INFINITI QX56 2006 Factory Service Manual

ATC-80
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
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-144, "
FRONT AIR CONTROL" .
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
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-163,
"REAR AIR MIX DOOR MOTOR" .
NG >> Repair or replace harness as necessary.
Connector Terminals
Condition Voltage
(Approx.)
(+) (-)
Front air control: M50 28 27
Rotate temp
control dial Battery
voltage
WJIA1746E
Continuity should exist.
WJIA1747E
27 - 1 : Continuity should exist.
28 - 6 : Continuity should exist.
LJIA0049E

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Revision: November 2009 2006 QX56
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-144, "FRONT
AIR CONTROL" .
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 VOLTAGE CIRCUIT FOR OPEN
1. Disconnect the air mix door motor (rear) harness connector.
2. Check continuity between air mix door motor (rear) harness con- nector B155 (B) terminal 3, 2 and front air control harness con-
nector M49 (A) terminal 2, 15.
OK or NG
OK >> Replace air mix door motor (rear). Refer to ATC-163,
"REAR AIR MIX DOOR MOTOR" .
NG >> Repair or replace harness as necessary.
Connector Te r m i n a l s
Voltage
(Approx.)
(+) (-)
Front air control: M49 2 15 5V
WJIA1729E
Continuity should not exist.
WJIA1730E
Continuity should exist.
WJIA1731E
2 - 3 : Continuity should exist.
15 - 2 : Continuity should exist.
WJIA1748E

ATC-82
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
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 42 and ground while rotating temperature control dial
(rear) from maximum cold to maximum heat.
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 42 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-144, "FRONT
AIR CONTROL" .
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 (rear) harness connector and front air control harness connector.
3. Check continuity between air mix door motor (rear) harness con- nector B155 terminal 4 and front air control harness connector
M50 terminal 42.
OK or NG
OK >> Replace air mix door motor (rear). Refer to ATC-163,
"REAR AIR MIX DOOR MOTOR" .
NG >> Repair or replace harness as necessary. Voltage : Approx. 1V - 4.5V
LJIA0053E
Continuity should not exist.
WJIA1749E
Continuity should exist.
LJIA0054E

TROUBLE DIAGNOSISATC-83
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Revision: November 2009 2006 QX56
Intake Door Motor CircuitEJS003XQ
SYMPTOM:

Intake door does not change.

Intake door motor does not operate normally.
INSPECTION FLOW
*1ATC-58, "Operational Check (Front)"*2ATC-56, "A/C System Self-diagno-
sis Function"
*3 ATC-57, "SELF-DIAGNOSIS CODE
CHART"
WJIA1440E

ATC-84
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
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 position 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.
In the AUTO mode, the front air control determines the intake door position based on the ambient tempera-
ture, the intake air temperature and the in-vehicle temperature. When the DEF, D/F, FLOOR or OFF switches
are pushed, the front air control sets the intake door at the fresh position.
Intake Door Control Specification
WJIA1915E
WJIA0436E

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COMPONENT DESCRIPTION
Intake door motor
The intake door motor is attached to the intake unit assembly. It
rotates so that air is drawn from inlets set by the front air control.
Motor rotation is conveyed to a lever which activates the intake door.
DIAGNOSTIC PROCEDURE FOR INTAKE DOOR MOTOR
1. CHECK FRONT AIR CONTROL FOR POWER AND GROUND
1. Turn ignition switch ON.
2. Check voltage between front air control harness connector M49 terminal 7 and terminal 8 while placing the HVAC system into
self-diagnostic mode.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. CHECK INTAKE DOOR MOTOR 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 7, 8 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-144, "FRONT
AIR CONTROL" .
NG >> Repair or replace harness as necessary.
WJIA0552E
Connector Terminals
Condition Voltage
(Approx.)
(+) (-)
Front air control: M49 7 8
Self-diagnostic
mode Battery
voltage
WJIA1757E
7 - Ground : Continuity should not exist.
8 - Ground : Continuity should not exist.
WJIA1758E

ATC-86
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
3. CHECK FRONT AIR CONTROL FOR GROUND AND POWER
1. Press the BACK button to back out of self-diagnostic mode.
2. Check voltage between front air control harness connector M49 terminal 7 and terminal 8 while placing the HVAC system into
self-diagnostic mode.
OK or NG
OK >> GO TO 4.
NG >> Replace front air control. Refer to ATC-144, "
FRONT AIR CONTROL" .
4. CHECK INTAKE DOOR MOTOR AND 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 7 and terminal 8.
OK or NG
OK >> Replace intake door motor. Refer to ATC-160, "Removal
and Installation" .
NG >> GO TO 5.
5. CHECK INTAKE DOOR MOTOR CIRCUITS FOR OPEN
1. Disconnect the intake door motor harness connector.
2. Check continuity between front air control harness connector M49 terminal 7, 8 and the intake door motor harness connector
M58 terminal 1, 6.
OK or NG
OK >> Replace intake door motor. Refer to ATC-160, "Removal
and Installation" .
NG >> Repair or replace harness as necessary.
Connector Terminals
Condition Voltage
(Approx.)
(+) (-)
Front air control: M49 8 7 Self-diagnostic
mode Battery
voltage
WJIA1759E
Continuity should exist.
WJIA1760E
1 - 7 : Continuity should exist.
6 - 8 : Continuity should exist.
WJIA0591E

TROUBLE DIAGNOSISATC-87
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Revision: November 2009 2006 QX56
Defroster Door Motor CircuitEJS003XR
SYMPTOM:

Defroster door does not change.

Defroster door motor does not operate normally.
INSPECTION FLOW
*1AT C - 5 8 , "Operational Check
(Front)"*2
ATC-87, "Defroster Door Motor Circuit"*3ATC-144, "FRONT AIR CONTROL"
*4 ATC-159, "DEFROSTER DOOR
MOTOR"
WJIA1921E

ATC-88
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
SYSTEM DESCRIPTION
Component Parts
Defroster door control system components are:

Front air control

Defroster door motor

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 motor rotates directing air to the defroster ducts. When any
mode other than defroster is selected, the defroster motor 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.
WJIA1354E
WJIA0592E

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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.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. CHECK DEFROSTER DOOR MOTOR 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 19, 20 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-144, "FRONT
AIR CONTROL" .
NG >> Repair or replace harness as necessary.
3. CHECK FRONT AIR CONTROL FOR GROUND AND POWER
1. Press the defroster switch ( ).
2. Check voltage between front air control harness connector M49 terminal 19 and terminal 20 and press the defroster switch ( )
again.
OK or NG
OK >> GO TO 4.
NG >> Replace front air control. Refer to ATC-144, "
FRONT AIR CONTROL" .
ConnectorTerminals
Condition Voltage
(Approx.)
(+) (-)
Front air control: M49 20 19 Press
defroster
switch Battery
voltage
WJIA1765E
19 - Ground : Continuity should not exist.
20 - Ground : Continuity should not exist.
WJIA1766E
Connector Terminals
Condition Voltage
(Approx.)
(+) (-)
Front air control: M49 19 20 Press
defroster switch Battery
voltage
WJIA1767E