlet port temperature-to-outlet port temperature relationship using the graph. For example, if temperature
near air inlet of HVAC unit is 30 °C (86 °F) and the one at air outlet of center ventilation louver is 17 °C (62.6 °F),
their crossing point is within acceptable range as shown in the graph. In this case, cooling performance is
satisfactory and proper.
12) If crossing point is out of acceptable range, diagnose trouble referring to the following table.
Thermometer at center duct
NOTE
If ambient temperature is approximately 30 °C (86 °F), it is possible to diagnose A/C system in detail
referring to the following table.
[A]: Temp at air outlet of center ventilation louver [C]: Humidity
[B]: Temp near air inlet of HVAC unit [D]: Acceptable range
ConditionPossible cause Correction
Crossing point is higher
than acceptable range
(“E” area) Insufficient or excessive charge of refrigerant Check refrigerant pressure.
Dirty or bent A/C evaporator fins
Clean or repair.
Air leakage from cooling (heater) unit or air duct Repair or replace.
Malfunctioning, switch over function of door in
cooling (heater) unit Repair or replace.
Compressor malfunct ion Check compressor.
Crossing point is lower
than acceptable range
(“F” area) Insufficient air volume from center duct
(Heater blower malfunction)
Check blower motor and fan.
Compressor malfunct ion Check compressor.
8 9
10 11 12 13 14
15 16 17 18 19
20
21
22
23
24
25 26
27
28
46.4 48.2 50.0 51.8 53.6 55.4 57.2 59.0 60.8 62.6 64.4
66.2 68.0
69.8
71.6
73.4
75.2
77.0
78.8 80.6
82.4
25 30 35
77 86 95
F C
C
F
“E”
“F”30 70 %
[A]
[B][C]
[D]
I7RS0A721007-01
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A/C System Inspection at ECMS7RS0B7214004
Voltage Check
When checking voltage at ECM connector terminals related to A/C system, refer to “DTC P2101: Throttle Actuator
Control Motor Circuit Range / Performance in Section 1A”.
0.40 – 0.45
(4.0 – 4.5)
(57 – 64)
2.0 – 2.5
(20 – 25)
(285 – 355) High pressure reading on
both low and high
pressure sides.
Overcharged A/C
system.
Adjust refrigerant to
specified amount.
Faulty condenser
cooling operation. Clean condenser.
Faulty radiator cooling
fan operation. Inspect and repair
radiator cooling fan.
High pressure reading on
both low and high
pressure sides.
Low pressure side tubing
is not cold when touched. Presence of air in A/C
system
(Improperly
evacuated).Replace receiver/
dryer.
Inspect quantity of
compressor oil and
presence of
contaminants in oil.
Evacuate system and
recharge with fresh
refrigerant.
0.45 – 0.55
(4.5 – 5.5)
(64 – 78) High pressure reading on
both low and high
pressure sides.
Large amount of frost or
dew on the low pressure
side tubing.Faulty expansion
valve.
Refrigerant flow is not
regulated properly.
Replace expansion
valve.
Condition
Possible cause Correction
Manifold gauge MPa (kg/cm
2) (psi)
Detail
Lo Hi
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Automatic Type
Precautions
A/C System CautionS7RS0B7220001
Refer to “A/C System Caution”.
Precautions in Diagnosing TroubleS7RS0B7220002
• Do not disconnect couplers from HVAC control module, battery cable from battery, HVAC control module ground
wire harness from body or main fuse before confirming diagnostic information (diagnostic trouble code) stored in
HVAC control module memory.
• Diagnostic information (diagnostic trouble code) stored in HVAC control module can be checked by display of HVAC
control module. Also, it can be checked by using SU ZUKI scan tool. Before checking diagnostic information
(diagnostic trouble code), read this manual and operator's manual for SUZUKI scan tool to know how to read
diagnostic information (diagnostic trouble code).
• When trouble is diagnosed using diagnostic information (diagnostic trouble code) on display of HVAC control
module, keep in your mind that each diagnostic inform ation (diagnostic trouble code) has priority, and only
diagnostic information (diagnostic troub le code) which has the highest priority is indicated. Therefore, after
troubleshooting the malfunction, make sure if there exists any other diagnostic information (diagnostic trouble
code).
• Be sure to read “Precautions for Electrical Circuit Service in Section 00” before inspection.
Precautions on Servicing A/C SystemS7RS0B7220003
Refer to “Precautions on Servicing A/C System”.
General Description
Auto A/C System DescriptionS7RS0B7221001
The automatic type air conditioning system (auto A/C) is pr ovided with the function to automatically control the inside
air temperature, fan speed, air flow outl et direction and air intake position by HVAC control module in addition to
functions of the manual type air conditioning system (manua l A/C). Once the inside air temperature is set using the
temperature selector, HVAC control module automatically controls the inside air temperature at the constant level at all
times based on the inside air temperature, outside ai r temperature, amount of sunlight and engine coolant
temperature detected respectively by the inside air te mperature sensor, outside air temperature sensor, sunload
sensor and ECT sensor. At this time, “FULL AUTO A/ C” appears on the display of HVAC control module.
With the air intake selector pushed in the above state, it is possible to select any position of the air intake actuator.
Then, “FULL AUTO A/C” on the display changes to “AUTO A/C”.
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Auto A/C Electronic Control Input / Output Table
HVAC Control Module Operation DescriptionS7RS0B7221002
Temperature Control
HVAC control module calculates the target temperature
control door position based on signals from the
temperature selector, inside air temperature sensor,
outside air temperature sensor and sunload sensor and
controls the temperature control actuator so that the
current position of the temperature control door matches
its target position.
Fan Speed Control
HVAC control module calculates the target blower fan
speed based on signals from the temperature selector,
inside air temperature sensor, outside air temperature
sensor and sunload sensor, compares it with the current
blower fan speed inputted from the blower motor
controller to control the current blower fan speed to the
target level.
Air Flow Outlet Control
HVAC control module calculates the target temperature
control door position based on signals from the
temperature selector, inside air temperature sensor,
outside air temperature sensor and sunload sensor.
Using thus obtained target temperature control door
position, it further calculates the target air flow control
door position and controls the ai r flow control actuator so
that the current air flow c ontrol door position becomes
the target position. Air Intake Position Control
HVAC control module determines the position of the air
intake control door based on signals from the
temperature selector, inside air temperature sensor,
outside air temperature sensor and sunload sensor and
selects any of the following positions by controlling the
position of the air intake control door.
• FRESH position (FRE)
• RECIRCULATION position (REC)
• MIX position (MIX)
Refrigerant Type IdentificationS7RS0B7221003
Refer to “Refrigerant Type Identification”.
Sub-Cool A/C System DescriptionS7RS0B7221005
Refer to “Sub-Cool A/C System Description”.
A/C Operation DescriptionS7RS0B7221006
Refer to “A/C Operation Description”.
Sunload sensor
Outside air temperature sensor Evaporator temperature sensor
A/C refrigerant pressure sensor
Temperature selector
MODE (air flow) selector
Blower speed selector
Air intake selector
AUTO switch
A/C switch
Compressor
Blower motor controller
Temperature control actuator
Air flow control actuator
Air intake control actuator
BCM
ECM
Data link connector
HVAC control module
CPU
ECT sensor
Inside air temperature sensor
VSS
*
I5RS0C722002-02
*: CAN communication
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Diagnostic Information and Procedures
A/C System Symptom DiagnosisS7RS0B7224001
4. Rear defogger relay 15. Evaporator temperature sensor 26. Radiator cooling fan relay No.1 37. Rear defogger switch
5. Rear defogger 16. Sunload sensor 27. Radiator cooling fan relay No.2 38. To BCM
6. Blower motor relay 17. Junction block assembly 28. Radiator cooling fan relay No.3 39. To ECM
7. Blower motor 18. ECM 29. Information display 40. To main relay
8. Blower motor controller 19. ECT sensor 30. Lighting switch 41. To main fuse
9. DLC 20. Radiator cooling fan motor 31. A/C switch 42. Back-light
10. Air intake actuator 21. Compressor relay 32. MODE (air flow) selector 43. Defroster indicator 11. Air flow control actuator 22. Compressor 33. Air intake selector 44. Rear defogger indicator
Condition Possible cause Correction / Reference Item
No cool air comes out (A/
C system does not
operate) No refrigerant
Perform recovery, evacuation and charge
referring to “Operation Procedure for
Refrigerant Charge”.
Fuse blown Check related fuses, and then check for short
circuit to ground.
A/C switch faulty Check A/C switch referring to “Inspection of
HVAC Control Module and Its Circuit”.
Evaporator temperature sensor faulty Check evaporator temperature sensor
referring to “Evaporator Thermistor
(Evaporator Temperature Sensor) Inspection”.
A/C refrigerant pressure sensor faulty Check A/C refrigerant pressure sensor
referring to “A/C Refrigerant Pressure Sensor
and Its Circuit Inspection”.
Wiring or grounding faulty Repair as necessary.
ECT sensor faulty Check ECT sensor referring to “ECT Sensor
Inspection in Section 1C”.
ECM faulty Check ECM referring to “A/C System
Inspection at ECM”.
HVAC control module faulty Check HVAC control module referring to
“Inspection of HVAC Control Module and Its
Circuit”.
Magnet clutch faulty Check magnet clutch. Referring to “Magnet
Clutch Inspection”.
Compressor drive belt loosened or
broken Adjust or replace drive belt.
Compressor faulty Check compressor.
Compressor relay faulty Check compressor relay referring to
“Compressor Relay Inspection”.
Temperature selector, blower speed
selector, and/or air flow selector faulty Check HVAC control module referring to
“Inspection of HVAC Control Module and Its
Circuit”.
BCM faulty Check BCM referring to “Inspection of BCM
and its Circuits in Section 10B”.