variable INFINITI QX56 2006 Factory Service Manual

ATC-3
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Revision: November 2009 2006 QX56
DIAGNOSTIC PROCEDURE FOR IN-VEHICLE
SENSOR ..........................................................
. 138
COMPONENT INSPECTION ........................... . 140
Optical Sensor Circuit ......................................... . 140
COMPONENT DESCRIPTION ........................ . 140
OPTICAL INPUT PROCESS ........................... . 140
DIAGNOSTIC PROCEDURE FOR OPTICAL
SENSOR .......................................................... . 141
Intake Sensor Circuit ........................................... . 142
COMPONENT DESCRIPTION ........................ . 142
DIAGNOSTIC PROCEDURE FOR INTAKE SEN-
SOR ................................................................. . 142
COMPONENT INSPECTION ........................... . 143
CONTROL UNIT .................................................... . 144
Removal and Installation ..................................... . 144
FRONT AIR CONTROL ................................... . 144
REAR AIR CONTROL ...................................... . 144
AMBIENT SENSOR ............................................... . 145
Removal and Installation ..................................... . 145
REMOVAL ........................................................ . 145
INSTALLATION ................................................ . 145
IN-VEHICLE SENSOR ........................................... . 146
Removal and Installation ..................................... . 146
REMOVAL ........................................................ . 146
INSTALLATION ................................................ . 146
OPTICAL SENSOR ............................................... . 147
Removal and Installation ..................................... . 147
INTAKE SENSOR .................................................. . 148
Removal and Installation ..................................... . 148
REMOVAL ........................................................ . 148
INSTALLATION ................................................ . 148
BLOWER MOTOR ................................................. . 149
Components ........................................................ . 149
Removal and Installation ..................................... . 149
FRONT BLOWER MOTOR .............................. . 149
REAR BLOWER MOTOR ................................ . 150
IN-CABIN MICROFILTER ...................................... . 151
Removal and Installation ..................................... . 151
FUNCTION ....................................................... . 151
REPLACEMENT TIMING ................................. . 151
REPLACEMENT PROCEDURE ...................... . 151
HEATER & COOLING UNIT ASSEMBLY ............. . 153
Components ........................................................ . 153
Removal and Installation ..................................... . 154
FRONT HEATER AND COOLING UNIT ASSEM-
BLY ................................................................... . 154
REAR HEATER AND COOLING UNIT ASSEM-
BLY ................................................................... . 155
HEATER CORE ..................................................... . 156
Components ........................................................ . 156
Removal and Installation ..................................... . 157
FRONT HEATER CORE .................................. . 157
REAR HEATER CORE .................................... . 158
DEFROSTER DOOR MOTOR ............................... . 159
Removal and Installation ..................................... . 159
REMOVAL ........................................................ . 159
INSTALLATION ................................................ . 159INTAKE DOOR MOTOR ........................................
.160
Removal and Installation ..................................... .160
REMOVAL ........................................................ .160
INSTALLATION ................................................ .160
MODE DOOR MOTOR ........................................... .161
Removal and Installation ..................................... .161
REMOVAL ........................................................ .161
INSTALLATION ................................................ .161
AIR MIX DOOR MOTOR ........................................ .162
Components ........................................................ .162
Removal and Installation ..................................... .162
FRONT AIR MIX DOOR MOTOR (DRIVER) .... .162
FRONT AIR MIX DOOR MOTOR (PASSENGER) .163
REAR AIR MIX DOOR MOTOR ....................... .163
VARIABLE BLOWER CONTROL .......................... .164
Removal and Installation ..................................... .164
REMOVAL ........................................................ .164
INSTALLATION ................................................ .164
REAR BLOWER MOTOR RESISTOR ................... .165
Removal and Installation ..................................... .165
REMOVAL ........................................................ .165
INSTALLATION ................................................ .165
DUCTS AND GRILLES .......................................... .166
Components ........................................................ .166
Removal and Installation ..................................... .169
CENTER CONSOLE HEAT DUCT AND REAR
FINISHER ASSEMBLY GRILLE ....................... .169
DEFROSTER NOZZLE .................................... .169
RH AND LH SIDE DEMISTER DUCT .............. .169
RH AND LH VENTILATOR DUCT .................... .169
CENTER VENTILATOR DUCT ........................ .169
FLOOR DUCT .................................................. .169
REAR OVERHEAD DUCTS ............................. .170
REAR FLOOR DUCT ....................................... .170
GRILLES .......................................................... .170
REFRIGERANT LINES .......................................... .171
HFC-134a (R-134a) Service Procedure .............. .171
SETTING OF SERVICE TOOLS AND EQUIP-
MENT ............................................................... .171
Components ........................................................ .173
Removal and Installation for Compressor ........... .175
REMOVAL ........................................................ .175
INSTALLATION ................................................ .176
Removal and Installation for Compressor Clutch . 176 REMOVAL ........................................................ .176
INSPECTION ................................................... .177
INSTALLATION ................................................ .177
BREAK-IN OPERATION ................................... .179
Removal and Installation for Low-pressure Flexible
Hose .................................................................... .179
REMOVAL ........................................................ .179
INSTALLATION ................................................ .179
Removal and Installation for High-pressure Flexible
Hose .................................................................... .179
REMOVAL ........................................................ .179
INSTALLATION ................................................ .179
Removal and Installation for High-pressure Pipe . 179 REMOVAL ........................................................ .179
INSTALLATION ................................................ .179

TROUBLE DIAGNOSISATC-41
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Revision: November 2009 2006 QX56
FRONT PASSENGER COMPARTMENT
1 Front air control M49, M502 Rear blower switch (front) M52 3 In-vehicle sensor M32
4 Intake sensor M146 5 Intake door motor M586 Variable blower control M122
7 Air mix door motor (passenger) M143 8 Mode door motor M142
9 Defroster door motor M144
10 Air mix door motor (driver) M147 11 Optical sensor M402
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ATC-54
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
Front Air Control Terminals and Reference ValueEJS003XJ
Measure voltage between each terminal and ground by following
Terminals and Reference Value for front air control.
PIN CONNECTOR TERMINAL LAYOUT
TERMINALS AND REFERENCE VALUE FOR FRONT AIR CONTROL
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Te r m i -
nal No. Wire
color ItemIgnition
switch Condition Voltage (V)
(Approx.)
1 B Ground -- 0V
2 Y Sensor power ON- 5V
3 W/G Air mix door motor (Driver) CW ON Clockwise rotation Battery voltage
4 G Air mix door motor (Driver) CCW ON Counterclockwise rotation Battery voltage
5 BR/W Mode door motor CW ON Clockwise rotationBattery voltage
6 P/L Mode door motor CCW ON Counterclockwise rotationBattery voltage
7 O Intake door motor CCW ON Counterclockwise rotationBattery voltage
8 G/B Intake door motor CW ON Clockwise rotationBattery voltage
9 L/B Intake sensor ON- 0 - 5V
10 L/R Fan ON signal ON Blower switch OFF
5V
ON Blower switch ON 0V
11 Y/B Rear defroster request ON- Battery voltage
12 W/R Compressor ON signal ON A/C switch OFF
5V
ON A/C switch ON 0V
13 G/R Variable blower control ON- 0 - 5V
14 Y/G Power supply for IGN ON- Battery voltage
15 P Sensor ground ON- 0V
16 GR Mode door motor feedback ON- 0 - 5V
17 P Ambient sensor ON- 0 - 5V
18 SB Air mix door motor (Driver) feedback ON -0 - 5V
19 LG Defroster door motor CW ON Clockwise rotationBattery voltage
20 P/B Defroster door motor CCW ON Counterclockwise rotationBattery voltage
21 V/R Sensor return ON- 0 - 5V

ATC-94
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
SYSTEM DESCRIPTION
Component Parts
Blower speed control system components are:

Front air control

Variable blower control

Front blower motor relay

Front blower motor

In-vehicle sensor

Ambient sensor

Optical sensor

Intake sensor
System Operation
Automatic Mode
In the automatic mode, the blower motor speed is calculated by the front air control and variable blower control
based on input from the in-vehicle sensor, optical sensor, intake sensor and ambient sensor, and potentio tem-
perature control (PTC).
When the air flow is increased, the blower motor speed is adjusted gradually to prevent a sudden increase in
air flow.
In addition to manual air flow control and the usual automatic air flow control, starting air flow control, low
water temperature starting control and high passenger compartment temperature starting control are avail-
able.
Starting Blower Speed Control
Start up from cold soak condition (Automatic mode).
In a cold start up condition where the engine coolant temperature is below 50°C (122 °F), the blower will not
operate at blower speed 1 for a short period of time (up to 210 seconds). The exact start delay time varies
depending on the ambient and engine coolant temperatures.
In the most extreme case (very low ambient temperature) the blower starting delay will be 210 seconds as
described above. After the coolant temperature reaches 50 °C (122 °F), or the 210 seconds has elapsed, the
blower speed will increase to the objective blower speed.
Start up from usual operating or hot soak condition (Automatic mode).
The blower will begin operation momentarily after the AUTO switch is pushed. The blower speed will gradually
rise to the objective speed over a time period of 3 seconds or less (actual time depends on the objective
blower speed).
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TROUBLE DIAGNOSISATC-95
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Blower Speed Compensation - Sunload
When the in-vehicle temperature and the set temperature are very close, the blower will be operating at low
speed. The speed will vary depending on the sunload. During conditions of low or no sunload, the blower
operates at low speed. During high sunload conditions, the front air control causes the blower speed to
increase.
Blower Speed Control Specification
COMPONENT DESCRIPTION
Variable Blower Control
The variable blower control is located on the cooling unit. The vari-
able blower control receives a gate voltage from the front air control
to steplessly maintain the blower motor voltage in the 0 to 5 volt
range (approx.).
DIAGNOSTIC PROCEDURE FOR BLOWER MOTOR
SYMPTOM: Blower motor operation is malfunctioning under starting
blower speed control.
WJIA0441E
WJIA0559E
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5. CHECK FRONT BLOWER MOTOR RELAY (SWITCH SIDE) CIRCUIT FOR OPEN
Check continuity between front blower motor relay harness connec-
tor M107 terminal 3 and front blower motor harness connector M62
terminal 2.
OK or NG
OK >> GO TO 6.
NG >> Repair harness or connector.
6. CHECK VARIABLE BLOWER CONTROL POWER SUPPLY CIRCUIT FOR OPEN
1. Disconnect variable blower control harness connector.
2. Check continuity between front blower motor relay harness con- nector M107 terminals 3 and variable blower control harness
connector M122 terminal 1.
OK or NG
OK >> GO TO 7.
NG >> Repair harness or connector.
7. CHECK VARIABLE BLOWER CONTROL SIGNAL CIRCUIT
1. Disconnect front air control connector.
2. Check continuity between front air control harness connector M49 terminal 13 and variable blower control harness connector
M122 terminal 2.
OK or NG
OK >> GO TO 8.
NG >> Repair harness or connector.
8. CHECK FRONT BLOWER MOTOR RELAY (COIL SIDE) POWER SUPPLY
1. Turn ignition switch ON.
2. Check voltage between front blower motor relay harness con- nector M107 terminal 2 and ground.
OK or NG
OK >> GO TO 9.
NG >> Repair harness or connector. 3 - 2
: Continuity should exist.
WJIA1360E
3 - 1: Continuity should exist.
WJIA1361E
13 - 2: Continuity should exist.
WJIA1362E
2 - Ground: Battery voltage.
WJIA1363E

ATC-98
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
9. CHECK FRONT BLOWER MOTOR RELAY (COIL SIDE) GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check continuity between front blower motor relay connector M107 terminal 1 and front air control harness connector M49 ter-
minal 26.
OK or NG
OK >> Replace front air control. Refer to ATC-144, "FRONT
AIR CONTROL" .
NG >> Repair harness or connector.
10. REPLACE FUSES
1. Replace fuses.
2. Activate the front blower motor.
3. Do fuses blow?
YES or NO
YES >> GO TO 11.
NO >> Inspection End.
11 . CHECK FRONT BLOWER MOTOR POWER SUPPLY CIRCUIT FOR SHORT
1. Turn ignition switch OFF.
2. Disconnect front blower motor connector and variable blower control connector.
3. Check continuity between variable blower control harness con- nector M122 terminal 1 and ground.
OK or NG
OK >> GO TO 12.
NG >> Repair harness or connector.
12. CHECK VARIABLE BLOWER CONTROL SIGNAL CIRCUIT
1. Disconnect front air control connector.
2. Check continuity between front air control harness connector M49 terminal 13 and variable blower control harness connector
M122 terminal 2.
OK or NG
OK >> GO TO 13.
NG >> Repair harness or connector.
13. CHECK FRONT BLOWER MOTOR
Refer to ATC-100, "
Front Blower Motor" .
OK or NG
OK >> GO TO 14.
NG >> Replace front blower motor. Refer to ATC-149, "
Removal and Installation" .
1 - 26
: Continuity should exist.
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1 - Ground.: Continuity should not exist.
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13 - 2 : Continuity should exist.
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14. CHECK BLOWER MOTOR GROUND CIRCUIT
Check continuity between front blower motor harness connector
M62 terminal 1 and variable blower control harness connector M122
terminal 3.
OK or NG
OK >> GO TO 15.
NG >> Repair harness or connector.
15. CHECK VARIABLE BLOWER CONTROL GROUND CIRCUIT
Check continuity between variable blower control harness connector
M122 terminal 4 and ground.
OK or NG
OK >> Replace variable blower control. Refer to ATC-164,
"VARIABLE BLOWER CONTROL" .
NG >> Repair harness or connector. 1 - 3 : Continuity should exist.
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4 - ground
: Continuity should exist.
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BLOWER MOTORATC-149
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Revision: November 2009 2006 QX56
BLOWER MOTORPFP:27226
ComponentsEJS003YB
Front Blower Motor
Rear Blower Motor
Removal and InstallationEJS003YC
FRONT BLOWER MOTOR
Removal
1. Remove the glove box assembly. Refer to IP-14, "Lower Instrument Panel RH and Glove Box" .
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.
LJIA0136E
1. Front heater and cooling unit assembly 2. Front blower motor 3. Variable blower control
LJIA0055E
1. Rear blower motor2. Rear blower motor case 3. Rear blower motor resistor

ATC-156
HEATER CORE
Revision: November 20092006 QX56
HEATER COREPFP:27140
ComponentsEJS003YG
Front Heater and Cooling Unit Assembly
LJIA0138E
1. Heater core cover2. Heater core pipe bracket 3. Heater core
4. Upper bracket 5. Upper heater and cooling unit case 6. A/C evaporator
7. Lower heater and cooling unit case 8. Blower motor 9. Variable blower control