HAC-10
< SYSTEM DESCRIPTION >[AUTOMATIC AIR CONDITIONER]
COMPONENT PARTS
Component Description
INFOID:0000000009463092
1. ECM 2. IPDM E/R 3. BCM (view with combination meter removed)
4. A/C auto amp. (view with A/C switch assembly removed) 5. A/C switch assembly 6. A/C Compressor
7. Sunload sensor 8. Refrigerant pressure sensor (view with front bumper fascia removed)9. Ambient sensor
10. Fuse Block (J/B), Front blower motor relay 11. In-vehicle sensor 12. Accessory relay-2 (view with instru-
ment panel removed)
13. Blower motor (view with front A/C as- sembly removed from vehicle) 14. Intake door motor 15. Mode door motor
16. Air mix door motor LH 17. Air mix door motor RH 18. Intake sensor
ALIIA0599ZZ
Component Description
A/C auto amp. A/C auto amp. controls front automatic air conditioning system by inputting and calculating signals
from each sensor and each switch.
A/C Compressor Vaporized refrigerant is drawn into the A/C compressor from the evaporator, where it is compressed
to a high pressure, high temperature vapor. The hot, compressed vapor is then discharged to the con-
denser.
A/C switch assembly The A/C switch assembly controls the operation of the A/C and heating system based on inputs from
the temperature control knob, the mode switches, the blower control dial, the ambient temperature
sensor, the intake sensor, and inputs received from the ECM across the CAN. Diagnosis of the A/C
switch assembly can be performed using the CONSULT. There is no self-diagnostic feature available.
Air mix door motor LH The air mix door controls the mix of hot or cold air that enters the ventilation system. It is controlled
by the A/C auto amp. based on the position of the temperature dial. The air mix door motor LH re-
ceives position commands from the A/C auto amp. and reports actual door position back via an LCU
(Local Control Unit) installed inside the motor. Commands and responses are sent across the LIN (Lo-
cal Interconnect Network) to each motor simultaneously, with each motor having its own unique ad-
dress, thereby only responding to requests sent to its specific address. The LCU reads the door
position from a Position Balanced Resistor (PBR), also part of the motor, and returns that information
to the A/C auto amp. The LCU switches the polarity of the circuits connected to the DC motor to drive
the motor forward or backward as requested by the A/C auto amp. If the air mix door moves to a po-
sition less than 5% or more than 95% of its expected or allowed positions, the A/C auto amp. will set
a DTC.
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COMPONENT PARTSHAC-11
< SYSTEM DESCRIPTION > [AUTOMATIC AIR CONDITIONER]
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Air mix door motor RH The air mix door controls the mix of hot or cold air that enters the ventilation system. It is controlled
by the A/C auto amp. based on the position of the temperature dial. The air mix door motor RH re-
ceives position commands from the A/C auto amp. and reports actual door position back via an LCU
(Local Control Unit) installed inside the motor. Commands and responses are sent across the LIN (Lo-
cal Interconnect Network) to each motor simultaneously, with each motor having its own unique ad-
dress, thereby only responding to requests sent to its specific address. The LCU reads the door
position from a Position Balanced Resistor (PBR), also part of the motor, and returns that information
to the A/C auto amp. The LCU switches the polarity of the circuits connected to the DC motor to drive
the motor forward or backward as requested by the A/C auto amp. If the air mix door moves to a po-
sition less than 5% or more than 95% of its expected or allowed positions, the A/C auto amp. will set
a DTC.
Ambient sensor The ambient sensor measures the temperature of the air surrounding the vehicle. The sensor uses a
thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor
decreases as temperature increases.
BCM The BCM receives the fan ON and A/C ON signals from the A/C auto amp. and sends a compressor
ON request to the ECM.
Blower motor The blower motor varies the speed at which the air flows through the ventilation system.
ECM The ECM sends a compressor ON request to the IPDM E/R based on the status of engine operation
and load as well as refrigerant pressure information. If all the conditions are met for A/C operation,
the ECM transmits the compressor ON request to the IPDM E/R. The ECM shares the refrigerant
pressure sensor signal, engine RPM, and engine coolant temperature with the A/C auto amp. via
CAN communication line.
Front blower motor relay The front blower motor relay controls the flow of current to fuse 17 and 27 in the Fuse Block (J/B).
The relay is connected directly to ground, and is energized when the ignition switch is in the ON or
START position.
Fuse Block (J/B) Located in the passenger compartment, behind the left lower IP, the Fuse Block (J/B) contains the
front blower motor relay and several fuses required for the air conditioner control system.
Intake door motor The intake door motor controls the position of the intake door. Fresh air is allowed to enter the cabin
in one position, and recirculated inside air is allowed to enter in the other position. At times the A/C
auto amp. may command partial fresh or recirculation based on evaporator or coolant temperatures.
The intake door motor receives position commands from the A/C auto amp. and reports actual door
position back via an LCU (Local Control Unit) installed inside the motor. Commands and responses
are sent across the LIN (Local Interconnect Network) to each motor simultaneously, with each motor
having its own unique address, thereby only responding to requests sent to its specific address. The
LCU reads the door position from a Position Balanced Resistor (PBR), also part of the motor, and re-
turns that information to the A/C auto amp. The LCU switches the polarity of the circuits connected to
the DC motor to drive the motor forward or backward as requested by the A/C auto amp. If the recir-
culation door moves to a position less than 5% or more than 95% of its expected or allowed positions,
the A/C auto amp. will set a DTC.
Intake sensor The intake sensor measures the temperature of the front evaporator fins. The sensor uses a ther-
mistor which is sensitive to the change in temperature. The electrical resistance of the thermistor de-
creases as temperature increases.
In-vehicle sensor In-vehicle sensor measures temperature of intake air that flows through aspirator to passenger room.
The sensor uses a thermistor which is sensitive to the change in temperature. The electrical resis-
tance of the thermistor decreases as temperature increases.
IPDM E/R Refer to PCS-6, "RELAY CONTROL SYSTEM : System Description"
.
Mode door motor The mode door controls the direction the conditioned air passes through the ventilation system.
Through a series of levers and gears, the mode door controls the defrost door, the foot door, and the
vent door. There are 5 preset positions: VENT, B/L, FOOT, D/F, and DEF. The FOOT position can be
set to allow some airflow through to the defroster vent, or to completely block the defroster vent using
the CONSULT. The mode door motor receives position commands from the A/C auto amp. and re-
ports actual door position back via an LCU (Local Control Unit) installed inside the motor. Commands
and responses are sent across the LIN (Local Interconnect Network) to each motor simultaneously,
with each motor having its own unique address, thereby only responding to requests sent to its spe-
cific address. The LCU reads the door position from a Position Balanced Resistor (PBR), also part of
the motor, and returns that information to the A/C auto amp. The LCU switches the polarity of the cir-
cuits connected to the DC motor to drive the motor forward or backward as requested by the A/C auto
amp. The mode door has 5 expected positions and, therefore, can set up to 5 DTCs if the expected
position is not reported back to the A/C auto amp.
Component Description
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HAC-12
< SYSTEM DESCRIPTION >[AUTOMATIC AIR CONDITIONER]
COMPONENT PARTS
Refrigerant pressure sensorRefer to
EC-36, "Refrigerant Pressure Sensor" for QR25DE and EC-562, "Refrigerant Pressure Sen-
sor" for VQ35DE.
Sunload sensor Sunload sensor measures sunload amount. This sensor is a dual system so that sunload for driver
side and passenger side are measured separately. This sensor converts sunload amount to voltage
signal by photodiode and transmits to A/C auto amp.
Component Description
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HAC-16
< SYSTEM DESCRIPTION >[AUTOMATIC AIR CONDITIONER]
SYSTEM
Air Outlet Control
INFOID:0000000009463097
• While air outlet is in automatic control, A/C auto amp. selects the mode door position depending on a target air mix door angle and
outlet air temperature calculated from sunload.
• If ambient temperature is excessively low, D/F is selected to pre- vent windshield fogging when air outlet is set to FOOT.
Compressor ControlINFOID:0000000009463098
DESCRIPTION
• When the compressor activation condition is satisfied whil e blower motor is activated, A/C auto amp. trans-
mits A/C ON signal and blower fan ON signal to ECM via CAN communication.
• ECM judges that the compressor can be activated depending on the state of each sensor (refrigerant pres-
sure sensor signal and others) and transmits A/C comp ressor request signal to IPDM E/R via CAN commu-
nication.
• IPDM E/R turns A/C relay ON and activate s the compressor depending on request from ECM.
COMPRESSOR PROTECTION CONTROL AT PRESSURE MALFUNCTION
When high-pressure side value that is detected by refrigerant pressure sensor is as per the following state,
ECM requests IPDM E/R to turn A/C relay OFF and stops the compressor.
• 3.12 MPa (31.82 kg/cm
2, 452.4 psi) or more (When the engine speed is less than 1,500 rpm)
• 2.74 MPa (27.95 kg/cm
2, 397.3 psi) or more (When the engine speed is 1,500 rpm or more)
• 0.14 MPa (1.43 kg/cm
2, 20.3 psi) or less
COMPRESSOR OIL CIRCULATION CONTROL
When the engine starts while the engine coolant temperature is 56 °C (133 °F) or less, ECM activates the com-
pressor for approximately 6 seconds and circulates the compressor lubricant once.
LOW TEMPERATURE PROTECTION CONTROL
• When intake sensor detects that front evaporator fin temperature is 2.5 °C (37 °F) or less, A/C auto amp. requests ECM to turn com-
pressor OFF, and stops the compressor.
• When the front evaporator fin temperature returns to 5.0 °C (41 °F)
or more, the compressor is activated.
OPERATING RATE CONTROL
When set temperature is other than fully cold or air out let is “VENT”, “B/L” or “FOOT” A/C auto amp. controls
the compressor activation depending on ambient temperature.
AIR CONDITIONING CUT CONTROL
When set engine is running is excessively high load conditi on, ECM requests IPDM E/R to turn A/C relay OFF,
and stops the compressor. Refer to EC-56, "AIR CONDITIONING CUT CONT ROL : System Description (with
automatic air conditioner)" (QR25DE) or EC-573, "AIR CONDITIONING CUT CONTROL : System Descrip-
tion" (VQ35DE) for details.
JMIIA0730GB
JMIIA0742GB
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HAC-94
< SYMPTOM DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
HEATER AND AIR CONDITIONING
SYSTEM CONTROL SYMPTOMS
SYMPTOM DIAGNOSIS
HEATER AND AIR CONDITIONING SYSTEM CONTROL SYMPTOMS
Diagnosis Chart By SymptomINFOID:0000000009463166
NOTE:
Perform the self-diagnoses with CONSULT before perfo rming the symptom diagnosis. If DTC is detected, per-
form the corresponding diagnosis.
Symptom Corresponding malfunction part Reference
• Air conditioning does not activate.
• Air conditioning cannot be controlled.
• Operation status of air conditioning is not indicated on display. • A/C auto amp. ignition power supply
circuit
• Front A/C control (A/C auto amp.) HAC-78, "A/C AUTO AMP. : Diag-
nosis Procedure"
• Air outlet does not change.
• Mode door motor does not operate normally. • Circuit between mode door motor
and A/C auto amp.
• Mode door motor control linkage
• Mode door motor
• A/C auto amp. HAC-80, "MODE DOOR MOTOR :
Diagnosis Procedure"
• Discharge air temperature of driver side does not
change.
• Air mix door motor LH does not operate normally. • Circuit between air mix door motor
LH and A/C auto amp.
• Air mix door motor LH installation condition
• Air mix door motor LH
• A/C auto amp. HAC-78, "AIR MIX DOOR MOTOR
(DRIVER SIDE) : Diagnosis Proce-
dure"
• Discharge air temperature of passenger side does
not change.
• Air mix door motor RH does not operate normally. • Circuit between air mix door motor
RH and A/C auto amp.
• Air mix door motor RH installation condition
• Air mix door motor RH
• A/C auto amp. HAC-79, "AIR MIX DOOR MOTOR
(PASSENGER SIDE) : Diagnosis
Procedure"
• Intake door does not change.
• Intake door motor does not operate normally. • Circuit between intake door motor
and A/C auto amp.
• Intake door motor control linkage
• Intake door motor
• A/C auto amp. HAC-81, "INTAKE DOOR MOTOR :
Diagnosis Procedure"
All door motors do not operate normally.
• Each door motor power supply and
ground circuit
• A/C auto amp. HAC-89, "Diagnosis Procedure"
Blower motor operation is malfunctioning. • Power supply system of front blower
motor
• Circuit between front blower motor
and A/C auto amp.
• Front blower motor
• A/C auto amp. HAC-84, "Diagnosis Procedure"
Compressor does not operate. • Circuit between magnet clutch and
IPDM E/R
• Magnet clutch
• IPDM E/R (A/C relay)
• Circuit between ECM and refriger- ant pressure sensor
• Refrigerant pressure sensor
• CAN communication circuit
• A/C auto amp. HAC-87, "Diagnosis Procedure"
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HAC-96
< SYMPTOM DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
INSUFFICIENT COOLING
INSUFFICIENT COOLING
DescriptionINFOID:0000000009463167
Symptom
• Insufficient cooling
• No cool air comes out. (Air flow volume is normal.)
Diagnosis ProcedureINFOID:0000000009463168
NOTE:
Perform self-diagnoses with CONSULT before performi ng symptom diagnosis. If any DTC is detected, per-
form the corresponding diagnosis.
1.CHECK MAGNET CLUTCH OPERATION
1. Turn ignition switch ON.
2. Operate fan switch.
3. Press A/C switch.
4. Check that A/C indicator turns ON. Check visually and by sound that compressor operates.
5. Press A/C switch again.
6. Check that A/C indicator turns OFF. Check that compressor stops.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Perform diagnosis of “COMPRESSOR DOES NOT OPERATE” in “SYMPTOM DIAGNOSIS”.
Refer to HAC-99, "Diagnosis Procedure"
.
2.CHECK DRIVE BELT
Check tension of drive belt. Refer to EM-19, "Checking Drive Belts"
(QR25DE) or EM-134, "Checking Drive
Belts" (VQ35DE).
Is the inspection result normal?
YES >> GO TO 3.
NO >> Adjust or replace drive belt depending on the inspection results.
3.CHECK REFRIGERANT CYCLE
Connect recovery/recycling recharging equipment to the vehicle and perform pressure inspection with gauge.
Refer to HA-18, "Symptom Table"
.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace parts depending on the inspection results.
4.CHECK AIR LEAKAGE FROM EACH DUCT
Check duct and nozzle, etc. of the fr ont air conditioning system for leakage.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace parts depending on the inspection results.
5.CHECK AMBIENT TEMPERATURE DISPLAY
Check that there is not much difference between act ual ambient temperature and indicated temperature on
information display in combination meter.
Is the inspection result normal?
YES >> GO TO 6.
NO >> Perform diagnosis for the A/C auto amp. connection recognition signal circuit. Refer to HAC-60,
"Diagnosis Procedure".
6.CHECK SETTING OF TEMPERATURE SETTING TRIMMER (FRONT)
1. Check setting value of temperature setting trimmer (front). Refer to HAC-50, "Temperature Setting Trim-
mer".
2. Check that temperature setting trimme r (front) is set to “+ direction”.
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COMPRESSOR DOES NOT OPERATEHAC-99
< SYMPTOM DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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COMPRESSOR DOES NOT OPERATE
DescriptionINFOID:0000000009463171
Symptom: Compressor does not operate.
Diagnosis ProcedureINFOID:0000000009463172
NOTE:
• Perform self-diagnoses with CONSULT before perform ing symptom diagnosis. If DTC is detected, perform
the corresponding diagnosis.
• Check that refrigerant system is properly charged. If refrigerant amount is below the proper amount, perform
inspection of refrigerant leakage.
1.CHECK MAGNET CLUTCH OPERATION
Check magnet clutch. Refer to HAC-87, "Component Function Check"
.
Does it operate normally?
YES >> GO TO 2.
NO >> Repair or replace malfunctioning parts.
2.CHECK REFRIGERANT PRESSURE SENSOR
Check refrigerant pressure sensor. Refer to EC-523, "Component Function Check"
(QR25DE) or EC-979,
"Component Function Check" (VQ35DE).
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace malfunctioning parts.
3.CHECK A/C AUTO AMP. OUTPUT SIGNAL
With CONSULT
Check “COMP REQ SIG” and “FAN REQ SIG” in “D ATA MONITOR” mode of “HVAC” using CONSULT.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Replace A/C auto amp. Refer to HAC-102, "Removal and Installation"
.
4.CHECK ECM INPUT SIGNAL
With CONSULT
Check “AIR COND SIG” and “HEATER FAN SW” in “DATA MONITOR” mode of “ECM” using CONSULT.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Check CAN communication system. Refer to LAN-18, "Trouble Diagnosis Flow Chart"
.
5.CHECK IPDM E/R INPUT SIGNAL
With CONSULT
Monitor item Condition Status
COMP REQ SIG A/C switch ON On
OFF Off
FAN REQ SIG Blower motor ON On
OFF Off
Monitor item Condition Status
AIR COND SIG A/C switch ON On
OFF Off
HEATER FAN SW Blower motor ON On
OFF Off
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REFRIGERANT PRESSURE SENSORHAC-107
< REMOVAL AND INSTALLATION > [AUTOMATIC AIR CONDITIONER]
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REFRIGERANT PRESSURE SENSOR
Removal and InstallationINFOID:0000000009463180
REMOVAL
1. Discharge the refrigerant. Refer to HA-23, "Recycle Refrigerant".
2. Remove the front bumper fascia. Refer to EXT-17, "Removal and Installation"
.
3. Disconnect the harness connector from the refrigerant pressure sensor.
4. Remove the refrigerant pressure sensor. CAUTION:
Cap or wrap the opening of the refrigerant pressu re sensor with suitable material such as vinyl
tape to avoid the entry of air.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
• Do not reuse O-ring.
• Apply A/C oil to the O-ri ng of the refrigerant pressu re sensor for installation.
• After charging refrigerant, check for leaks. Refer to HA-21, "Leak Test"
.
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