service INFINITI QX56 2007 Factory Service Manual

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-61
< SERVICE INFORMATION >
C
DE
F
G H
I
K L
M A
B
AT C
N
O P
Subsequently, HOT/COLD or DEFROST/VENT or FR ESH/RECIRCULATION operation is selected. The new
door position data is returned to the front air control.
Air Mix Door Control Specification
COMPONENT DESCRIPTION
Air Mix Door Motors
The driver (1) and front passenger (2) air mix door motors are
attached to the front heater & cooling unit assembly. The rear air mix
door motor is attached to the rear heater & cooling unit. These
motors rotate so that the air mix door is opened or closed to a posi-
tion set by the front (or rear) air control. Motor rotation is then con-
veyed through a shaft and the air mix door position is then fed back
to the front air control by the PBR built into the air mix door motors.
DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR (DRIVER)
1.CHECK FRONT AIR CONTROL FOR POWER AND GROUND
WJIA1244E
WJIA0435E
WJIA2309E
WJIA1245E

ATC-62
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
1. Turn ignition switch ON.
2. Rotate temperature control dial (driver) to 32°C (90 °F).
3. Check voltage between front air control harness connector M49
terminal 3 and terminal 4 while rotating temperature control dial
(driver) to 16 °C (60 °F).
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2.CHECK AIR MIX DOOR MOTOR (DRIVE R) CIRCUITS FOR SHORT TO GROUND
1. Turn ignition switch OFF.
2. Disconnect the front air control harness connector.
3. Check continuity between front air control harness connector M49 terminal 3, 4 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-123, "Removal
and Installation" .
NG >> Repair or replace harness as necessary.
3.CHECK FRONT AIR CONTROL FOR POWER AND GROUND
1. Turn ignition switch ON.
2. Rotate temperature control dial (driver) to 32 °C (90 °F).
3. Check voltage between front air control harness connector M49
terminal 3 and terminal 4 while rotating temperature control dial
(driver) to 16 °C (60 °F).
OK or NG
OK >> GO TO 4.
NG >> Replace front air control. Refer to ATC-123, "
Removal and Installation" .
4.CHECK AIR MIX DOOR MOTOR (DRIVER) CIRCUITS FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect the front air control harness connector.
3. Check continuity between front air control harness connector M49 terminal 3 and terminal 4.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5.CHECK AIR MIX DOOR MOTOR ( DRIVER) CIRCUITS FOR OPEN
ConnectorTe r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
Front air control: M49 3 4 Rotate temp
control dial Battery
voltage
WJIA1735E
3 - Ground : Continuity should not exist.
4 - Ground : Continuity should not exist.
WJIA1736E
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
Front air control: M49 4 3
Rotate temp
control dial Battery
voltage
WJIA1737E
Continuity should exist.
WJIA1738E

TROUBLE DIAGNOSISATC-63
< SERVICE INFORMATION >
C
DE
F
G H
I
K L
M A
B
AT C
N
O P
1. Disconnect the air mix door motor (driver) harness connector.
2. Check continuity between front air control harness connector
M49 terminal 3, 4 and the air mix door motor (driver) harness
connector M147 terminal 1, 6.
OK or NG
OK >> Replace air mix door motor (driver). Refer to ATC-141,
"Removal and Installation" .
NG >> Repair or replace harness as necessary.
6.CHECK FRONT AIR CONTROL FOR PBR POWER AND GROUND
1. Reconnect front air control harness connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M49 terminal 2 and terminal 15.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7.CHECK PBR REFERENCE VOLTAGE CIRCUIT FOR SHORT TO GROUND
1. Turn ignition switch OFF.
2. Disconnect the front air control harness connector.
3. Check continuity between front air control harness connector
M49 terminal 2 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-123, "Removal
and Installation" .
NG >> Repair or replace harness as necessary.
8.CHECK PBR REFERENCE VOLT AGE AND GROUND CIRCUITS
1. Turn ignition switch OFF.
2. Disconnect the front air control harness connector.
3. Check continuity between front air control harness connector
M49 terminal 2 and terminal 15.
OK or NG
OK >> GO TO 10.
NG >> GO TO 9.
9.CHECK PBR REFERENCE VOLTAGE CIRCUIT FOR OPEN 3 - 1 : Continuity should exist.
4 - 6 : Continuity should exist.
WJIA0588E
Connector
Te r m i n a l s
Voltage (Ap-
prox.)
(+) (-)
Front air control: M49 2 15 5V
WJIA1729E
Continuity should not exist.
WJIA1730E
Continuity should exist.
WJIA1731E

ATC-64
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
1. Disconnect the air mix door motor (driver) harness connector.
2. Check continuity between air mix door motor (driver) harnessconnector M147 (B) terminal 3, 2 and front air control harness
connector M49 (A) terminal 2, 15.
OK or NG
OK >> Replace air mix door motor (driver). Refer to ATC-141,
"Removal and Installation" .
NG >> Repair or replace harness as necessary.
10.CHECK PBR FEEDBACK VOLTAGE
1. Reconnect the front air control harness connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M49 terminal 18 and ground while rotating temperature control dial
from 32 °C (90 °F) to 16 °C (60 °F).
OK or NG
OK >> GO TO 12.
NG >> GO TO 11.
11 .CHECK PBR FEEDBACK SIGNAL CIRCUIT FOR SHORT TO GROUND
1. Turn ignition switch OFF.
2. Disconnect front air control harness connector.
3. Check continuity between front air control harness connector M49 terminal 18 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-123, "Removal
and Installation".
NG >> Repair or replace harness as necessary.
12.CHECK PBR FEEDBACK CIRCUIT FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect the air mix door motor (driver) harness connector and front air control harness connector.
3. Check continuity between air mix door motor (driver) harness connector M147 terminal 4 and front air control harness connec-
tor M49 terminal 18.
OK or NG
OK >> Replace air mix door motor (driver). Refer to "DIAG- NOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR
(DRIVER)" .
NG >> Repair or replace harness as necessary.
DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR (PASSENGER)
1.CHECK FRONT AIR CONTROL FOR POWER AND GROUND 2 - 3 : Continuity should exist.
15 - 2 : Continuity should exist.
WJIA1777E
Voltage : Approx. .5V - 4.5V
LJIA0041E
Continuity should not exist.
WJIA1739E
Continuity should exist.
WJIA0590E

TROUBLE DIAGNOSISATC-65
< SERVICE INFORMATION >
C
DE
F
G H
I
K L
M A
B
AT C
N
O P
1. Turn ignition switch ON.
2. Rotate temperature control dial (passenger) to 32 °C (90 °F).
3. Check voltage between front air control harness connector M50
terminal 36 and terminal 37 while rotating temperature control
dial (passenger) to 16 °C (60 °F).
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2.CHECK AIR MIX DOOR MOTOR (PASSENG ER) CIRCUITS FOR SHORT TO GROUND
1. Turn ignition switch OFF.
2. Disconnect the front air control harness connector.
3. Check continuity between front air control harness connector
M50 terminal 36, 37 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-123, "Removal
and Installation" .
NG >> Repair or replace harness as necessary.
3.CHECK FRONT AIR CONTROL FOR POWER AND GROUND
1. Turn ignition switch ON.
2. Rotate temperature control dial (passenger) to 16 °C (60 °F).
3. Check voltage between front air control harness connector M50
terminal 36 and terminal 37 while rotating temperature control
dial (passenger) to 32 °C (90 °F).
OK or NG
OK >> GO TO 4.
NG >> Replace front air control. Refer to ATC-123, "
Removal and Installation".
4.CHECK AIR MIX DOOR MOTOR (PASSENGER) CIRCUITS FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect the front air control harness connector.
3. Check continuity between front air control harness connector
M50 terminal 36 and terminal 37.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5.CHECK AIR MIX DOOR MOTOR (P ASSENGER) CIRCUITS FOR OPEN
ConnectorTe r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
Front air control: M50 37 36 Rotate temp
control dial Battery
voltage
WJIA1740E
36 - Ground : Continuity should not exist.
37 - Ground : Continuity should not exist.
WJIA1741E
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
Front air control: M50 36 37
Rotate temp
control dial Battery
voltage
WJIA1778E
Continuity should exist.
WJIA1779E

ATC-66
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
1. Disconnect the air mix door motor (passenger) harness connec-tor.
2. Check continuity between front air control harness connector
M50 terminal 36, 37 and the air mix door motor (passenger) har-
ness connector M143 terminal 1, 6.
OK or NG
OK >> Replace air mix door motor (passenger). Refer to AT C -
141, "Removal and Installation".
NG >> Repair or replace harness as necessary.
6.CHECK FRONT AIR CONTROL FOR PBR POWER AND GROUND
1. Reconnect front air control harness connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M49 terminal 2 and terminal 15.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7.CHECK PBR REFERENCE VOLTAGE CIRCUIT FOR SHORT TO GROUND
1. Turn ignition switch OFF.
2. Disconnect the front air control harness connector.
3. Check continuity between front air control harness connector M49 terminal 2 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-123, "Removal
and Installation" .
NG >> Repair or replace harness as necessary.
8.CHECK PBR REFERENCE VOLTAGE AND GROUND CIRCUITS
1. Turn ignition switch OFF.
2. Disconnect the front air control harness connector.
3. Check continuity between front air control harness connector M49 terminal 2 and terminal 15.
OK or NG
OK >> GO TO 10.
NG >> GO TO 9.
9.CHECK PBR REFERENCE VO LTAGE CIRCUIT FOR OPEN
36 - 1 : Continuity should exist.
37 - 6 : Continuity should exist.
WJIA0548E
Connector
Te r m i n a l s
Voltage (Ap-
prox.)
(+) (-)
Front air control: M49 2 15 5V
WJIA1729E
Continuity should not exist.
WJIA1730E
Continuity should exist.
WJIA1731E

TROUBLE DIAGNOSISATC-67
< SERVICE INFORMATION >
C
DE
F
G H
I
K L
M A
B
AT C
N
O P
1. Disconnect the air mix door mo tor (passenger) harness connec-
tor.
2. Check continuity between air mix door motor (passenger) har-
ness connector M143 (B) terminal 3, 2 and front air control har-
ness connector M49 (A) terminal 2, 15.
OK or NG
OK >> Replace air mix door motor (passenger). Refer to AT C -
141, "Removal and Installation" .
NG >> Repair or replace harness as necessary.
10.CHECK PBR FEEDBACK VOLTAGE
1. Reconnect the front air control harness connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M50 terminal 41 and ground while rotating temperature control dial
(passenger) from 32 °C (90 ° F) to 16 °C (60 ° F).
OK or NG
OK >> GO TO 12.
NG >> GO TO 11.
11 .CHECK PBR FEEDBACK SIGNAL CIRCUIT FOR SHORT TO GROUND
1. Turn ignition switch OFF.
2. Disconnect front air control harness connector.
3. Check continuity between front air control harness connector
M50 terminal 41 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-123, "Removal
and Installation" .
NG >> Repair or replace harness as necessary.
12.CHECK PBR FEEDBACK CIRCUIT FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect the air mix door mo tor (passenger) harness connec-
tor and front air control harness connector.
3. Check continuity between air mix door motor (passenger) har- ness connector M143 terminal 4 and front air control harness
connector M50 terminal 41.
OK or NG
OK >> Replace air mix door motor (passenger). Refer to AT C -
141, "Removal and Installation" .
NG >> Repair or replace harness as necessary.
DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR (REAR)
1.CHECK FRONT AIR CONTROL FOR POWER AND GROUND 2 - 3 : Continuity should exist.
15 - 2 : Continuity should exist.
WJIA1777E
Voltage : Approx. .5V - 4.5V
LJIA0047E
Continuity should not exist.
WJIA1743E
Continuity should exist.
WJIA0550E

ATC-68
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
1. Turn ignition switch ON.
2. Rotate temperature control dial (rear) to maximum heat.
3. Check voltage between front air control harness connector M50terminal 27 and terminal 28 while rotating temperature control
dial (rear) to maximum cold.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2.CHECK AIR MIX DOOR MOTOR (REAR) CIRCUITS FOR SHORT TO GROUND
1. Turn ignition switch OFF.
2. Disconnect the front air control harness connector.
3. Check continuity between front air control harness connector M50 terminal 27, 28 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-123, "Removal
and Installation" .
NG >> Repair or replace harness as necessary.
3.CHECK FRONT AIR CONTROL FOR POWER AND GROUND
1. Turn ignition switch ON.
2. Rotate temperature control dial (rear) to maximum cold.
3. Check voltage between front air control harness connector M50 terminal 27 and terminal 28 while rotating temperature control
dial (rear) to maximum heat.
OK or NG
OK >> GO TO 4.
NG >> Replace front air control. Refer to ATC-123, "
Removal and Installation".
4.CHECK AIR MIX DOOR MOTOR (REAR) CIRCUITS FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect the front air control harness connector.
3. Check continuity between front air control harness connector M50 terminal 27 and terminal 28.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5.CHECK AIR MIX DOOR MOTOR (REAR) CIRCUITS FOR OPEN
ConnectorTe r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
Front air control: M50 27 28 Rotate temp
control dial Battery
voltage
WJIA1744E
27 - Ground : Continuity should not exist.
28 - Ground : Continuity should not exist.
WJIA1745E
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
Front air control: M50 28 27
Rotate temp
control dial Battery
voltage
WJIA1746E
Continuity should exist.
WJIA1747E

TROUBLE DIAGNOSISATC-69
< SERVICE INFORMATION >
C
DE
F
G H
I
K L
M A
B
AT C
N
O P
1. Disconnect the air mix door motor (rear) harness connector.
2. Check continuity between front air control harness connector
M50 terminal 27, 28 and the air mix door motor (rear) harness
connector B155 terminal 1, 6.
OK or NG
OK >> Replace air mix door motor (rear). Refer to ATC-141,
"Removal and Installation".
NG >> Repair or replace harness as necessary.
6.CHECK FRONT AIR CONTROL FOR PBR POWER AND GROUND
1. Reconnect front air control harness connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M49 terminal 2 and terminal 15.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7.CHECK PBR REFERENCE VOLTAGE CIRCUIT FOR SHORT TO GROUND
1. Turn ignition switch OFF.
2. Disconnect the front air control harness connector.
3. Check continuity between front air control harness connector
M49 terminal 2 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-123, "Removal
and Installation".
NG >> Repair or replace harness as necessary.
8.CHECK PBR REFERENCE VOLT AGE AND GROUND CIRCUITS
1. Turn ignition switch OFF.
2. Disconnect the front air control harness connector.
3. Check continuity between front air control harness connector
M49 terminal 2 and terminal 15.
OK or NG
OK >> GO TO 10.
NG >> GO TO 9.
9.CHECK PBR REFERENCE VOLTAGE CIRCUIT FOR OPEN 27 - 1 : Continuity should exist.
28 - 6 : Continuity should exist.
LJIA0049E
Connector
Te r m i n a l s
Voltage (Ap-
prox.)
(+) (-)
Front air control: M49 2 15 5V
WJIA1729E
Continuity should not exist.
WJIA1730E
Continuity should exist.
WJIA1731E