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-78
< DTC/CIRCUIT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
POWER SUPPLY AND GROUND CIRCUIT
POWER SUPPLY AND GROUND CIRCUIT
A/C AUTO AMP.
A/C AUTO AMP. : Diagnosis ProcedureINFOID:0000000009463149
Regarding Wiring Diagram information, refer to
HAC-34, "Wiring Diagram".
1.CHECK FUSE
Check fuses [No. 14, 25 and 30, loca ted in the fuse block (J/B)].
NOTE:
Refer to PG-70, "Terminal Arrangement"
.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Replace the blown fuse after repairing the affected circuit.
2.CHECK A/C AUTO AMP. POWER SUPPLY
1. Turn ignition switch OFF.
2. Disconnect A/C auto amp. connector.
3. Check voltage between A/C auto amp. harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair harness or connector between A/C auto amp. and fuse block (J/B).
3.CHECK A/C AUTO AMP. GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check continuity between A/C auto amp. harness connector and ground.
Is the inspection result normal?
YES >> Inspection End.
NO >> Repair harness or connector.
AIR MIX DOOR MOTOR (DRIVER SIDE)
AIR MIX DOOR MOTOR (DRIVE R SIDE) : Diagnosis ProcedureINFOID:0000000009463150
Regarding Wiring Diagram information, refer to HAC-34, "Wiring Diagram".
+
− Vo l ta g e
A/C auto amp. Ignition switch position
Connector Terminal OFF ACC ON
M152 3
GroundBattery voltage Battery voltage Battery voltage
13 Approx. 0 V Battery voltage Battery voltage
23 Approx. 0 V Approx. 0 V Battery voltage
40 Approx. 0 V Approx. 0 V Battery voltage
A/C auto amp. —Continuity
Connector Terminal
M152 2
Ground Yes
22
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HAC-84
< DTC/CIRCUIT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
BLOWER MOTOR
BLOWER MOTOR
Diagnosis ProcedureINFOID:0000000009463156
Regarding Wiring Diagram information, refer to
HAC-34, "Wiring Diagram".
1.CHECK FUSE
1. Turn ignition switch OFF.
2. Check 15A fuses [Nos. 17 and 27, located in fuse block (J/B)].
NOTE:
Refer to PG-70, "Terminal Arrangement"
.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Replace the blown fuse after repairing the affected circuit.
2.CHECK BLOWER MOTOR POWER SUPPLY
1. Disconnect blower motor connector.
2. Turn ignition switch ON.
3. Check voltage between blower motor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 6.
3.CHECK BLOWER MOTOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check continuity between blower motor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair harness or connector.
4.CHECK BLOWER MOTOR CONTROL SIGNAL CIRCUIT
1. Disconnect A/C auto amp. connector.
2. Check continuity between blower motor harne ss connector and A/C auto amp. harness connector.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair the harness or connector.
5.CHECK BLOWER MOTOR CONTROL SIGNAL
+
−Voltage
(Approx.)
Blower motor
Connector Terminal M31 38 Ground Battery voltage
Blower motor —Continuity
Connector Terminal
M31 39 Ground Yes
Blower motor A/C auto amp. Continuity
Connector Terminal Connector Terminal
M31 17 M152 18 Yes
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
COMPONENT PARTSHAC-115
< SYSTEM DESCRIPTION > [MANUAL AIR CONDITIONER]
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Component DescriptionINFOID:0000000009463193
7. Refrigerant pressure sensor (view with front bumper fascia removed) 8. Blower motor (view with front air con-
ditioning assembly removed from ve-
hicle) 9. Intake door motor
10. Mode door motor 11. Air mix door motor
Component Description
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.
Air mix door motor The air mix door controls the mix of hot or cold air that enters the ventilation system. It is controlled
by the front air control based on the position of the temperature dial. The air mix door motor receives
position commands from the front air control 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 In-
terconnect 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 returns that information to the front
air control. The LCU switches the polarity of the circuits connected to the DC motor to drive the motor
forward or backward as requested by the front air control.
BCM The BCM receives the fan ON and A/C ON signals from the front air control 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 front air control via
CAN communication line.
Front air control The front air control 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, and inputs received from the
ECM and combination meter across the CAN.
Front blower motor relay The front blower motor relay controls the flow of current to fuses 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 front
air control may command partial fresh or recirculation based on evaporator or coolant temperatures.
The intake door motor receives position commands from the front air control 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 front air control. The LCU switches the polarity of the circuits connected
to the DC motor to drive the motor forward or backward as requested by the front air control.
IPDM E/R Refer to PCS-6, "RELAY CONTROL SYSTEM : System Description"
.
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
HAC-148
< DTC/CIRCUIT DIAGNOSIS >[MANUAL AIR CONDITIONER]
BLOWER MOTOR
BLOWER MOTOR
Diagnosis ProcedureINFOID:0000000009463214
Regarding Wiring Diagram information, refer to
HAC-130, "Wiring Diagram".
1.CHECK FUSE
1. Turn ignition switch OFF.
2. Check 15A fuses [Nos. 17 and 27, located in fuse block (J/B)].
NOTE:
Refer to PG-70, "Terminal Arrangement"
.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Replace the blown fuse after repairing the affected circuit.
2.CHECK BLOWER MOTOR POWER SUPPLY
1. Disconnect blower motor connector.
2. Turn ignition switch ON.
3. Check voltage between blower motor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 6.
3.CHECK BLOWER MOTOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check continuity between blower motor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair harness or connector.
4.CHECK BLOWER MOTOR CONTROL SIGNAL CIRCUIT
1. Disconnect front air control connector.
2. Check continuity between blower motor harness connector and front air control harness connector.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair the harness or connector.
5.CHECK BLOWER MOTOR CONTROL SIGNAL
+
−Voltage
(Approx.)
Blower motor
Connector Terminal M31 38 Ground Battery voltage
Blower motor —Continuity
Connector Terminal
M31 39 Ground Yes
Blower motor Front air control Continuity
Connector Terminal Connector Terminal
M31 17 M37 11 Yes
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
HAC-152
< DTC/CIRCUIT DIAGNOSIS >[MANUAL AIR CONDITIONER]
POWER SUPPLY AND GROUND CIRCUIT FOR FRONT AIR CONTROL
POWER SUPPLY AND GROUND CIRC
UIT FOR FRONT AIR CONTROL
DescriptionINFOID:0000000009463219
COMPONENT DESCRIPTION
Front air control.
The front air control has a built-in microcomputer that processes inform ation sent from various sensors
needed for air conditioner operation. The air mix door motor, the mode door motor, the intake door motor, the
blower motor and the A/C compressor are then controlled.
Component Function CheckINFOID:0000000009463220
1.CHECK OPERATION
1. Turn the blower motor dial clockwise and verify t he blower speed increases and that one of the LEDs illu-
minates on the mode switch.
2. Press the mode switches and verify that the modes change, the LEDs illuminate, and that air flows from
the various vents.
3. Turn the temperature control dial and verify the temperature changes at the selected vents.
4. Press the DEF and REC buttons and verify air flow changes.
Does it operate normally?
YES >> Inspection End.
NO >> Perform trouble diagnosis for the front air control system. Refer to HAC-152, "Diagnosis Proce-
dure".
Diagnosis ProcedureINFOID:0000000009463221
Regarding Wiring Diagram information, refer to HAC-130, "Wiring Diagram".
1.CHECK FRONT AIR CONTROL POWER SUPPLY
1. Turn ignition switch OFF.
2. Disconnect the front air control connector.
3. Turn ignition switch ON.
4. Check voltage between front air control har ness connector M37 terminals 1, 2 and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK FUSE
Check fuses [Nos. 14 and 30, located in the fuse block (J/B)].
NOTE:
Refer to PG-70, "Terminal Arrangement"
.
Is the inspection result normal?
YES >> Check harness for open circuit. Repair or replace if necessary.
NO >> Check harness for short circuit. Repair or replace if necessary.
3.CHECK FRONT AIR CONTROL GROUND CIRCUIT
(+) (−)Voltage
Front air control —Ignition switch position
Connector Terminal OFF ACC ON
M37 1
Ground Battery
voltage Battery
voltage Battery
voltage
2 Approx. 0V Approx. 0V Battery
voltage
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MWI-58
< DTC/CIRCUIT DIAGNOSIS >
POWER SUPPLY AND GROUND CIRCUIT
POWER SUPPLY AND GROUND CIRCUIT
COMBINATION METER
COMBINATION METER : Diagnosis ProcedureINFOID:0000000009461715
Regarding Wiring Diagram information, refer to MWI-32, "Wiring Diagram".
1.CHECK FUSES
Check that the following fuses are not blown.
Is the fuse blown?
YES >> Replace the blown fuse after repairing the affected circuit.
NO >> GO TO 2.
2.POWER SUPPLY CIRCUIT CHECK
1. Disconnect combination meter connector.
2. Check voltage between combination meter har ness connector M24 terminals 5, 21, 22 and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace harness or connectors.
3.GROUND CIRCUIT CHECK
1. Turn ignition switch OFF.
2. Check continuity between combination mete r harness connector M24 terminals 1, 2 and ground.
Is the inspection result normal?
YES >> Inspection End.
NO >> Repair or replace harness or connectors.
BCM (BODY CONTROL MODULE)
BCM (BODY CONTROL MODULE) : Diagnosis ProcedureINFOID:0000000009940932
Regarding Wiring Diagram information, refer to BCS-55, "Wiring Diagram".
Unit Power source Fuse No.
Combination meter Battery 13
25
Ignition switch ON or START 31
Terminals Ignition switch position
(+) (–) OFF ACC ON START
Connector Terminal
M24 22
GroundBattery voltage Battery voltage Battery voltage Battery voltage
21 0V 0V Battery voltage Battery voltage 5 0V Battery voltage Battery voltage 0V
Te r m i n a l s Continuity
(+)
(–)
Connector Terminal
M24 1
Ground Yes
2
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DIAGNOSIS SYSTEM (AIR BAG)SRC-15
< SYSTEM DESCRIPTION >
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DIAGNOSIS SYSTEM (AIR BAG)
Diagnosis DescriptionINFOID:0000000009460723
CAUTION:
• Do not use electrical test equipment on any circui t related to the SRS unless instructed to do so in
this Service Manual. SRS wiring harnesses can be id entified by yellow and/or orange harness con-
nectors.
• Do not attempt to repair, splice or modify SRS wiring harnesses. If a harness is damaged, replace it
with a new one.
• Keep ground connections clean.
HOW TO PERFORM TROUBLE DIAGNOSES FOR QUICK AND ACCURATE REPAIR
1. Obtain information about the symptom.
- WHAT - vehicle model
- WHEN - date, frequencies
- WHERE - road conditions
- HOW - operating conditions, symptoms, passengers
2. Perform Preliminary Check.
-Battery
- Fuses
- Harness connections
DIAGNOSIS METHODS
SRS self-diagnosis results can be read by using the AIR BAG warning lamp or CONSULT.
The User Mode is for the customer (driver). This m ode warns the driver of a system malfunction through the
AIR BAG warning lamp.
The Diagnosis Mode is for the technician. This mode hel ps the technician locate the malfunctioning circuit or
part.
SRS Operation CheckINFOID:0000000009460724
USER MODE
1. Turn the ignition switch from OFF to ON and check that the air bag warning lamp flashes.
2. Compare the flashing pattern with the examples in the table.
User Mode Diagnosis Mode Display type
AIR BAG warning lamp X X ON/OFF CONSULT — X Monitoring
BF-1845D
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM