2004 INFINITI QX56 sensor

ATC-26
AIR CONDITIONER CONTROL
Revision: August 20072004 QX56
Description of Control SystemEJS002BY
The control system consists of input sensors, switches, the front air control (microcomputer) and outputs.
The relationship of these components is shown in the figure below:
Control OperationEJS002BZ
Front air control
WJIA0755E
WJIA0756E

TROUBLE DIAGNOSIS
ATC-51
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Revision: August 20072004 QX56
Front Air Control Terminals and Reference ValueEJS002C9
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
WJIA0759E
WJIA0402E
Te r m i -
nal No.Wire
colorItemIgnition
switchConditionVoltage (V)
(Approx.)
1 B Ground - - 0V
2YPower supply for each door motor
PBRON - 0 - 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 rotation Battery voltage
6 P/L Mode door motor CCW ON Counterclockwise 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 ONFan switch OFF 5V
Fan switch ON 0V
11 Y/B Rear defroster request ON - Battery voltage
12 W/R Compressor ON signal ONA/C switch OFF 5V
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 Ground for each door motor PBR ON - 0 - 5V
16 GR Mode door motor PBR feedback ON - 0 - 5V
17 P Ambient sensor ON - 0 - 5V
18 SBAir mix door motor (Driver) PBR
feedbackON - 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

ATC-52
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
21 V/R Sensor ground ON - 0 - 5V
22 Y/R Power supply for BAT - - Battery voltage
23 R/L Power supply for illumination ON Park lamps ON Battery voltage
24 BR Illumination ground - Park lamps ON
25 LG/B Defroster door motor feedback ON - 0 - 5V
26 R/B Front blower motor request ONFront 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 Counterclockwise rotation Battery voltage
29 W/G Water valve ONWater valve open 0V
Water valve closed 5V
31 W/V Optical sensor (Passenger) ON - 0 - 5V
32 LG/R In-vehicle sensor signal ON - 0 - 5V
33 V Air mix door motor (Rear) set point ON - 0 - 5V
34 W CAN-H ON - -
35 R CAN-L ON - -
36 G/W Air mix door motor (Passenger) CW ON Clockwise rotation Battery voltage
37 LAir mix door motor (Passenger)
CCWON Counter clockwise rotation Battery voltage
38 W/L Rear blower motor request ONRear blower motor OFF Battery voltage
Rear blower motor ON 0V
39 Y/B Rear select signal ON - 0 - 5V
40 G/O Optical sensor (Driver) ON - 0 - 5V
41 R/WAir mix door motor (Passenger) PBR
feedbackON - 0 - 5V
42 R/YAir mix door motor (Rear) PBR feed-
backON - 0 - 5V
43 BR/Y In-vehicle sensor motor (power) ON - Battery voltage
44 O/B In-vehicle sensor motor (ground) ON - 0V Te r m i -
nal No.Wire
colorItemIgnition
switchConditionVoltage (V)
(Approx.)
PIIA2344E

TROUBLE DIAGNOSIS
ATC-53
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Revision: August 20072004 QX56
A/C System Self-diagnosis FunctionEJS002CA
DESCRIPTION
Using Front Air Control Switches
NOTE:
Ambient temperature must be at least 10° C (50° F) to run self-diagnosis.
The self-diagnostic system diagnoses sensors, door motors, blower motor, etc. Refer to applicable sections
(items) for details. Shifting from usual control to the self-diagnostic system is accomplished by turning the igni-
tion switch ON and pressing the fan (down) switch while turning the passenger temperature dial in either direc-
tion (hold momentarily). Within 3 seconds of doing this, press the AUTO switch. The front blower speed
indication bars will flash and the ambient temperature display will indicate 0° during the self-diagnosis. Fault
codes (if any are present) will be displayed in the ambient temperature display area. Refer to AT C - 5 5 , "
SELF-
DIAGNOSIS CODE CHART" .
WJIA0837E

TROUBLE DIAGNOSIS
ATC-55
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Revision: August 20072004 QX56
SELF-DIAGNOSIS CODE CHART
Code No. Reference page
02 EE changed by calibrationATC-135, "
FRONT AIR CONTROL"
03 Battery voltage out of rangeSC-4, "BATTERY"
04 Mode switch circuit open or shortATC-135, "FRONT AIR CONTROL"
05 Blower motor malfunctionAT C - 8 3 , "Front Blower Motor Circuit"
12 Air mix door motor (Passenger) circuit malfunctionAT C - 7 1 , "DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR
MOTOR (PASSENGER)"
20 BCM not responding to A/C requestATC-104, "Magnet Clutch Circuit"
21 BCM not responding to rear defroster requestGW-78, "REAR WINDOW DEFOGGER"
22 Air mix door motor (Driver) circuit malfunctionAT C - 6 9 , "DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR
MOTOR (DRIVER)"
30 In-vehicle sensor circuit out of range (low)
ATC-128, "In-vehicle Sensor Circuit"31 In-vehicle sensor circuit out of range (high)
34 Air mix door motor (Driver) PBR circuit malfunctionAT C - 6 9 , "
DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR
MOTOR (DRIVER)"
36Air mix door motor (Passenger) PBR circuit malfunc-
tionAT C - 7 1 , "DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR
MOTOR (PASSENGER)"
38 Air mix door motor (rear) circuit malfunctionAT C - 7 3 , "DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR
MOTOR (REAR)"
40 Ambient sensor circuit short
ATC-125, "Ambient Sensor Circuit"41 Ambient sensor circuit open
44 In-vehicle sensor motor circuit open
ATC-128, "
In-vehicle Sensor Circuit"46 In-vehicle sensor motor circuit short
50 Optical sensor (Driver) circuit open or short
ATC-131, "
Optical Sensor Circuit"52 Optical sensor (Passenger) circuit open or short
56 Intake sensor circuit short
ATC-133, "
Intake Sensor Circuit"57 Intake sensor circuit open
62 Defroster door motor circuit malfunctionAT C - 7 9 , "
Defroster Door Motor Circuit"
72 Intake door motor circuit malfunctionAT C - 7 6 , "Intake Door Motor Circuit"
80 CAN bus malfunction
LAN-5, "CAN COMMUNICATION"81 CAN BCM message missing
82 Intake door motor circuit malfunctionAT C - 7 6 , "
Intake Door Motor Circuit"
90 Stuck buttonATC-135, "FRONT AIR CONTROL"
92 Mode door motor circuit malfunctionAT C - 6 3 , "Mode Door Motor Circuit"

TROUBLE DIAGNOSIS
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Revision: August 20072004 QX56
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.
Potentio Temperature Control (PTC)
There are two PTCs (passenger and driver) built into the front air
control. They can be set at an interval of 0.5°C (1.0°F) in the 18°C
(65°F) to 30°C (85°F) temperature range by rotating the temperature
dial. The set temperature is displayed.
DIAGNOSTIC PROCEDURE FOR A/C SYSTEM
SYMPTOM: A/C system does not come on.
WJIA0759E
WJIA0413E
WJIA0414E

ATC-64
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
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, defrost/floor, and defrost) is set 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 cir-
cuit of the mode door motor while ground is applied to the other circuit, causing the mode 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 control monitors the mode door position by measuring the voltage signal on the PBR
circuit.
In AUTO mode the mode door position is 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 or passenger.
Mode Door Control Specification
WJIA0959E
WJIA0965E

ATC-68
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
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 temperature 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 measuring 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.
Subsequently, HOT/COLD or DEFROST/VENT or FRESH/RECIRCULATION operation is selected. The new
door position data is returned to the front air control.
Air Mix Door Control Specification
WJIA0427E
WJIA0435E