2007 INFINITI QX56 check engine

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".
WJIA2315E
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".
LJIA0021E

ATC-154
< SERVICE INFORMATION >
REFRIGERANT LINES
Removal and Installation for Compressor
INFOID:0000000003533293
A/C Compressor Mounting
REMOVAL
1. Discharge the refrigerant. Refer to ATC-150, "HFC-134a (R-134a) Service Procedure".
2. Remove the front right wheel and tire assembly. Refer to WT-7, "
Rotation".
3. Remove the engine under cover and the splash shield using power tool.
4. Remove the engine air cleaner and air ducts. Refer to EM-15
.
5. Remove the drive belt. Refer to EM-13
.
6. Disconnect the compressor electrical connector.
7. Disconnect the high-pressure flexible hose and low- pressure flexible hose from the compressor.
CAUTION:
Cap or wrap the joint of the pipe with suitable mate rial such as vinyl tape to avoid the entry of air.
8. Remove the compressor bolts and nut using power tools.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
• Replace the O-rings of the low-pressure flexibl e hose and high-pressure flexible hose with new
ones, apply compressor oil to the O-rings when installing them.
• After recharging the A/C system with refrigerant, check for leaks.
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REFRIGERANT LINESATC-157
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3. Install the pulley assembly using Tool and a wrench, then install the snap ring using snap ring pliers.
4. Install the clutch disc on the co mpressor shaft, together with the
original shim(s). Press the clutch disc down by hand.
5. Install the clutch pulley bolt using Tool, to prevent the clutch disc from turning and tighten the bolt to specification.
CAUTION:
After tightening the clutch pul ley bolt, check that the clutch
pulley rotates smoothly.
6. Check the pulley clearance all the way around the clutch disc as shown.
7. If the specified clearance is not obtained, replace the adjusting spacer to readjust.
8. Connect the compressor electrical connector.
9. Install the drive belt. Refer to EM-13
.
10. Install the engine under cover and the splash shield. Tool number : — (J-38873-A)
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WHA184
Tool number : J-44614
WHA229
Clutch disc-to-pulley clearance : 0.3 - 0.6 mm
(0.012 - 0.024 in)
WHA194

ATC-158
< SERVICE INFORMATION >
REFRIGERANT LINES
BREAK-IN OPERATION
When replacing compressor clutch assembly, always conduct the break-in operation. This is done by engag-
ing and disengaging the clutch about 30 times. Break-in operation raises the level of transmitted torque.
Removal and Installation for Low-Pressure Flexible HoseINFOID:0000000003533295
REMOVAL
1. Remove the engine room cover using power tools.
2. Remove the engine air cleaner and air ducts. Refer to EM-15
.
3. Remove the cowl top extension. Refer to EI-17
.
4. Discharge the refrigerant. Refer to ATC-150, "
HFC-134a (R-134a) Service Procedure".
CAUTION:
Cap or wrap the joint of the pipe with suitable mate rial such as vinyl tape to avoid the entry of air.
5. Remove the low-pressure flexible hose.
INSTALLATION
Installation is in the reverse order of removal.
Refer to ATC-152, "
Component".
CAUTION:
• Replace the O-ring of the low-pr essure flexible hose with a new one, then apply compressor oil to it
when installing it.
• After charging refrigerant, check for leaks.
Removal and Installation for High-pressure Flexible HoseINFOID:0000000003533296
REMOVAL
1. Remove the engine under cover.
2. Remove the engine air cleaner and air ducts. Refer to EM-15
.
3. Discharge the refrigerant. Refer to ATC-150, "
HFC-134a (R-134a) Service Procedure".
4. Remove the high-pressure flexible hose. CAUTION:
Cap or wrap the joint of the pipe with suitable mate rial such as vinyl tape to avoid the entry of air.
INSTALLATION
Installation is in the reverse order of removal.
Refer to ATC-152, "
Component".
CAUTION:
• Replace the O-ring of the high-pressure flexible hose with a new one, then apply compressor oil to it
when installing it.
• After charging refrigerant, check for leaks.
Removal and Installation for High-pressure PipeINFOID:0000000003533297
REMOVAL
1. Remove the cowl top extension. Refer to EI-17.
2. Disconnect the battery negative terminal and positive battery terminal.
3. Reposition the IPDM E/R aside.
4. Remove the front right wheel and tire assembly. Refer to WT-7, "
Rotation".
5. Position aside the front floor insulator.
6. Discharge the refrigerant. Refer to ATC-150, "
HFC-134a (R-134a) Service Procedure".
7. Remove the low-pressure pipe. Refer to ATC-159, "
Removal and Installation for Low-Pressure Pipe".
8. Remove the high-pressure pipe. CAUTION:
Cap or wrap the joint of the pipe with suitable mate rial such as vinyl tape to avoid the entry of air.
INSTALLATION
Installation is in the reverse order of removal.

REFRIGERANT LINESATC-159
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Refer to ATC-152, "Component".
CAUTION:
• Replace the O-ring of the high-pressure pipe with a new one, then apply compressor oil to it when
installing it.
• After charging refrigerant, check for leaks.
Removal and Installation for Low-Pressure PipeINFOID:0000000003533298
REMOVAL
1. Discharge the refrigerant. Refer to ATC-150, "HFC-134a (R-134a) Service Procedure".
2. Remove the cowl top and the cowl top extension. Refer to EI-17
.
3. Remove the low-pressure pipe. CAUTION:
Cap or wrap the joint of the pipes with suitable material such as viny l tape to avoid the entry of air.
INSTALLATION
Installation is in the reverse order of removal.
Refer to ATC-152, "
Component".
CAUTION:
• Replace the O-ring of the high/low-pressure pipe with a new one, then apply compressor oil to it
when installing it.
• After charging refrigerant, check for leaks.
Removal and Installation for Rear High- and Low-Pressure A/C and Heater Core Pipes
INFOID:0000000003533299
REMOVAL
1. Discharge the refrigerant. Refer to ATC-150, "HFC-134a (R-134a) Service Procedure".
2. Drain the coolant from the engine cooling system. Refer to CO-9, "
Changing Engine Coolant".
3. Disconnect the underfloor rear heater hoses (1 and 2) from the rear heater pipes underneath the vehicle.
•⇐ : Front
4. Remove the rear high- and low-pressure pipes bolt (A) to dis- connect the rear high- and low-pressure pipes from the under-
floor rear high- and low-pressu re pipes underneath the vehicle.
CAUTION:
Cap or wrap the joint of the pipes with suitable material
such as vinyl tape to avo id the entry of air.
5. Remove the rear high- and low-pressure pipes nuts (B) under- neath the vehicle.
NOTE:
The remaining steps are performed inside the rear luggage area of the vehicle.
6. Remove the luggage side finisher lower RH. Refer to EI-39
.
7. Disconnect the rear heater core hoses (1 and 2) from the rear heater core (3).
•⇐ : Front
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WJIA2311E

ATC-160
< SERVICE INFORMATION >
REFRIGERANT LINES
8. Remove the rear high- and low-pressure pipes bracket bolt (A)to release the bracket.
• Rear blower motor (1)
•⇐ : Front
9. Remove the rear high- and low-pressure pipes bolt (A) to dis- connect the rear high- and low-pressure pipes from the rear
expansion valve (1).
•⇐ : Front
CAUTION:
Cap or wrap the joint of the pipes with suitable material
such as vinyl tape to avoid the entry of air.
10. Disconnect the following electrical connectors: • Rear air mix door motor (1)
• Rear blower motor resistor (2)
• Rear blower motor (3)
•⇐ : Front
11. Disconnect the ducts from the rear heater and cooling unit assembly. Refer to ATC-145, "
Component".
12. Remove the rear heater and cooling unit assembly. CAUTION:
Cap or wrap the joint of the pipes with suitable material such as viny l tape to avoid the entry of air.
13. Remove the rear high- and low-pressure A/C pipes.
INSTALLATION
Installation is in the reverse order of removal.
Refer to ATC-152, "
Component".
CAUTION:
• Replace the O-ring of th e high/low-pressure pipe with a new one, then apply compressor oil to it
when installing it.
• After charging refrigerant, check for leaks.
Removal and Installati on for Underfloor Rear High- and Low-Pressure A/C and Heater
Core Pipes
INFOID:0000000003533300
REMOVAL
1. Drain the coolant from the engine cooling system. Refer to CO-9, "Changing Engine Coolant".
2. Disconnect the battery negative terminal.
3. Disconnect the generator harness.
4. Discharge the refrigerant. Refer to ATC-150, "
HFC-134a (R-134a) Service Procedure".
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REFRIGERANT LINESATC-167
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If repairing the A/C system or replacing a com ponent, pour the HFC-134a (R-134a) fluorescent leak
detection dye (J-41447) directly into the open system connection and proceed with the service
procedures.
3. Connect the refrigerant dye injector (J- 41459) to the low-pressure service valve.
4. Start the engine and switch the A/C system ON.
5. When the A/C system is operating (compressor runni ng), inject one bottle 7.4 cc (1/4 ounce) of HFC-134a
(R-134a) fluorescent leak detection dye (J-41447) th rough the low-pressure service valve using HFC-
134a (R-134a) dye injector (J-41459). Refer to the manufacturer's operating instructions.
6. With the engine still running, disconnect the HFC-134a (R -134a) dye injector (J-41459) from the low-pres-
sure service valve.
7. Operate the A/C system for a minimum of 20 minut es to mix the HFC-134a (R-134a) fluorescent leak
detection dye (J-41447) with the A/C system oil. Depending on the leak size, operating conditions and
location of the leak, it may take from minutes to days for the HFC-134a (R-134a) fluorescent leak detec-
tion dye to penetrate an A/C system leak and become visible.
Electronic Refrigerant Leak DetectorINFOID:0000000003533310
PRECAUTIONS FOR HANDLING LEAK DETECTOR
NOTE:
When performing a refrigerant leak check, use a electr onic refrigerant leak detector (J-41995) or equivalent.
Ensure that the electronic refrigerant leak detector (J-41995) is calibrated and set properly according to the
manufacturer's operating instructions.
The electronic refrigerant leak detector (J-41995) is a delicate
device. To use the electronic refrigerant leak detector (J-41995)
properly, read the manufacturer's operating instructions and perform
any specified maintenance.
1. Position the probe approximately 5 mm (3/16 in) away from the point to be checked as shown.
2. When checking for leaks, circle each fitting completely with the probe as shown.
AHA281A
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