2007 INFINITI QX56 sensor

TROUBLE DIAGNOSISATC-47
< SERVICE INFORMATION >
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Front Air Control Termina l and Reference ValueINFOID:0000000003533247
Measure voltage between each terminal and ground by following
Terminals and Reference Value for front air control.
FRONT HARNESS CONNECTOR TERMINAL LAYOUT
TERMINALS AND REFERENCE VALUES FOR FRONT AIR CONTROL
WJIA0544E
WJIA2010E
Te r m i n a l
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 Coun terclockwise rotation Battery voltage
5 BR/W Mode door motor CW ON Clockwise rotation Battery voltage
6 P/L Mode door motor CCW ON Counterclockw ise rotation Battery voltage
7 O Intake door motor CCW ON Counterclockwise rotation Battery voltage
8 G/B Intake door motor CW ON Clockwise rotation Battery 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 requ est 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 (D river) feedback ON - 0 - 5V
19 LG Defroster door motor CW ON Clockwise rotation Battery voltage
20 P/B Defroster door motor CCW ON Counterclockwise rotation Battery voltage
21 V/R Sensor return ON - 0 - 5V

ATC-48
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
A/C System Self-Diagnosis Function
INFOID:0000000003533248
DESCRIPTION
22 Y/R Power supply for BAT - - Battery voltage
23 R/L Illumination + ON Park lamps ON Battery voltage
24 BR Illumination - - Park lamps ON
25 LG/B Defroster door motor feedback ON - 0 - 5V
26 R/B Front blower request ON Front blower motor OFF Battery voltage
Front blower motor ON 0V
27 GR/R Air mix door motor (Rear) CW ON Clockwise rotation Battery voltage
28 L/Y Air mix door motor (Rear) CCW ON Coun terclockwise rotation Battery voltage
29 Y/L Water valve ON Water valve open 0V
Water valve closed 5V
30 W/G Water valve ON Water valve open 0V
Water valve closed Battery voltage
31 W/V Optical sensor (Passenger) ON - 0 - 5V
32 LG/R In-vehicle sensor signal ON - 0 - 5V
33 V Air mix door (Rear) set point ON - 0 - 5V
34 L CAN-H ON - 0 - 5V
35 P CAN-L ON - 0 - 5V
36 G/W Air mix door motor (Passenger) CW ON Clockwise rotation Battery voltage
37 L Air mix door motor (Passenger)
CCW ON Counter clockwise rotation Battery voltage
38 W/L Rear blower request ON Front blower motor OFF Battery voltage
Front blower motor ON 0V
39 Y/B Rear select signal ON - 0V - Battery voltage
40 G/O Optical sensor (Driver) ON - 0 - 5V
41 R/W Air mix door motor (Passenger) feed-
back ON - 0 - 5V
42 R/Y Air mix door motor (Rear) feedback ON - 0 - 5V
43 BR/Y In-vehicle sensor motor (+) ON - Battery voltage
44 O/B In-vehicle sensor motor (-) ON - 0V
Te r m i n a l
No. Wire
color ItemIgnition
switch Condition Voltage (V)
(Approx.)
PIIA2344E

TROUBLE DIAGNOSISATC-49
< SERVICE INFORMATION >
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The self-diagnostic system diagnoses sensors, door motors, blower motor, etc. Refer to applicable sections
(items) for details. Fault codes (if any are present) wil l be displayed in the ambient temperature display area.
Refer to "SELF-DIAGNOSIS CODE CHART" .
SELF-DIAGNOSIS CODE CHART
WJIA1913E
Code No. Reference page
02 EE changed by calibration ATC-123, "
Removal and Installation"
03 Battery voltage out of rangeSC-4
12 Air mix door motor (Passenger) circuit failureAT C - 5 9 , "Air Mix Door Motor Circuit"
20 BCM not responding to A/C requestAT C - 9 6 , "Magnet Clutch Circuit"
21 BCM not responding to rear defroster requestGW-68
22 Air mix door motor (Driver) circuit failure AT C - 5 9 , "Air Mix Door Motor Circuit"
30 In-vehicle sensor circuit out of range (low)
AT C - 11 6 , "In-vehicle Sensor Circuit"31 In-vehicle sensor circuit out of range (high)
38 Air mix door motor (rear) circuit failure AT C - 5 9 , "
Air Mix Door Motor Circuit"
40 Ambient sensor circuit short
AT C - 11 4 , "Ambient Sensor Circuit"41 Ambient sensor circuit open
44 In-vehicle sensor motor circuit openATC-120, "
Intake Sensor Circuit"46 In-vehicle sensor motor circuit short
50 Optical sensor (Driver) circuit open or shortAT C - 11 9 , "
Optical Sensor Circuit"52 Optical sensor (Passenger) circuit open or short
56 Intake sensor circuit shortATC-120, "
Intake Sensor Circuit"57 Intake sensor circuit open
62 Defroster door motor circuit failureAT C - 7 4 , "
Defroster Door Motor Circuit"
80 CAN bus faultLAN-4, "CAN Communication System"
82 Intake door motor (d river) circuit malfunction AT C - 7 0 , "Intake Door Motor Circuit"

ATC-52
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
If NG, listen for sound of air mix door motor operation if OK, go to trouble diagnosis procedure for ATC-100,
"Insufficient Cooling" . If air mix door motor appears to be malfunctioning, go to ATC-59, "Air Mix Door Motor
Circuit".
If OK, continue the check.
CHECKING TEMPERATURE INCREASE
1. Rotate temperature and mode dial clockwise.
2. Check for hot air at appropriate discharge air outlets.
If NG, listen for sound of air mix door motor operat ion. If OK, go to trouble diagnosis procedure for ATC-108,
"Insufficient Heating". If air mix door motor appears to be malfunctioning, go to ATC-59, "Air Mix Door Motor
Circuit" .
If OK, continue the check.
Power Supply and Ground Circu it for Front Air ControlINFOID:0000000003533251
SYMPTOM: A/C system does not come on.
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK - AUTO MODE
1. Press AUTO switch.
2. Display should indicate AUTO. Confirm that the compressor clutch engages (sound or visual inspection).
(Discharge air and blower speed will depend on am bient, in-vehicle and set temperatures.)
Can a symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2.PERFORM COMPLETE OPERATIONAL CHECK
Perform a complete operational check and check for any symptoms. Refer to ATC-50, "
Operational Check
(Front)".
Can a symptom be duplicated
YES >> Refer to ATC-32, "How to Perform Trouble Diagnosis for Quick and Accurate Repair".
NO >> System OK.
3.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 4.
4.CHECK POWER AND GROUND CIRCUIT
Check main power supply and ground circuit. Refe r to "DIAGNOSTIC PROCEDURE FOR A/C SYSTEM".
OK or NG
OK >> System OK.
NO >> Replace front air control. Refer to ATC-123, "
Removal and Installation".
COMPONENT DESCRIPTION
Front Air Control
The front air control has a built-in microcomputer which processes
information sent from various sensors needed for air conditioner
operation. The air mix door motors, mode door motor, intake door
motor, defroster door motor, blower motor and compressor are then
controlled.
The front air control is unitized with control mechanisms. When the
various switches and temperature dials are operated, data is input to
the front air control.
Self-diagnostic functions are also built into the front air control to pro-
vide quick check of malfunctions in the auto air conditioner system.
WJIA0544E

TROUBLE DIAGNOSISATC-55
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Perform diagnostic procedure for the mode door moto r. Refer to "DIAGNOSTIC PROCEDURE FOR MODE
DOOR MOTOR".
OK or NG
OK >> GO TO 7.
NG >> Repair PBR circuit or replace motor.
7.RECHECK FOR CODES
Perform self-diagnosis. Refer to ATC-48, "
A/C System Self-Diagnosis Function" .
Are any self-diagnostic codes present?
YES >> Refer to ATC-48, "A/C System Self-Diagnosis Function" .
NO >> GO TO 8.
8.RECHECK FOR SYMPTOMS
Perform a complete operational check and check for any symptoms. Refer to ATC-50, "
Operational Check
(Front)" .
Does another symptom exist?
YES >> Repair as necessary.
NO >> Replace front air control. Refer to ATC-123, "
Removal and Installation" .
SYSTEM DESCRIPTION
Component Parts
Mode door control system components are:• Front air control
• Mode door motor
• PBR (built into mode door motor)
• In-vehicle sensor
• Ambient sensor
• Optical sensor
• Intake sensor
System Operation
The mode door position (vent, B/L, foot, and defrost) is se t by the front air control by means of the mode door
motor. When a mode door position is selected on the front air control, voltage is applied to one circuit of the
mode door motor while ground is applied to the other circui t, causing the mode door motor to rotate. The direc-
tion of rotation is determined by which circuit has voltage applied to it, and which one has ground applied to it.
The front air control monitors the mode door positi on by measuring the voltage signal on the PBR circuit.
In AUTO mode the mode door position is set by the fr ont air control which determines the proper position
based on inputs from the in-vehicle sens or, ambient sensor, optical sensor, intake sensor, and the temperature
selected by the driver or passenger.
WJIA1240E

ATC-60
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
5.CHECK AIR MIX DOOR OPERATION
Check and verify air mix door mechanism for smooth operation from 16 °C (60 °F) to 32 °C (90 °F) in each
mode.
OK or NG
OK >> GO TO 6.
NG >> Repair as necessary.
6.PERFORM SELF-DIAGNOSIS
Perform self-diagnosis to check for any codes. Refer to ATC-48, "
A/C System Self-Diagnosis Function" .
Are any self-diagnosis codes present?
YES >> Refer to ATC-48, "A/C System Self-Diagnosis Function" .
NO >> GO TO 7.
7.CHECK THE AIR MIX DOOR MOTOR PBR CIRCUIT
Perform diagnostic procedure for the air mix door motors. Refer to "Air Mix Door Motor Circuit" .
OK or NG
OK >> GO TO 8.
NG >> Repair PBR circuit or replace air mix door motor. Refer to ATC-141
.
8.RECHECK FOR CODES
Perform self-diagnosis. Refer to ATC-48, "
A/C System Self-Diagnosis Function" .
Are any self-diagnostic codes present?
YES >> Refer to ATC-48, "A/C System Self-Diagnosis Function" .
NO >> GO TO 9.
9.RECHECK FOR ANY SYMPTOMS
Perform a complete operational check for any symptoms. Refer to ATC-50, "
Operational Check (Front)".
Does another symptom exist?
YES >> Refer to ATC-32, "How to Perform Trouble Diagnosis for Quick and Accurate Repair" .
NO >> Replace front air control. Refer to ATC-123, "
Removal and Installation".
SYSTEM DESCRIPTION
Component Parts
Air mix door control system components are:
• Front air control.
• Air mix door motors (Driver, Passenger, and rear)
• PBR (built-into air mix door motors)
• In-vehicle sensor
• Ambient sensor
• Optical sensor
• Intake sensor
System Operation
The front air control receives data from the temperatur e selected by the driver side, passenger side, and rear.
The front air control then applies a voltage to one circuit of the appropriate air mix door motor, while ground is
applied to the other circuit, causing the appropriate air mix door motor to rotate. The direction of rotation is
determined by which circuit has voltage applied to it, and which one has ground applied to it. The front air con-
trol monitors the air mix door positions by measur ing the voltage signal on the PBR circuits of each door.
In AUTO mode the air mix, intake, mode door, and defrost door positions are set by the front air control which
determines the proper position based on inputs from the in-vehicle sensor, ambient sensor, optical sensor,
intake sensor, and the temperature selected by the driver and front and rear passengers.

TROUBLE DIAGNOSISATC-71
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INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK - REC ( )
1. Press the mode switch to vent mode( ).
2. Press REC ( ) switch. The REC ( ) icon should illuminate on display.
3. Press REC ( ) switch again. The REC ( ) icon should go out on the display.
4. Listen for intake door position change (you should hear blower sound changes slightly).
Can a symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2.PERFORM COMPLETE OPERATIONAL CHECK
Perform a complete operational check and check for any symptoms. Refer to ATC-50, "
Operational Check
(Front)" .
Can a symptom be duplicated?
YES >> Refer to ATC-32, "How to Perform Trouble Diagnosis for Quick and Accurate Repair".
NO >> System OK.
3.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 4.
4.CHECK INTAKE DOOR OPERATION
Check and verify intake door me chanism for smooth operation.
OK or NG
OK >> GO TO 5.
NG >> Repair intake door mechanism.
5.PERFORM SELF-DIAGNOSIS
Perform self-diagnosis to check for any codes. Refer to ATC-48, "
A/C System Self-Diagnosis Function" .
Are any self-diagnosis codes present?
YES >> Refer to ATC-48, "A/C System Self-Diagnosis Function" .
NO >> GO TO 6.
6.RECHECK FOR ANY SYMPTOMS
Perform a complete operational check for any symptoms. Refer to ATC-50, "
Operational Check (Front)" .
Does another symptom exist?
YES >> Refer to ATC-32, "How to Perform Trouble Diagnosis for Quick and Accurate Repair" .
NO >> Replace front air control. Refer to ATC-123, "
Removal and Installation".
SYSTEM DESCRIPTION
Component Parts
Intake door control system components are:• Front air control
• Intake door motor
• In-vehicle sensor
• Ambient sensor
• Optical sensor
• Intake sensor
System Operation
The intake door control determines the intake door posit ion based on the position of the recirculation switch.
When the recirculation switch is depressed the intake door motor rotates closing off the fresh air inlet and
recirculating the cabin air. If the recirculation switch is depressed again, the intake door motor rotates in the
opposite direction, again allowing fresh air into the cabin.

TROUBLE DIAGNOSISATC-75
< SERVICE INFORMATION >
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• PBR (Built into defroster door motor)
• In-vehicle sensor
• Ambient sensor
• Optical sensor
• Intake sensor
System Operation
The front air control determines defroster door position based on the position of the defroster switch. When the
defroster switch is depressed, the defroster door moto r rotates directing air to the defroster ducts. When any
mode other than defroster is selected, the defroster moto r rotates in the opposite direction closing off air flow
to the defroster ducts.
In the AUTO mode, the front air control determines defroster door position based on the ambient temperature,
the intake air temperature and the in-vehicle temperature.
COMPONENT DESCRIPTION
Defroster door motor
The defroster door motor is attached to the front heater & cooling
unit assembly. The front air control sends a voltage to rotate to the
defroster door directing the air flow either to the defroster ducts, or to
the floor ducts, depending on which way the voltage and ground are
applied to the motor leads. Motor rotation is conveyed to a lever
which activates the defroster door.
DIAGNOSTIC PROCEDURE FOR DEFROSTER DOOR MOTOR
1.CHECK FRONT AIR CONTROL FOR POWER AND GROUND
1. Turn ignition switch ON.
2. Press the defroster switch ( ).
3. Check voltage between front air control harness connector M49 terminal 20 and terminal 19 and press the defroster switch ( )
again.
WJIA1354E
WJIA0592E
WJIA2277E