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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
Downloaded from www.Manualslib.com manuals search engine 7B-12 Air Conditioning System: Manual Type
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
Downloaded from www.Manualslib.com manuals search engine 7B-14 Air Conditioning System: Manual Type
ConditionPossible cause Correction
Manifold gauge MPa (kg/cm2) (psi)
Detail
Lo Hi
0.27 – 0.43
(2.7 – 4.3)
(38 – 61) 1.59 – 1.94
(15.9 – 19.4)
(226 – 276)
Normal condition — —
Negative pressure 0.5 – 0.6
(5 – 6)
(71.2 – 85.3) The low pressure side
reads a negative
pressure, and the high
pressure side reads an
extremely low pressure.
Presence of frost around
tubing to and from
receiver/dryer and
expansion valve. Dust particles or water
droplets are either
stuck or frozen inside
expansion valve,
preventing the
refrigerant from
flowing.Clean expansion
valve.
Replace it if it cannot
be cleaned.
Replace receiver/
dryer.
Evacuate the A/C
system and recharge
with fresh refrigerant.
Normal:
0.27 – 0.43
(2.7 – 4.3)
(38 – 61)
↑ ↓
Abnormal:
Negative pressure Normal:
1.59 – 1.94
(15.9 – 19.4)
(226 – 276)
↑
↓
Abnormal:
0.7 – 1.0
(7 – 10)
(100 – 142) During A/C operation, the
low pressure side
sometimes indicates
negative pressure, and
sometimes normal
pressure. Also high
pressure side reading
fluctuates between the
abnormal and normal
pressure.
Expansion valve is
frozen due to
moisture in the
system, and
temporarily shuts off
the refrigeration cycle.
Replace expansion
valve.
Replace receiver/
dryer.
Evacuate A/C system
and recharge with
fresh refrigerant.
0.05 – 0.15
(0.5 – 1.5)
(4.2 – 21.3) 0.7 – 1.0
(7 – 10)
(100 – 142) Both low and high
pressure sides indicate
low readings.
Output air is slightly cold.
Insufficient refrigerant
in system
(Refrigerant leaking).Using leak detector,
check for leaks and
repair as necessary.
Recharge refrigerant
to a specified amount.
If the pressure reading
is almost 0 when the
manifold gauges are
attached, check for
any leaks, repair
them, and evacuate
the system.
0.4 – 0.6
(4 – 6)
(56.9 – 85.3) Pressure on low pressure
side is high.
Pressure on high
pressure side is low.
Both pressure becoming
equal right after A/C is
turned OFF.
Internal leak in
compressor.
Inspect compressor
and repair or replace
as necessary.
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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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Repair Instructions
Operation Procedure for Refrigerant ChargeS7RS0B7216001
WARNING!
• Your eyes should not be exposed to refrigerant (liquid).Any liquid HFC-134a (R-134a) escaping by accident shows a temperature as low as approximately –
6 °C (21.2 ° F) below freezing point. Should liquid HFC-134a (R-134a) is exposed to your eyes, it may
cause a serious injury. To protect your eyes from such accident, it is necessary to always wear
goggles. Should it occur that HFC-134a (R-134a) is exposed to your eyes, consult a doctor
immediately.
– Do not use your hand to rub the affected eye(s). Instead, use fresh cold water to splash it over the affected area to gradually raise temperature of such area above freezing point.
– Obtain proper treatment as soon as possible from a doctor or eye specialist.
• Should the liquid refrigerant HFC-134a (R-134a) is exposed to your skin, the affected area should be treated in the same manner as when skin is frostbitten or frozen.
• Do not handle refrigerant near any place where welding or steam cleaning is performed.
• Refrigerant should be kept in a cold and dark pl ace. It should never be stored in any place where
temperature is high, e.g. where exposed to direct su n light, close to fire or inside vehicle (including
trunk room).
• Avoid breathing fume produced when HFC-134a (R-134a) is burned. Such fume may be hazardous to your health.
Recovery
When discharging refrigerant out of A/C system, always recover it by using refrigerant recovery and recycling
equipment because discharging refrigerant HFC-134a (R-1 34a) into atmosphere would cause adverse effect to
environments.
Start evacuation.Start evacuation.
Stop evacuation.Stop evacuation.
Wait 10 minutesWait 10 minutes
Check A/C system forCheck A/C system for
pressure tighteness.pressure tighteness.
Recharge A/C system withRecharge A/C system withrefrigerant.refrigerant.
Check A/C system for refrigerantCheck A/C system for refrigerantleaks and amount of refrigerantleaks and amount of refrigerantcharged.charged.
Performance testPerformance test
Inspect and repair connections.Inspect and repair connections.
If gauge showsIf gauge showsabnormal conditionsabnormal conditions
Recharge 370 20 g ofRecharge 370 20 g ofrefrigerant.refrigerant.
I5RS0C721005-01
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NOTE
• After recovering refrigerant from system, the amount of removed compressor oil must be measured
for replenishing compressor oil.
• When handling recovery and recycling equipment, be sure to follow the instruction manual for the equipment.
Replenishing Compressor Oil
It is necessary to replenish specified amount of
compressor oil to compressor from compressor suction
side hole (1) before evacuating and charging refrigerant.
When charging refrigerant only
When charging refrigerant without replacing any
component, replenish the same amount of measured oil
when recovering refrigerant (if not measure, replenish 10
cm
3 (10 ml, 0.34 US. oz, 0.35 Imp. oz) oil).
When replacing compressor
CAUTION!
Be sure to use specified compressor oil or an
equivalent compressor oil.
Compressor oil is sealed in each new compressor by the
amount required for A/C system. Therefore, when using
a new compressor, drain the calculated amount of oil
from it. “C” = “A” – “B”
“C”: Amount of oil to be drained
“A”: Amount of oil in a new compressor
“B”: Amount of oil in removed compressor
NOTE
Compressor assembly su
pplied from factory
is filled up with the following amount of oil.
: Compressor oil 99000–99015–00A
(MATSUSHITADENKI GU10)
Oil amount in compressor
90 ± 5 cm3 (90 ± 5 ml, 3.04 ± 0.17 US. oz, 3.17 ± 0.18
Imp. oz)
I4RS0A720012-01
1
I4RS0B720007-01
1. New compressor 2. Removed compressor
I2RH01720015-01
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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