2005 INFINITI QX4 sensor

ATC-140
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
In-vehicle Sensor CircuitEJS003Y3
COMPONENT DESCRIPTION
In-vehicle Sensor
The in-vehicle sensor is located on instrument lower driver panel. It
converts variations in temperature of passenger compartment air
(drawn in through the integrated fan) into a resistance value. It is
then input into the front air control.
WJIA0822E
WJIA0606E

TROUBLE DIAGNOSIS
ATC-141
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Revision: October 20052005 QX56
DIAGNOSTIC PROCEDURE FOR IN-VEHICLE SENSOR
SYMPTOM: in-vehicle sensor circuit is open or shorted. Using the
CONSULT-II, DTC B2578 or B2579 is displayed. Without a CON-
SULT-II, code 30 or 31 is indicated on front air control as a result of
conducting the front air control self-diagnosis.
1. CHECK IN-VEHICLE SENSOR CIRCUIT
Are diagnostic codes 30, 31 or DTC B2578, B2579 present?
YES or NO
YES >> GO TO 6.
NO >> GO TO 2.
2. CHECK VOLTAGE BETWEEN IN-VEHICLE SENSOR AND GROUND
1. Disconnect in-vehicle sensor connector.
2. Turn ignition switch ON.
3. Check voltage between in-vehicle sensor harness connector
M32 terminal 4 (LG/R) and ground.
OK or NG
OK >> GO TO 3.
NG >> GO TO 5.
3. CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49.
3. Check continuity between in-vehicle sensor harness connector
M32 terminal 1 (V/R) and front air control harness connector
M49 terminal 21 (V/R).
OK or NG
OK >> GO TO 4.
NG >> Repair harness or connector.
4. CHECK IN-VEHICLE SENSOR
Refer to ATC-145, "
Intake Sensor Circuit" .
OK or NG
OK >> 1. Replace front air control. Refer to ATC-147, "FRONT AIR CONTROL" .
2. Go to AT C - 5 5 , "
A/C System Self-diagnosis Function" and perform self-diagnosis.
NG >> 1. Replace in-vehicle sensor. Refer to ATC-149, "
IN-VEHICLE SENSOR" .
2. Go to AT C - 5 5 , "
A/C System Self-diagnosis Function" and perform self-diagnosis.
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4 - Ground : Approx. 5V.
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1 - 21 : Continuity should exist.
LJIA0090E

ATC-142
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
5. CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector.
3. Check continuity between in-vehicle sensor harness connector
M32 terminal 4 (LG/R) and front air control harness connector
M50 terminal 32 (LG/R).
4. Check continuity between in-vehicle sensor harness connector
M32 terminal 4 (LG/R) and ground.
OK or NG
OK >> 1. Replace front air control. Refer to ATC-147, "FRONT AIR CONTROL" .
2. Go to self-diagnosis AT C - 5 5 , "
A/C System Self-diagnosis Function" and perform self-diagno-
sis.
NG >> Repair harness or connector.
6. CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR MOTOR AND FRONT AIR CON-
TROL (SELF-DIAGNOSIS CODES 44, 46 OR DTC B2578, 2579)
1. Turn ignition switch OFF.
2. Disconnect front air control connector and in-vehicle sensor con-
nector.
3. Check continuity between in-vehicle sensor harness connector
M32 terminal 2 (O/B) and 3 (BR/Y) and front air control harness
connector M50 terminal 44 (O/B) and 43 (BR/Y).
4. Check continuity between in-vehicle sensor harness connector
M32 terminal 2 (O/B) and 3 (BR/Y) and ground.
OK or NG
OK >> 1. Replace front air control. Refer to ATC-147, "FRONT AIR CONTROL" .
2. Go to ATC-55, "
A/C System Self-diagnosis Function" and perform self-diagnosis.
NG >> Repair harness or connector.4 - 32 : Continuity should exist.
4 - Ground Continuity should not exist.
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2 - 44 : Continuity should exist.
3 - 43 : Continuity should exist.
2, 3 - Ground :Continuity should not exist.
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TROUBLE DIAGNOSIS
ATC-143
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Revision: October 20052005 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
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WJIA0569E

ATC-144
TROUBLE DIAGNOSIS
Revision: October 20052005 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 51 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 (W/V) and 2 (G/O) and front air control harness
connector M50 terminal 31 (W/V) and 40 (G/O).
4. Check continuity between optical sensor harness connector
M402 terminal 1 (W/V) and 2 (G/O) 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 (P) and BCM harness connector M18 terminal
18 (P).
4. Check continuity between optical sensor harness connector
M402 terminal 3 (P) and ground.
OK or NG
OK >> Replace optical sensor. Refer to ATC-150, "OPTICAL SENSOR" .
NG >> Repair harness or connector.
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1 - 31 : Continuity should exist.
2 - 40 : Continuity should exist.
1, 2 - Ground. : Continuity should not exist.
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3 - 18 : Continuity should exist.
3 - Ground : Continuity should not exist.
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TROUBLE DIAGNOSIS
ATC-145
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Revision: October 20052005 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 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 (L/B) 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 (V/R) and front air control harness connector
M49 terminal 21 (V/R).
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
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2 - Ground : Approx. 5V
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1 - 21 : Continuity should exist.
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ATC-146
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
3. CHECK INTAKE SENSOR
Refer to ATC-146, "
Intake Sensor" .
OK or NG
OK >> 1. Replace front air control. Refer to ATC-147, "FRONT AIR CONTROL"
2. Go to self-diagnosisAT C - 5 5 , "A/C System Self-diagnosis Function" and perform self-diagnosis.
NG >> 1. Replace intake sensor. Refer to ATC-151, "
INTAKE SENSOR" .
2. Go to self-diagnosisAT C - 5 5 , "
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 (L/B) and front air control harness connector
M49 terminal 9 (L/B).
4. Check continuity between intake sensor harness connector
M146 terminal 2 (L/B) and ground.
OK or NG
OK >> 1. Replace front air control. Refer to ATC-147, "FRONT AIR CONTROL" .
2. Go to self-diagnosis AT C - 5 5 , "
A/C System Self-diagnosis Function" and perform self-diagno-
sis.
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.
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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
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ATC-148
AMBIENT SENSOR
Revision: October 20052005 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.
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