2007 INFINITI QX56 cooling

TROUBLE DIAGNOSISATC-113
< SERVICE INFORMATION >
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Does another symptom exist?
YES >> Refer to ATC-32, "How to Perform Trouble Diagnosis for Quick and Accurate Repair".
NO >> Replace front air control. Refer to ATC-123, "
Removal and Installation".
Water Valve CircuitINFOID:0000000003533265
COMPONENT DESCRIPTION
Water Valve
The water valve (1) cuts the flow of engine coolant to the front and
rear heater cores to allow for maximum cooling during A/C opera-
tion. It is controlled by the front air control.
DIAGNOSTIC PROCEDURE FOR WATER VALVE
1.CHECK WATER VALVE POWER AND GROUND CIRCUITS
1. Disconnect water valve connector F68.
2. Turn ignition switch ON.
3. Rotate temperature control dial (driver) to 32 °C (90 °F).
4. Check voltage between water valve harness connector F68 ter- minal 1 and terminal 2 while rotating temperature control dial
(driver) to 16 °C (60 °F).
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2.CHECK WATER VALVE CONTROL OUTPUT CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front air control connector M50.
3. Check continuity between water valve harness connector F68 (A) terminal 1 and front air control harness connector M50 (B)
terminal 29.
4. Check continuity between water valve harness connector F68 (A) terminal 1 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-123, "Removal and Installation".
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ConnectorTe r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
Water valve: F68 1 2 Rotate temperature
control dial Battery
voltage
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1 - 29 : Continuity should exist.
1 - Ground : Continuity should not exist.
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TROUBLE DIAGNOSISATC-121
< SERVICE INFORMATION >
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The intake sensor is located on the heater & cooling unit. It converts
temperature of air after it passes through the evaporator into a resis-
tance value which is then input to the front air control.
DIAGNOSTIC PROCEDURE FOR INTAKE SENSOR
SYMPTOM: Intake sensor circuit is open or shorted. Using the CON-
SULT-II, DTC B2581 or B2582 is di splayed. Without a CONSULT-II,
code 56 or 57 is indicated on front air control as a result of conduct-
ing the front air control self-diagnosis.
1.CHECK VOLTAGE BETWEEN INTAKE SENSOR AND GROUND
1. Disconnect intake sensor connector.
2. Turn ignition switch ON.
3. Check voltage between intake sensor harness connector M146 terminal 2 and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
2.CHECK CIRCUIT CONTINUITY BETWEEN IN TAKE SENSOR AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector.
3. Check continuity between intake sensor harness connector M146 terminal 1 and front air control harness connector M49 ter-
minal 21.
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
3.CHECK INTAKE SENSOR
Refer to "Intake Sensor Circuit".
OK or NG
OK >> 1. Replace front air control. Refer to ATC-123, "Removal and Installation"
2. Go to ATC-48, "A/C System Self-Diagnosis Function" and perform self-diagnosis.
NG >> 1. Replace intake sensor. Refer to ATC-127
.
2. Go to ATC-48, "
A/C System Self-Diagnosis Function" and perform self-diagnosis.
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WJIA0464E
2 - Ground : Approx. 5V
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1 - 21 : Continuity should exist.
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INTAKE SENSORATC-127
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INTAKE SENSOR
Removal and InstallationINFOID:0000000003533274
REMOVAL
1. Remove the glove box . Refer to IP-10, "Removal and Installation".
2. Disconnect the intake sensor electrical connector. NOTE:
The intake sensor is located on the top of the front heater and
cooling unit assembly next to the A/C evaporator cover.
3. Twist the intake sensor to remove the intake sensor from the front heater and cooling unit assembly.
INSTALLATION
Installation is in the reverse order of removal.
LJIA0133E

ATC-128
< SERVICE INFORMATION >
BLOWER MOTOR
BLOWER MOTOR
ComponentINFOID:0000000003533275
Front Blower MotorRear Blower Motor
Removal and InstallationINFOID:0000000003533276
FRONT BLOWER MOTOR
Removal
1. Remove the glove box assembly. Refer to IP-10, "Removal and Installation".
2. Disconnect the front blower motor electrical connector.
3. Remove the three screws and remove the front blower motor.
Installation
Installation is in the reverse order of removal.
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1. Front heater and cooling unit assembly 2. Front blower motor 3. Variable blower control
LJIA0055E
1. Rear blower motor 2. Rear blower motor case 3. Rear blower motor resistor

ATC-130
< SERVICE INFORMATION >
IN-CABIN MICROFILTER
IN-CABIN MICROFILTER
Removal and InstallationINFOID:0000000003533277
FUNCTION
The air inside the passenger compartment is filtered by the in-cabin
microfilters when the heater or A/C controls are set on either the
recirculation or fresh mode. The two in-cabin microfilters are located
in the front heater and cooling unit assembly. The rear heater and
cooling unit assembly only draws in air from the passenger compart-
ment to recirculate into the passenger compartment, so the rear
heater and cooling unit assembly is not equipped with in-cabin
microfilters.
REPLACEMENT TIMING
Replacement of the two in-cabin microfilters is recommended on a regular interval depending on the driving
conditions. Refer to MA-6
. It may also be necessary to replace the tw o in-cabin microfilters as part of a compo-
nent replacement if the in-cabin microfilters are damaged.
REPLACEMENT PROCEDURE
1. Remove the two lower glove box hinge pins to remove the glove box from the instrument panel and let it hang from the cord.
2. Remove the screw and remove the in-cabin microfilter cover.
3. Remove the in-cabin microfilters from the front heater and cool- ing unit assembly housing.
4. Insert the first new in-cabin micr ofilter into the front heater and
cooling unit assembly housing and slide it over to the right.
Insert the second new in-cabin mi crofilter into the front heater
and cooling unit assembly housing.
NOTE:
The in-cabin microfilters are marked with air flow arrows. The
end of the microfilter with the arro w should face the rear of the
vehicle. The arrows should point downward.
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WLIA0027E
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ATC-132
< SERVICE INFORMATION >
HEATER & COOLING UNIT ASSEMBLY
HEATER & COOLING UNIT ASSEMBLY
ComponentINFOID:0000000003533278
Front Heater and Cooling Unit Assembly
AWJIA0319ZZ
1. High-pressure A/C pipe 2. Front expansion valve 3. Low-pressure A/C pipe
4. Front heater core pipe 5. Front heater core hose 6. A/C drain hose
7. Front heater and cooling unit assembly

HEATER & COOLING UNIT ASSEMBLYATC-133
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Rear Heater and Cooling Unit Assembly
Removal and InstallationINFOID:0000000003533279
FRONT HEATER AND COOLING UNIT ASSEMBLY
Removal
1. Move the two front seats to the rearmost position on the seat track.
2. Disconnect the battery negative terminal and battery positive terminal.
3. Discharge the refrigerant from the A/C system. Refer to ATC-150, "
HFC-134a (R-134a) Service Proce-
dure".
4. Drain the coolant from the engine cooling system. Refer to MA-12, "
Changing Engine Coolant".
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1. Rear heater and cooling unit assembly 2. Rear A/C pipes 3. Rear A/C heater core pipes
4. Rear heater core hose 5. Rear blower motor 6. Underfloor rear A/C pipes
7. Underfloor rear heater core pipes A. Bolt torque specifications B. Leak checking order (l - r)
C. Tightening torque D. Wrench size E. O-ring size
⇐Front
NOTE: The O-ring size 8 is the high-side and the O-ring size 16 is the low-side.

ATC-134
< SERVICE INFORMATION >
HEATER & COOLING UNIT ASSEMBLY
5. Disconnect the front heater hoses from the front heater core.
6. Disconnect the high/low pressure pipes from the front expansion valve.
7. Remove the instrument panel and console panel. Refer to IP-10, "
Removal and Installation".
8. Remove the steering column. Refer to PS-10
.
9. Disconnect the instrument panel wire harness at the RH and LH in-line connector brackets, and the fuse
block (J/B) electrical connectors. Refer to PG-3
.
10. Disconnect the steering member from each side of the vehicle body.
11. Remove the front heater and cooling unit assembly with it attached to the steering member, from the vehi-
cle.
CAUTION:
Use care not to damage the seats and interior tr im panels when removing the front heater and
cooling unit assembly with it at tached to the steering member.
12. Remove the front heater and cooling unit assembly from the steering member.
Installation
Installation is in the reverse order of removal.
CAUTION:
• Replace the O-ring of the low-pressure pipe and high-pressure pipe with a new one, and apply com-
pressor oil to it when installing it.
• After charging the refrigerant, check for leaks.
NOTE:
• Fill the engine cooling system with the s pecified coolant mixture. Refer to MA-12, "
Changing Engine Cool-
ant".
• Recharge the A/C system. Refer to ATC-150, "
HFC-134a (R-134a) Service Procedure".
REAR HEATER AND COOLING UNIT ASSEMBLY
Removal
1. Discharge the refrigerant from the A/C system. Refer to ATC-150, "HFC-134a (R-134a) Service Proce-
dure".
2. Drain the coolant from the engine cooling system. Refer to MA-12, "
Changing Engine Coolant".
3. Disconnect the rear heater core hoses from the rear heater core.
4. Disconnect the rear A/C pipes from the rear expansion valve.
5. Remove the luggage side finisher lower RH. Refer to EI-34
.
6. Disconnect the following electrical connectors: • Rear blower motor
• Rear blower motor resistor
• Rear air mix door motor
7. Disconnect the ducts from the rear heater and cooling unit assembly.
8. Remove the rear heater and cooling unit assembly.
Installation
Installation is in the reverse order of removal.
CAUTION:
• Replace the O-ring of the low-pressure pipe and high-pressure pipe with a new one, and apply com-
pressor oil to it when installing it.
• After charging the refrigerant, check for leaks.
NOTE:
• Fill the engine cooling system with the s pecified coolant mixture. Refer to MA-12, "
Changing Engine Cool-
ant".
• Recharge the A/C system. Refer to ATC-150, "
HFC-134a (R-134a) Service Procedure".
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