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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”.
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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.
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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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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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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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A/C Switch InspectionS7RS0B7216014
• Check that there is continuity between terminal (1) and terminal (2) when A/C s witch is at ON position.
• Check that there is no continuity between terminal (1) and terminal (2) when A/C s witch is at OFF position.
If check result does not meet the above conditions,
replace HVAC control unit.
Compressor Relay InspectionS7RS0B7216015
1) Disconnect negative (–) cable from battery.
2) Remove compressor relay (1) from main fuse box.
3) Check that there is no continuity between terminal “c” and “d”. If there is continuity, replace relay.
4) Connect battery positive (+ ) terminal to terminal “b”
of relay and battery negative (–) terminal to terminal
“a” of relay, and then check continuity between
terminal “c” and “d”. If there is no continuity, replace
relay.
Compressor Drive Belt Inspection and
Adjustment
S7RS0B7216016
Inspection
• Check compressor drive belt (1) for wear, crack, deformation and cleanliness. If any defect is found,
replace the belt with new one referring to
“Compressor Drive Belt Re moval and Installation”.
• Check compressor drive belt tension by measuring how much it deflects when pushed intermediate point
between magnet clutch pulley (6) and crankshaft
pulley (3) with about 100 N (10 kg) force after rotating
crankshaft pulley 360 °. If belt tension is out of
specification, adjust belt tension referring to
“Adjustment”.
Compressor drive belt tension
“a”
: 7 – 8mm (0.28 – 0.31 in.)
NOTE
When replacing drive belt, adjust drive belt
tension to the following specification.
New compressor dr ive belt tension “a”
: 6 – 7mm (0.24 – 0.28 in.)
Adjustment 1) Loosen tension pulley nut (4).
2) Adjust belt tension by ti ghten or loosen tension
pulley adjusting bolt (5).
3) Tighten tension pulley nut.
4) Rotate the crankshaft pulley 360 °, and then recheck
belt tension.
1 2
I4RS0B720013-01
"d"
"b" "a"
"c"
1
I4RS0B720014-01
2. Tension pulley
I4RS0A720033-01
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Compressor Drive Belt Removal and
Installation
S7RS0B7216017
Removal1) Loosen tension pulley nut (1).
2) Loosen belt tension by loosening tension pulley adjusting bolt (2).
3) Remove compressor drive belt (3).
Installation
Reverse removal procedure noting the following
instruction.
• Adjust belt tension referring to “Compressor Drive Belt Inspection and Adjustment”.
Compressor Assembly Removal and
Installation
S7RS0B7216018
Removal
1) Run engine at idle speed with A/C ON for 10 minutes.
2) Stop the engine.
3) Disconnect negative (–) cable from battery.
4) Recover refrigerant fr om the A/C system with
recovery and recycling equipment referring to
“Recovery” in “Operation Procedure for Refrigerant
Charge”.
5) Remove compressor drive belt referring to “Compressor Drive Belt Re moval and Installation”.
6) Remove right side engine under cover.
7) Disconnect magnet clutch lead wire coupler (1).
8) Disconnect discharge hose (2) and suction hose (3) from compressor (4).
NOTE
Cap open fittings immediately to keep
moisture out of the system.
9) Remove compressor mounting bolts (1), and then remove compressor (2 ) from its bracket.
Installation
Reverse removal procedure noting the following
instructions.
• If compressor is replaced, pour new compressor oil referring to “Replenishi ng Compressor Oil” in
“Operation Procedure for Refrigerant Charge”.
• Evacuate and charge the A/C system referring to “Evacuation” and “Charge” in “Operation Procedure
for Refrigerant Charge”.
• Adjust drive belt tension referring to “Compressor Drive Belt Inspecti on and Adjustment”.
I4RS0A720034-01
3
4 2
1
I7RS0A721009-01
1
1 2
I7RS0A721010-02