Downloaded from www.Manualslib.com manuals search engine 7-ii Table of Contents
Recommended Service Material ....................... 7B-33
Special Tool ...................................................... 7B-33
Automatic Type .................... .................................7B-34
Precautions.........................................................7B-34 A/C System Caution .......................................... 7B-34
Precautions in Diagnosing Trouble ................... 7B-34
Precautions on Servicing A/C System .............. 7B-34
General Description .......... .................................7B-34
Auto A/C System Descript ion ............................ 7B-34
HVAC Control Module Operation Description ... 7B-36
Refrigerant Type Identifica tion .......................... 7B-36
Sub-Cool A/C System Description .................... 7B-36
A/C Operation Description ................................ 7B-36
On-Board Diagnostic System Description ......... 7B-37
Schematic and Routing Diagram ......................7B-37 Major Components of A/C System .................... 7B-37
A/C System Wiring Diagra m ............................. 7B-38
Diagnostic Information and Procedures ..........7B-39 A/C System Symptom Diagnosis ...................... 7B-39
Abnormal Noise Sympto m Diagnosis of A/C
System ............................................................ 7B-42
DTC Check........................................................ 7B-42
DTC Clearance ................................................. 7B-43
DTC Table ......................................................... 7B-44
Fail-Safe Table ................. ................................. 7B-45
Scan Tool Data ................................................. 7B-46
Air Conditioning System Check......................... 7B-47
Visual Inspection ............................................... 7B-49
DTC B1502: Inside Air Temperature Sensor and/or Its Circuit Malfunction .......................... 7B-49
DTC B1503: A/C Evaporator Air Temperature Sensor and/or Its Circuit Malfunction .............. 7B-50
DTC B1504: Sunload Sensor and/or Its Circuit Malfunction ......... ................................. 7B-52
DTC B1511: Temperature Control Actuator (Position Sensor) and/or Its Circuit
Malfunction ...................................................... 7B-53
DTC B1512: Air flow Control Actuator (Position Sensor) and/or Its Circuit
Malfunction ...................................................... 7B-55
DTC B1513: Temperature Control Actuator and/or Its Circuit Malfunction .......................... 7B-57
DTC B1514: Air Flow Co ntrol Actuator and/or
Its Circuit Malfunction ...................................... 7B-60
DTC B1541: HVAC Control Module Back-Up Power Supply Malfunction .............................. 7B-62
DTC B1546: A/C Refrigerant Pressure Malfunction ...................................................... 7B-63
DTC B1551: Serial Communication Circuit Malfunction ...................................................... 7B-63
DTC B1552: Serial Communication Signal Malfunction ...................................................... 7B-64
DTC B1553: CAN Communication Signal Malfunction ...................................................... 7B-65
DTC B1557: Vehicle Speed Sensor Signal Malfunction ...................................................... 7B-65
DTC B1561: Engine Coolant Temperature Sensor Signal Malfunctio n .............................. 7B-66 DTC B1562: Outside Air Temperature Sensor
Signal Malfunction ........................................... 7B-66
DTC B1563: A/C Refr igerant Pressure
Sensor Signal Malfunction .............................. 7B-66
Inspection of HVAC Control Module and Its Circuit .............................................................. 7B-67
A/C System Performance Inspection ................ 7B-70
A/C System Inspection at ECM ......................... 7B-70
Repair Instructions ............ ................................7B-71
Operation Procedure for Refrigerant Charge .... 7B-71
HVAC Unit Components ................................... 7B-72
HVAC Unit Removal and In stallation ................ 7B-73
Temperature Control Actuator Removal and Installation ....................................................... 7B-73
Temperature Control Actuat or Inspection ......... 7B-73
Air Flow Control Actuator Removal and Installation ....................................................... 7B-74
Air Flow Control Actuator Inspection ................. 7B-74
Air Intake Control Actuator Removal and Installation ....................................................... 7B-75
Air Intake Control Actuator Inspection............... 7B-75
Actuator Linkage Inspection .............................. 7B-76
Blower Motor Controller Removal and Installation ....................................................... 7B-76
Blower Motor Controller Inspection ................... 7B-76
HVAC Control Module Removal and Installation ....................................................... 7B-77
Sunload Sensor Removal and Installation ........ 7B-77
Sunload Sensor Inspection ............................... 7B-77
Outside Air Temperature Sensor Removal and Installation ................................................ 7B-77
Outside Air Temperature Sensor Inspection ..... 7B-77
Inside Air Temperature Sensor Removal and Installation ....................................................... 7B-78
Inside Air Temperature Sens or Inspection ........ 7B-78
Condenser Assembly On-Vehicle Inspection .... 7B-78
Condenser Assembly Removal and Installation ....................................................... 7B-78
Receiver/Dryer Removal and Installation .......... 7B-78
Evaporator Inspection ....................................... 7B-78
Evaporator Temperature Sensor Removal and Installation ................................................ 7B-78
Evaporator Temperature Se nsor Inspection ..... 7B-78
Expansion Valve Removal an d Installation ....... 7B-78
Expansion Valve Inspection .............................. 7B-78
A/C Refrigerant Pressure Sensor and Its Circuit Inspection............................................. 7B-78
A/C Refrigerant Pressu re Sensor Removal
and Installation ................................................ 7B-78
Compressor Relay Inspection .
.......................... 7B-78
Compressor Drive Belt Inspection and Adjustment ...................................................... 7B-78
Compressor Drive Belt Removal and Installation ....................................................... 7B-79
Compressor Assembly Removal and Installation ....................................................... 7B-79
Compressor Assembly Components................. 7B-79
Magnet Clutch Removal and Installation........... 7B-79
Magnet Clutch Inspection.................................. 7B-79
Relief Valve Inspection...................................... 7B-79
Downloaded from www.Manualslib.com manuals search engine 7B-2 Air Conditioning System: Manual Type
Refrigerant Line
• Never use heat for bending pipes. When bending a pipe , try to make its bending angle as smooth as possible.
• Keep internal parts of air conditioning free from moistu re and dirt. When disconnecting any line from system, install
a blind plug or cap to the fitting immediately.
• When connecting hoses and pipes, apply a few drops of compressor oil (refrigerant oil) to O-ring.
• When tightening or loosening a fitting, use two wrenches, one for turning and the other for support.
• When handling recovery and recycling equipment, be sure to follow the instruction manual for the equipment.
• Check local governmental regulations regarding working with refrigerator systems and its tooling.
• Route drain hose so that drained water does not make any contact to vehicle components.
• If pipes or hoses are replaced, replenish specified amount of compressor oil to compre ssor suction side referring to
“Replenishing Compressor Oil” in “Operation Procedure for Refrigerant Charge”.
Refrigerant 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.
NOTE
When handling recovery and recycling equipment, be sure to follow the instruction manual for the
equipment.
Refrigerant Charge
After performing compressor oil replenishment and evacuat ion, charge a proper amount of refrigerant to A/C system
referring to “Charge” in “Operation Procedure for Refrigerant Charge”.
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1. Suction hose : Apply compressor oil (refrigerant oil) to O-ring. 4. Expansion valve
: Apply compressor oil (refrigerant oil) to O-ring.
2. Discharge hose : Apply compressor oil (refrigerant oil) to O-ring. 5. A/C refrigerant pressure sensor
: Apply compressor oil (refrigerant oil) to O-ring.
3. Liquid pipe : Apply compressor oil (refrigerant oil) to O-ring.
Downloaded from www.Manualslib.com manuals search engine 7B-4 Air Conditioning System: Manual Type
Sub-Cool A/C System DescriptionS7RS0B7211003
In the sub-cool A/C system (condenser integrated with receiver/dryer), the inside of the condenser is divided into the
condensation part and the sub-cooler part, and the receiver/dryer is located between those. In the receiver/dryer, the
refrigerant is separated into the vapor refrigerant and the liqui d refrigerant. Only the liquid refrigerant is delivered to the
sub-cooler part of the condenser. The refrigerant is supercooled by the sub-cooler part of the condenser.
A/C Operation DescriptionS7RS0B7211004
ECM controls the radiator fan relay and the compressor relay by following signals.
• ON/OFF signal of A/C switch
• A/C refrigerant pressure sensor
• Evaporator thermistor (evaporator temperature sensor)
• ECT sensor
NOTE
The signal of A/C swit ch is fed from BCM to ECM usin g CAN communication system. For CAN
communication system, refer to “CAN Communication System Description in Section 1A”.
I7RS0A721001-01
[A]: Liquid 2. Magnet clutch 6. Expansion valve10. Desiccant
[B]: Vapor 3. Condenser 7. A/C evaporator11. Filter
[C]: Superheated vapor 4. Receiver/dryer (Modulator) 8. Condensation part12. Vapor refrigerant
1. Compressor 5. Refrigerant pressure sensor 9. Sub-cooler part 13. Liquid refrigerant
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.
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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.
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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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.
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I4RS0A720014-01