sensor INFINITI QX56 2004 Factory Service Manual

ATC-132
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
DIAGNOSTIC PROCEDURE FOR OPTICAL SENSOR
SYMPTOM: Optical sensor circuit is open or shorted. [50 (Driver) or
52 (Passenger) is indicated as a result of conducting self-diagnosis.]
1. CHECK CIRCUIT CONTINUITY BETWEEN OPTICAL SENSOR AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector M50 and optical sensor
connector M402.
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. Disconnect BCM connector M18.
2. Check continuity between optical sensor harness connector
M402 terminal 3 (P) and BCM harness connector M18 terminal
18 (P).
3. Check continuity between optical sensor harness connector
M402 terminal 3 (P) and ground.
OK or NG
OK >> Replace optical sensor. Refer to ATC-138, "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-133
C
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B
AT C
Revision: August 20072004 QX56
Intake Sensor CircuitEJS002CV
COMPONENT DESCRIPTION
Intake Sensor
The intake sensor is located on the front heater & cooling unit. It con-
verts temperature of air after it passes through the evaporator into a
resistance value which is then input to the front air control.
DIAGNOSTIC PROCEDURE FOR INTAKE SENSOR
SYMPTOM: Intake sensor circuit is open or shorted. (56 or 57 is indi-
cated as a result of conducting self-diagnosis).
1. CHECK VOLTAGE BETWEEN INTAKE SENSOR AND GROUND
1. Disconnect intake sensor connector M146.
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 M49.
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-134
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
3. CHECK INTAKE SENSOR
Refer to ATC-134, "
Intake Sensor" .
OK or NG
OK >> 1. Replace front air control. Refer to ATC-135, "FRONT AIR CONTROL" .
2. Go to self-diagnosis ATC-53, "
A/C System Self-diagnosis Function" and perform self-diagno-
sis.
NG >> 1. Replace intake sensor. Refer to ATC-139, "
INTAKE SENSOR" .
2. Go to self-diagnosis ATC-53, "
A/C System Self-diagnosis Function" and perform self-diagno-
sis.
4. CHECK CIRCUIT CONTINUITY BETWEEN INTAKE SENSOR AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49.
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-135, "FRONT AIR CONTROL" .
2. Go to self-diagnosis ATC-53, "
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-136
AMBIENT SENSOR
Revision: August 20072004 QX56
AMBIENT SENSORPFP:27722
Removal and InstallationEJS002CX
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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IN-VEHICLE SENSOR
ATC-137
C
D
E
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AT C
Revision: August 20072004 QX56
IN-VEHICLE SENSORPFP:27720
Removal and InstallationEJS002CY
REMOVAL
1. Remove the cluster lid D. Refer to IP-12, "Cluster Lid D" .
2. Remove the two screws and remove the in-vehicle sensor.
INSTALLATION
Installation is in the reverse order of removal.
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ATC-138
OPTICAL SENSOR
Revision: August 20072004 QX56
OPTICAL SENSORPFP:28576
Removal and InstallationEJS002CZ
The optical sensor is located in the top center of the instrument
panel. Refer to LT- 6 4 , "
Removal and Installation of Optical Sensor" .
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INTAKE SENSOR
ATC-139
C
D
E
F
G
H
I
K
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MA
B
AT C
Revision: August 20072004 QX56
INTAKE SENSORPFP:27723
Removal and InstallationEJS002D0
REMOVAL
1. Remove the instrument panel. Refer to IP-10, "INSTRUMENT PANEL ASSEMBLY" .
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.
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REFRIGERANT LINES
ATC-165
C
D
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AT C
Revision: August 20072004 QX56
Rear A/C
NOTE:
Refer to AT C - 7 , "
Precautions for Refrigerant Connection" .
1. High-pressure service valve 2. Grommet 3. High-pressure pipe
4. Refrigerant pressure sensor 5. Condenser 6. Compressor shaft seal
7. High-pressure flexible hose 8. Low-pressure flexible hose 9. Low-pressure service valve
10. Low-pressure pipe 11. Expansion valve (front) 12. Drain hose
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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.

REFRIGERANT LINES
ATC-173
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AT C
Revision: August 20072004 QX56
5. Remove the front and rear bumper fascia. Refer to EI-13, "FRONT BUMPER" (front), EI-15, "REAR
BUMPER" (rear).
6. Reposition the front fender protector out of the way. Refer to EI-23, "
FENDER PROTECTOR" .
7. Disconnect the chassis harness connector.
8. Remove the spare wheel and tire.
9. Remove the tailpipe and tailpipe hanger bracket. Refer to EX-3, "
Removal and Installation" .
10. Remove the seatbelt latch anchor. Refer to RSU-25, "
Components" .
11. Remove the front floor heat shield.
12. Disconnect each end of the underfloor rear high- and low-pressure A/C and heater core pipes. Refer to
ATC-164, "
Components" .
CAUTION:
Cap or wrap the joint of the pipes with suitable material such as vinyl tape to avoid the entry of air.
13. Set two suitable jacks at the RH body mount points to support the vehicle body when it is separated from
the RH side of the frame.
14. Remove the RH body mount bolts. Refer to BL-159, "
Body Mounting" .
15. Use the vehicle hoist to lower the RH side of the frame from the RH side of the body [approximately 305
mm (12 in)] until there is sufficient clearance to remove the underfloor rear high- and low-pressure A/C
and heater core pipes from between the body and the frame.
16. Remove the underfloor rear high- and low-pressure A/C and heater core pipes from the back of the vehi-
cle.
INSTALLATION
Installation is in the reverse order of removal.
Refer to ATC-164, "
Components" .
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 Refrigerant Pressure SensorEJS002DP
REMOVAL
1. Discharge the refrigerant. Refer to ATC-162, "HFC-134a (R-134a) Service Procedure" .
2. Disconnect the refrigerant pressure sensor electrical connector
and remove the refrigerant pressure sensor from the condenser.
CAUTION:
Be careful not to damage the condenser fins.
INSTALLATION
Installation is in the reverse order of removal.
Refer to ATC-164, "
Components" .
CAUTION:

Be careful not to damage the condenser fins.

Replace the O-ring of the refrigerant pressure sensor with a new one, then apply compressor oil to
it when installing it.

After charging refrigerant, check for leaks.
Removal and Installation for CondenserEJ S00 2DQ
REMOVAL
1. Discharge the refrigerant. Refer to ATC-162, "HFC-134a (R-134a) Service Procedure" .
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ATC-174
REFRIGERANT LINES
Revision: August 20072004 QX56
2. Remove the radiator. Refer to CO-10, "Removal and Installation" .
CAUTION:
Be careful not to damage the core surface of the condenser and the radiator.
3. Disconnect the high-pressure flexible hose and the high-pressure pipe from the condenser.
CAUTION:
Cap or wrap the joint of the hose and pipe with suitable material such as vinyl tape to avoid the
entry of contaminants.
4. Disconnect the refrigerant pressure sensor connector.

Remove the refrigerant pressure sensor from the condenser
as necessary.
5. Lift the condenser out of the mounting grommets to remove the
condenser.
INSTALLATION
Installation is in the reverse order of removal.
Refer to ATC-164, "
Components" .
CAUTION:

Replace the O-rings of the high-pressure pipe, refrigerant pressure sensor, and the high-pressure
flexible hose with new ones, then apply compressor oil to them after installing them.

After charging refrigerant, check for leaks.

Replace the grommets as necessary.
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