Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Manual Type 7B-7
Diagnostic Information and Procedures
A/C System Symptom DiagnosisS7RS0B7214001
ConditionPossible 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 “A/C Switch
Inspection”.
Blower speed selector faulty Check blower speed selector referring to
“Blower Speed Selector Inspection in Section
7A”.
Evaporator thermistor (Evaporator
temperature sensor) faulty Check evaporator thermistor (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.
ECM faulty Check ECM referring to “A/C System
Inspection at ECM”.
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”.
BCM faulty Check BCM referring to “Inspection of BCM
and its Circuits in Section 10B”.
No cool air comes out
(radiator cooling fan
motor does not operate) Fuse blown
Check related fuses, and then check for short
circuit to ground.
Wiring or grounding faulty Repair as necessary.
Radiator cooling fan motor relay faulty Check radiator cooling fan motor relay
referring to “Radiator Cooling Fan Relay
Inspection in Section 1F”.
Radiator cooling fan motor faulty Check radiator cooling fan motor referring to
“Radiator Cooling Fan Removal and
Installation in Section 1F”.
ECM and/or its circuit faulty Check ECM and/or its circuit referring to “A/C
System Inspection at ECM”.
No cool air comes out
(blower motor does not
operate) Fuse blown
Check related fuses, and then check for short
circuit to ground.
Blower motor relay faulty Check blower motor relay referring to “Blower
Motor Relay Inspection in Section 7A”.
Blower motor resistor faulty Check blower motor resistor referring to
“Blower Motor Resistor Inspection in Section
7A”.
Blower speed selector faulty Check blower speed selector referring to
“Blower Speed Selector Inspection in Section
7A”.
Wiring or grounding faulty Repair as necessary.
Blower motor faulty Check blower motor referring to “Blower Motor
Inspection in Section 7A”.
Downloaded from www.Manualslib.com manuals search engine 7B-8 Air Conditioning System: Manual Type
Cool air does not come
out or insufficient cooling
(A/C system normal
operation)Insufficient or excessive charge of
refrigerant
Check the amount of refrigerant and system
for leaks.
Condenser clogged Check condenser referring to “Condenser
Assembly On-Vehicle Inspection”.
A/C evaporator clogged or frosted Check A/C evaporator and evaporator
thermistor (evaporator temperature sensor)
referring to “Evaporator Inspection” and
“Evaporator Thermistor (Evaporator
Temperature Sensor) Inspection”.
Evaporator thermistor (Evaporator
temperature sensor) faulty Check evaporator thermistor (Evaporator
temperature sensor) referring to “Evaporator
Thermistor (Evaporator Temperature Sensor)
Inspection”.
Expansion valve faulty Check expansion valve referring to “Expansion
Valve Inspection”.
Desiccant clogged Replace receiver/dryer.
Compressor drive belt loosened or
broken Adjust or replace drive belt.
Magnet clutch faulty Check magnet clutch referring to “Magnet
Clutch Inspection”.
Compressor faulty Check compressor.
Air in A/C system Replace receiver/dryer, and then perform
evacuation and charge referring to “Operation
Procedure for Refrigerant Charge”.
Air leaking from HVAC unit or air duct Repair as necessary.
Heater and ventilation system faulty Check HVAC unit.
Blower motor faulty Check blower motor referring to “Blower Motor
Inspection in Section 7A”.
Excessive compressor oil in A/C system Drain excessive compressor oil from A/C
system circuit and compressor.
Cool air does not come
out only intermittently Wiring connection faulty
Repair as necessary.
Expansion valve faulty Check expansion valve referring to “Expansion
Valve Inspection”.
Excessive moisture in A/C system Replace receiver/dryer, and then perform
evacuation and charge referring to “Operation
Procedure for Refrigerant Charge”.
Magnet clutch faulty Check magnet clutch referring to “Magnet
Clutch Inspection”.
Excessive amount of refrigerant Check the amount of refrigerant.
Cool air comes out only
when driving vehicle at
high speed Condenser clogged
Check condenser referring to “Condenser
Assembly On-Vehicle Inspection”.
Insufficient charge of refrigerant Check the amount of refrigerant and system
for leaks.
Air in A/C system Replace receiver/dryer, and then perform
evacuation and charge referring to “Operation
Procedure for Refrigerant Charge”.
Compressor drive belt loosened or
broken Adjust or replace drive belt.
Compressor faulty Check compressor.
Cool air does not come
out only when driving
vehicle at high speed Excessive amount of refrigerant
Check the amount of refrigerant.
A/C evaporator frosted Check A/C evaporator and evaporator
thermistor (evaporator temperature sensor)
referring to “Evaporator Inspection” and
“Evaporator Thermistor (Evaporator
Temperature Sensor) Inspection”.
Condition Possible cause Correction / Reference Item
Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Manual Type 7B-9
Abnormal Noise Symptom Diagnosis of A/C SystemS7RS0B7214002
Abnormal Noise from Compressor
Abnormal Noise from Magnetic Clutch
Abnormal Noise from Tubing
Abnormal Noise from Condenser Assembly
Abnormal Noise from Crankshaft PulleyInsufficient airflow of
cooled air
A/C evaporator clogged or frosted
Check A/C evaporator and evaporator
thermistor (evaporator temperature sensor)
referring to “Evaporator Inspection” and
“Evaporator Thermistor (Evaporator
Temperature Sensor) Inspection”.
Air leaking from HVAC unit or air duct Repair as necessary.
Blower motor faulty Check blower motor referring to “Blower Motor
Inspection in Section 7A”.
Wiring or grounding faulty Repair as necessary.
Condition Possible cause Correction / Reference Item
Condition
Possible cause Correction / Reference Item
During compressor
operation, a rumbling
noise is heard
proportional to engine
revolutions Inadequate clearance in scroll area
Replace compressor.
A loud noise is heard at a
certain rpm,
disproportionately to
engine revolution Loose or faulty compressor drive belt
Adjust drive belt tension or replace drive belt.
Loose compressor mounting bolts Retighten mounting bolts.
A loud rattle is heard at
low engine rpm Loose compressor clutch plate bolt
Retighten clutch plate bolt.
Replace compressor if it was operated in this
condition for a long time.
Condition Possible cause Correction / Reference Item
A rumbling noise is heard
when compressor is not
in operation Worn or damaged bearings
Replace magnet clutch assembly.
A chattering noise is
heard when compressor
is in operation Faulty magnet clutch clearance
(excessive clearance)
Adjust magnet clutch clearance.
Worn magnet clutch friction surface Replace magnet clutch assembly.
Compressor oil leaked from shaft seal,
contaminating the friction surface Replace compressor body assembly.
Condition
Possible cause Correction / Reference Item
A droning noise is heard
from inside of the vehicle,
but not particularly
noticeable in engine
compartment Faulty tubing clamps
Reposition clamps or increase the number of
clamps.
Resonance caused by pulsation from
variations in re frigerant pressure Attach a silencer to tubing, or modify its
position and length.
Condition
Possible cause Correction / Reference Item
Considerable vibration in
condenser assembly Resonance from condenser assembly
bracket and body Firmly insert a silenc
er between condenser
assembly bracket and body.
Condition Possible cause Correction / Reference Item
A large rattling noise is
heard at idle or sudden
acceleration Loosen crankshaft pulley bolt
Retighten bolt.
Downloaded from www.Manualslib.com manuals search engine 7B-10 Air Conditioning System: Manual Type
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
Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Manual Type 7B-13
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
Downloaded from www.Manualslib.com manuals search engine 7B-18 Air Conditioning System: Manual Type
When replacing other parts
Replenish the following amount of oil to compressor.
Amount of compressor oil to be replenished
Evaporator: 25 cm3 (25 ml, 0.85 US. oz, 0.88 Imp. oz)
Condenser: 15 cm3 (15 ml, 0.51 US. oz, 0.53 Imp. oz)
Receiver/dryer: 10 cm3 (10 ml, 0.34 US. oz, 0.35 lmp.
oz)
Hoses: 10 cm
3 (10 ml, 0.34 US. oz, 0.35 Imp. oz) each
Pipes: 10 cm3 (10 ml, 0.34 US. oz, 0.35 Imp. oz) each
Evacuation
CAUTION!
Do not evacuate before recovering
refrigerant in A/C system.
NOTE
Once air conditioning system circuit is
opened (exposed) to atmospheric air, system
must be evacuated by using a vacuum pump.
The A/C system should be attached with a
manifold gauge set, and should be evacuated
for approximately 15 minutes.
1) Connect high charging hose (1) and low charging hose (2) of manifold gauge set (3) respectively as
follows:
High charging hose → High pressure charging valve
(4) on condenser outlet pipe
Low charging hose → Low pressure charging valve
(5) on suction pipe
2) Attach center charging hose (6) of manifold gauge set to vacuum pump (7).
3) Operate vacuum pump, and then open discharge
side valve (Hi) (8) of manifold gauge set.
If there is no blockage in the system, there will be an
indication on high pressure gauge (9).
In this case, open the other side valve (Lo) (10) of
the set and repair the system.
4) Approximately 10 minutes later, low pressure gauge (11) should show a vacuum lower than –100 kPa (–
1.0 kg/cm
2, –760 mmHg, –14.7 psi) providing no
leakage exists.
NOTE
• If the system does not show a vacuum below –100 kPa (–1.0 kg/cm
2, –760 mmHg,
–14.7 psi), close both valves, stop vacuum
pump and watch movement of low
pressure gauge.
• Increase in the gauge reading suggests existence of leakage. In this case, repair
the system before continuing its
evacuation.
• If the gauge shows a stable reading (suggesting no leakage), continue
evacuation.
5) Evacuation should be carried out for a total of at least 15 minutes.
6) Continue evacuation until low pressure gauge indicates a vacuum less than –100 kPa (–1.0 kg/cm
2,
–760 mmHg, –14.7 psi), and then close both valves.
7) Stop vacuum pump. Disconnect center charging hose from pump inlet. No w, the system is ready for
charging refrigerant.
Checking A/C System for Pressure Leaks
After completing the evacuation, close manifold gauge
high pressure valve and low pressure valve and wait 10
minutes. Verify that low pressure gauge reading has not
changed.
CAUTION!
If the gauge reading moves closer to “0”,
there is a leak somewhere. Inspect the tubing
connections and make necessary
corrections. And then, evacuate system once
again and make sure that there are no leaks.
7 5
2
4
1
10
11
3
9 8
6
I4RS0A720014-01
Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Manual Type 7B-19
Charge
CAUTION!
• Because the sight glass is not used for this A/C system, do not perform an additional
charge to the A/C system. To charge the
proper amount of refrigerant, recover and
evacuate the A/C system first. And then,
charge the proper amount of refrigerant
into the A/C system.
• Always charge refrigerant through low pressure side of A/C system after the initial
charge is performed from the high
pressure side with the engine stopped.
• Never charge refrigerant through high pressure side of A/C system with engine
running.
• Do not charge refrigerant while compressor is hot.
• When installing tap valve to refrigerant container to make a hole there through,
carefully follow dire ctions given by
manufacturer.
• A pressure gauge should always be used before and during refrigerant charge.
• The refrigerant container should be emptied of refrigerant when discarding it.
• The refrigerant container should not be heated up to 40 °C (104 °F) or over.
• Refrigerant container should not be reversed in direction during refrigerant
charge. Reversing in direction causes
liquid refrigerant to enter compressor,
causing troubles, such as compression of
liquid refrigerant and the like.
NOTE
The air conditioning system contains HFC-
134a (R-134a).
Described here is a method to charge the air
conditioning system with refrigerant from the
refrigerant service container.
When charging refrigerant recovered by
using the refrigerant and recycling
equipment (when recycling refrigerant),
follow the procedure described in the
equipment manufacturer’s instruction
manual.
Charge proper amount of refrigerant accurately in
accordance with the following procedure.
Specified amount of refrigerant
370 ± 20 g (13.0 ± 0.7 oz)
The initial charge of the A/C system is performed
through the high pressure side with the engine stopped.
And next, this method must be followed by charging from
the low pressure side with the engine running.
1) Check if hoses are routed properly after evacuating the system.
2) Connect low charging hose (1) and high charging hose (2) of the manifold gauge set (3) in position.
Then, open refrigerant container valve (4) to purge
the charging line.
3) Open the high pressure side valve (5) and charge refrigerant to system.
4) After a while, open the low pressure side valve (6) and close the high pressure side valve.
WARNING!
Make sure that high pressure side valve is
closed securely.
5) Start engine and keep engine speed at 1500 r/min, and then operate A/C system.
6) Charge A/C system with refrigerant in vapor state. At this time, refrigerant container should be held
upright.
1
2 6 3
5 4
I4RS0A720015-01
Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Manual Type 7B-21
Removal of Manifold Gauge Set
WARNING!
High pressure side is under high pressure.
Therefore, be careful not to get injured
especially on your eyes and skin.
For the A/C system charged with the specified amount of
refrigerant, remove manifold gauge set as follows:
1) Close low pressure side valve of manifold gauge set. (The high pressure side valve is closed continuously
during the process of charging.)
2) Close refrigerant container valve.
3) Stop engine.
4) Using shop rag, remove charging hoses from service valves. This operation must be performed quickly.
5) Put caps on service valves.
Check A/C System for Refrigerant Leaks
Whenever a refrigerant leak is suspected in the system
or any service operation has been performed which may
result in malfunction of lines and connections, it is
advisable to check for leaks.
Common sense should be used during refrigerant leak
test, since the need and extent of any such test will, in
general, depend upon the nature of a complaint and the
type of a service performed on the system.
Liquid leak detector
WARNING!
• To prevent explosions and fires, make sure that there are no flammables in the vicinity.
• When the refrigerant exposed to fire, it turns into a poisonous gas (phosgene). Do
not inhale this gas.
There is a number of fittings and places throughout the
A/C system where a liquid leak detector solution may be
used to pinpoint refrigerant leaks.
By merely applying the solution to the area in question
with a swab, such as attached to the cap of a vial,
bubbles will form within seconds if there is a leak.
For confined areas, such as sections of the evaporator
and condenser, an electronic (refrigerant) leak detector
is more practical fo r determining leaks.
Special tool
(A): 09990–86012
Condenser Assembly On-Vehicle InspectionS7RS0B7216002
Check the followings.
• Clog of condenser fins If any clog is found, cond enser fins should be washed
with water and should be dried with compressed air.
• Condenser fins for leakage and breakage If any defects are found, repair or replace condenser.
• Condenser fittings for leakage. If any defects are found, repair or replace condenser.
Condenser Assembly Removal and InstallationS7RS0B7216003
CAUTION!
Do not damage condenser fins. If condenser
fin is bent, straighten it by using flat head
screwdriver or pair of pliers.
Removal
1) Recover refrigerant from A/C system referring to “Operation Procedure for Refrigerant Charge”.
NOTE
The amount of removed compressor oil must
be measured for replenishing compressor
oil.
2) Remove front bumper referring to “Front Bumper and Rear Bumper Components in Section 9K”.
3) Disconnect discharge hose (1) and liquid pipe (2) from condenser assembly (3).
4) Remove condenser assembly mounting bolts (4).
(A)
I5RS0C721006-01
4
1
3
2
I4RS0A720017-01