INFINITI QX56 2006 Factory Service Manual

ATC-140
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
COMPONENT INSPECTION
In-vehicle Sensor
After disconnecting in-vehicle sensor connector M32, measure resis-
tance between terminals 1 and 4 at sensor component side, using
the table below.
If NG, replace in-vehicle sensor.
Optical Sensor CircuitEJS003Y4
COMPONENT DESCRIPTION
The optical sensor is located in the center of the defroster grille. It
detects sunload entering through windshield by means of a photo
diode. The sensor converts the sunload into a current value which is
then input into the front air control.
OPTICAL INPUT PROCESS
The front air control includes a processing circuit which averages the variations in detected sunload over a
period of time. This prevents adjustments in the ATC system operation due to small or quick variations in
detected sunload.
For example, consider driving along a road bordered by an occasional group of large trees. The sunload
detected by the optical sensor will vary whenever the trees obstruct the sunlight. The processing circuit aver-
ages the detected sunload over a period of time, so that the (insignificant) effect of the trees momentarily
obstructing the sunlight does not cause any change in the ATC system operation. On the other hand, shortly
after entering a long tunnel, the system will recognize the change in sunload, and the system will react accord-
ingly.
Temperature °C (°F) Resistance kΩ
− 15 (5) 21.40
− 10 (14) 16.15
− 5 (23) 12.29
0 (32) 9.41
5 (41) 7.27
10 (50) 5.66
15 (59) 4.45
20 (68) 3.51
25 (77) 2.79
30 (86) 2.24
35 (95) 1.80
40 (104) 1.45
45 (113) 1.18
WJIA0825E
WJIA0569E

TROUBLE DIAGNOSISATC-141
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AT C
Revision: November 2009 2006 QX56
DIAGNOSTIC PROCEDURE FOR OPTICAL SENSOR
SYMPTOM: Optical sensor circuit is open or shorted. Using the
CONSULT-II, DTC B257F or B2580 is displayed. Without a CON-
SULT-II, code 50 or 52 is indicated on front air control as a result of
conducting the front air control self-diagnosis.
1. CHECK CIRCUIT CONTINUITY BETWEEN OPTICAL SENSOR AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector and optical sensor con- nector.
3. Check continuity between optical sensor harness connector M402 terminal 1 and 2 and front air control harness connector
M50 terminal 31 and 40.
4. Check continuity between optical sensor harness connector M402 terminal 1 and 2 and ground.
OK or NG
OK >> GO TO 2.
NG >> Repair harness or connector.
2. CHECK CIRCUIT CONTINUITY BETWEEN OPTICAL SENSOR AND BCM
1. Turn ignition switch OFF.
2. Disconnect BCM connector and optical sensor connector.
3. Check continuity between optical sensor harness connector M402 terminal 3 and BCM harness connector M18 terminal 18.
4. Check continuity between optical sensor harness connector M402 terminal 3 and ground.
OK or NG
OK >> Replace optical sensor. Refer to ATC-147, "OPTICAL SENSOR" .
NG >> Repair harness or connector.
WJIA0570E
1 - 31 : Continuity should exist.
2 - 40 : Continuity should exist.
1, 2 - Ground. : Continuity should not exist.
WJIA1445E
3 - 18 : Continuity should exist.
3 - Ground : Continuity should not exist.
WJIA1446E

ATC-142
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
Intake Sensor CircuitEJS003Y5
COMPONENT DESCRIPTION
Intake Sensor
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 displayed. 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 INTAKE 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.
WJIA0571E
WJIA0464E
2 - Ground : Approx. 5V
WJIA1375E
1 - 21 : Continuity should exist.
WJIA1376E

TROUBLE DIAGNOSISATC-143
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Revision: November 2009 2006 QX56
3. CHECK INTAKE SENSOR
Refer to ATC-143, "
Intake Sensor" .
OK or NG
OK >> 1. Replace front air control. Refer to ATC-144, "FRONT AIR CONTROL"
2. Go to AT C - 5 6 , "A/C System Self-diagnosis Function" and perform self-diagnosis.
NG >> 1. Replace intake sensor. Refer to ATC-148, "
INTAKE SENSOR" .
2. Go to AT C - 5 6 , "
A/C System Self-diagnosis Function" and perform self-diagnosis.
4. CHECK CIRCUIT CONTINUITY BETWEEN INTAKE 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 2 and front air control harness connector M49 ter-
minal 9.
4. Check continuity between intake sensor harness connector M146 terminal 2 and ground.
OK or NG
OK >> 1. Replace front air control. Refer to ATC-144, "FRONT AIR CONTROL" .
2. Go to AT C - 5 6 , "
A/C System Self-diagnosis Function" and perform self-diagnosis.
NG >> Repair harness or connector.
COMPONENT INSPECTION
Intake Sensor
After disconnecting intake sensor connector, measure resistance
between terminals 1 and 2 at sensor harness side, using the table
below.
If NG, replace intake sensor. 2 - 9
: Continuity should exist.
2 - Ground : Continuity should not exist.
WJIA1377E
Temperature °C ( °F) Resistance kΩ
− 15 (5) 209.0
− 10 (14) 160.0
− 5 (23) 123.0
0 (32) 95.8
5 (41) 74.9
10 (50) 58.9
15 (59) 46.7
20 (68) 37.3
25 (77) 30.0
30 (86) 24.2
35 (95) 19.7
40 (104) 16.1
45 (113) 13.2
WJIA1378E

ATC-144
CONTROL UNIT
Revision: November 20092006 QX56
CONTROL UNITPFP:27500
Removal and InstallationEJS003Y6
FRONT AIR CONTROL
Removal
1. Remove the five control knobs from the front air control unit.
2. Remove the cluster lid C. Refer to IP-12, "
Removal" .
3. Remove the four screws securing the front air control unit to cluster lid C.
4. Remove the front air control unit.
Installation
Installation is in the reverse order of removal.
REAR AIR CONTROL
Removal
1. Remove the overhead console from the headliner. Refer to EI-38, "HEADLINING" .
2. Remove the four screws and remove the rear air control.
Installation
Installation is in the reverse order of removal.
LJIA0130E
LJIA0131E

AMBIENT SENSORATC-145
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M A
B
AT C
Revision: November 2009 2006 QX56
AMBIENT SENSORPFP:27722
Removal and InstallationEJS003Y7
REMOVAL
1. Disconnect the ambient sensor electrical connector.
NOTE:
The ambient sensor is located behind the front bumper, in front
of the condenser.
2. Release the ambient sensor clip and then remove the ambient sensor.
INSTALLATION
Installation is in the reverse order of removal.
WJIA0819E

ATC-146
IN-VEHICLE SENSOR
Revision: November 20092006 QX56
IN-VEHICLE SENSORPFP:27720
Removal and InstallationEJS003Y8
REMOVAL
1. Remove the cluster lid D. Refer to IP-12, "Removal" .
2. Remove the two screws and remove the in-vehicle sensor from cluster lid D.
INSTALLATION
Installation is in the reverse order of removal.
LJIA0132E

OPTICAL SENSORATC-147
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AT C
Revision: November 2009 2006 QX56
OPTICAL SENSORPFP:28576
Removal and InstallationEJS003Y9
The optical sensor is located in the top center of the instrument
panel. Refer to LT- 6 4 , "
Optical Sensor" .
WJIA0607E

ATC-148
INTAKE SENSOR
Revision: November 20092006 QX56
INTAKE SENSORPFP:27723
Removal and InstallationEJS003YA
REMOVAL
1. Remove the glove box assembly. Refer to IP-15, "Glove Box" .
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

BLOWER MOTORATC-149
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AT C
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