2006 INFINITI QX56 blower motor

ATC-110
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
COMPONENT INSPECTION
Rear Blower Motor Relay
Check circuit continuity between terminals by supplying 12 volts and
ground to coil side terminals of relays.
Rear Blower Switch (Rear)
Check continuity between terminals at each switch position.
Rear Blower Switch (Front)
Check continuity between terminals at each switch position.
WJIA0973E
LJIA0113E
LJIA0114E

TROUBLE DIAGNOSISATC-111
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Revision: November 2009 2006 QX56
Rear Blower Motor
Check that there are no foreign particles inside the intake unit.
Apply 12 volts to terminal 2 and ground to terminal 1 and ensure that
the blower motor rotates freely and quietly.
Rear Blower Motor Resistor
Check continuity between terminals. There will be resistance, but
there should not be an open or short between any two terminals.
WJIA1508E
WJIA1269E

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Revision: November 2009 2006 QX56
SYSTEM DESCRIPTION
Component Parts
Rear air control system components are:

Front air control

Rear air control

Air mix door motor (rear)

Rear blower motor relay

Rear blower motor resistor

Rear blower motor
System Operation
Rear Air Control
When the rear blower switch (front) (integral to the front air control) is in the REAR position the rear blower
motor speeds and the rear temperature and mode are controlled by the rear blower switch (rear) and the rear
temperature switch (rear) (both integral to the rear air control).
DIAGNOSTIC PROCEDURE FOR REAR AIR CONTROL
SYMPTOM:

Blower motor operation is malfunctioning. Refer to ATC-101, "Rear Blower Motor Circuit" .

Temperature and mode operation is malfunctioning.
1. CHECK OPERATION FROM FRONT AIR CONTROL
Does rear temperature and mode operate normally from front air control?
YES or NO
YES >> GO TO 2.
NO >> Refer to AT C - 7 9 , "
DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR (REAR)" .
WJIA1132E

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Revision: November 2009 2006 QX56
9. CHECK BCM INPUT (FAN ON) SIGNAL
Check FAN ON/OFF signal. Refer to AT C - 3 4 , "
CONSULT-II Function
(HVAC)" .
OK or NG
OK >> GO TO 12.
NG >> GO TO 10.
10. CHECK CIRCUIT CONTINUITY BETWEEN BCM AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect BCM connector and front air control connector.
3. Check continuity between BCM harness connector M18 terminal 28 and front air control harness connector M49 terminal 10.
OK or NG
OK >> GO TO 11.
NG >> Repair harness or connector.
11 . CHECK VOLTAGE FOR FRONT AIR CONTROL (FAN ON SIGNAL)
1. Reconnect BCM connector and front air control connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M49 terminal 10 and ground.
OK or NG
OK >> GO TO 12.
NG-1 >> If the voltage is approx. 5V when blower motor is ON, replace front air control. Refer to ATC-144,
"FRONT AIR CONTROL" .
NG-2 >> If the voltage is approx. 0V when blower motor is OFF, replace BCM. Refer to BCS-20, "
BCM" .
FRONT BLOWER CONTROL
DIAL ON
: FAN ON SIG ON
FRONT BLOWER CONTROL
DIAL OFF : FAN ON SIG OFF
WJIA0469E
28 - 10
Continuity should exist.
WJIA0450E
Terminals
Condition Voltage
(+)
(-)
Front air con-
trol connector Terminal No.
M49 10GroundA/C switch: ON
Blower motor
operates
Approx. 0V
A/C switch: OFF Approx. 5V
WJIA0451E

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Revision: November 2009 2006 QX56
*1ATC-176, "Removal and Installation
for Compressor Clutch"
*2ATC-93, "Front Blower Motor Circuit"*3 EM-13, "Checking Drive Belts"
WJIA1371E

ATC-126
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
High-pressure Side is Too Low and Low-pressure Side is Too High
Both High- and Low-pressure Sides are Too Low
Gauge indicationRefrigerant cycleProbable causeCorrective action
High-pressure side is too low and
low-pressure side is too high. High- and low-pressure sides
become equal soon after com-
pressor operation stops.Compressor pressure opera-
tion is improper.
↓
Damaged inside compressor
packings.
Replace compressor.
No temperature difference
between high- and low-pres-
sure sides. Compressor pressure opera-
tion is improper.
↓
Damaged inside compressor
packings.
Replace compressor.
AC356A
Gauge indication
Refrigerant cycleProbable causeCorrective action
Both high- and low-pressure sides
are too low.

There is a big temperature
difference between liquid
tank outlet and inlet. Outlet
temperature is extremely
low.

Liquid tank inlet and expan-
sion valve are frosted. Liquid tank inside is slightly
clogged.

Replace liquid tank.

Check oil for contamination.

Temperature of expansion
valve inlet is extremely low
as compared with areas
near liquid tank.

Expansion valve inlet may
be frosted.

Temperature difference
occurs somewhere in high-
pressure side.High-pressure pipe located
between liquit tank and expan-
sion valve is clogged.

Check and repair malfunc-
tioning parts.

Check oil for contamination.
Expansion valve and liquid
tank are warm or only cool
when touched. Low refrigerant charge.
↓
Leaking fittings or compo-
nents.Check refrigerant system for
leaks. Refer to AT C - 1 8 7 ,
"Checking for Refrigerant
Leaks" .
There is a big temperature dif-
ference between expansion
valve inlet and outlet while the
valve itself is frosted. Expansion valve closes a little
compared with the specifica-
tion.
↓
1. Improper expansion valve
adjustment.
2. Malfunctioning expansion valve.
3. Outlet and inlet may be clogged.

Remove foreign particles by
using compressed air.

Check oil for contamination.
An area of the low-pressure
pipe is colder than areas near
the evaporator outlet. Low-pressure pipe is clogged
or crushed.

Check and repair malfunc-
tioning parts.

Check oil for contamination.
Air flow volume is too low. Evaporator is frozen.

Check intake sensor circuit.
Refer to ATC-142, "
Intake
Sensor Circuit" .

Repair evaporator fins.

Replace evaporator.

Refer to AT C - 9 3 , "Front
Blower Motor Circuit" .
AC353A

ATC-128
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
Insufficient HeatingEJS003XX
SYMPTOM: Insufficient heating
INSPECTION FLOW
*1ATC-58, "Operational Check (Front)"
or AT C - 6 0 , "
Operational Check
(Rear)"
*2 AT C - 7 0 , "Air Mix Door Motor Circuit"*3ATC-56, "A/C System Self-diagno-
sis Function"
*4 ATC-57, "SELF-DIAGNOSIS CODE
CHART"
*5AT C - 9 3 , "Front Blower Motor Circuit"*6EC-192, "DTC P0117, P0118 ECT
SENSOR"
*7 EM-13, "Checking Drive Belts"*8ATC-132, "Water Valve Circuit"
WJIA1889E

BLOWER MOTORATC-149
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Revision: November 2009 2006 QX56
BLOWER MOTORPFP:27226
ComponentsEJS003YB
Front Blower Motor
Rear Blower Motor
Removal and InstallationEJS003YC
FRONT BLOWER MOTOR
Removal
1. Remove the glove box assembly. Refer to IP-14, "Lower Instrument Panel RH and Glove Box" .
2. Disconnect the front blower motor electrical connector.
3. Remove the three screws and remove the front blower motor.
Installation
Installation is in the reverse order of removal.
LJIA0136E
1. Front heater and cooling unit assembly 2. Front blower motor 3. Variable blower control
LJIA0055E
1. Rear blower motor2. Rear blower motor case 3. Rear blower motor resistor