2008 INFINITI QX56 ignition

INTAKE DOOR MOTORHAC-43
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector M49 terminal 21 and terminal 22.
Is the inspection result normal?
OK >> Replace intake door motor. Refer to VTL-22, "Removal
and Installation".
NO >> GO TO 5.
5.CHECK INTAKE DOOR MOTOR CIRCUITS FOR OPEN
1. Disconnect the intake door motor harness connector.
2. Check continuity between A/C auto amp. harness connector M49 (A) terminal 21, 22 and the intake door motor harness con-
nector M58 (B) terminal 1, 6.
Is the inspection result normal?
YES >> Replace intake door motor. Refer to VTL-22, "Removal
and Installation" .
NO >> Repair or replace harness as necessary. Continuity should exist.
AWIIA0149ZZ
21 - 6
: Continuity should exist.
22 - 1 : Continuity should exist.
AWIIA0234ZZ
Revision: March 2010 2008 QX56

DEFROSTER DOOR MOTOR CIRCUITHAC-45
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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Defroster Door Motor Co mponent Function CheckINFOID:0000000001679793
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING O PERATIONAL CHECK - DEFROSTER DOOR
1. Press the mode switch and select vent ( ).
2. Press the defrost switch ( ). Defroster indicator should illuminate (on display).
3. Listen for defroster door position change (blower sound should change slightly).
Can the symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK FOR ANY SYMPTOMS
Perform a complete operational check for any symptoms. Refer to HAC-4, "
Operational Check (Front)".
Does another symptom exist?
YES >> Refer to HAC-3, "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 DEFROSTER DOOR MOTOR
Perform diagnostic procedure for defroster door motor. Refer to HAC-45, "
Defroster Door Motor Component
Function Check".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair PBR circuit or replace defroster door motor. Refer to VTL-21, "
Removal and Installation".
5.CHECK DEFROSTER DOOR OPERATION
Check and verify defroster door mechanism for smooth operation.
Is the inspection result normal?
YES >> Replace defroster door motor. Refer to VTL-21, "Removal and Installation".
NO >> Repair defroster door mechanism.
Defroster Door Motor Diagnosis ProcedureINFOID:0000000001679794
SYMPTOM:
• Defroster door does not change.
• Defroster door motor does not operate normally.
DIAGNOSTIC PROCEDURE FOR DEFROSTER DOOR MOTOR
1.CHECK A/C AUTO AMP. FOR POWER AND GROUND
1. Turn ignition switch ON.
2. Press the defroster switch ( ).
3. Check voltage between A/C auto amp. harness connector M49 terminal 24 and terminal 23 and press the defroster switch ( )
again.
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
A/C auto amp.: M49 24 23 Press de-
froster switch Battery
voltage
AWIIA0152ZZ
Revision: March 2010 2008 QX56

HAC-46
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
DEFROSTER DOOR MOTOR CIRCUIT
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK DEFROSTER DOOR MOTOR CIRCUITS FOR SHORT TO GROUND
1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector M49 terminal 23, 24 and ground.
Is the inspection result normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and
Installation".
NO >> Repair or replace harness as necessary.
3.CHECK A/C AUTO AMP. FOR GROUND AND POWER
1. Press the defroster switch ( ).
2. Check voltage between A/C auto amp. harness connector M49 terminal 23 and terminal 24 and pr ess the defroster switch ( )
again.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Replace A/C auto amp. Refer to VTL-7, "
Removal and Installation".
4.CHECK DEFROSTER DOOR MOTOR AND CIRCUITS FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector M49 terminal 23 and terminal 24.
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
5.CHECK DEFROSTER DOOR MOTOR CIRCUITS FOR OPEN
1. Disconnect the defroster door motor harness connector.
2. Check continuity between A/C auto amp. harness connector M49 (A) terminal 23, 24 and the defroster door motor harness
connector M144 (B) terminal 1, 6.
Is the inspection result normal?
YES >> Replace defroster door motor. Refer to VTL-21,
"Removal and Installation".
23 - Ground : Continuity should not exist.
24 - Ground : Continuity should not exist.
AWIIA0153ZZ
Connector
Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
A/C auto amp.: M49 23 24 Press de-
froster
switch Battery
voltage
AWIIA0154ZZ
Continuity should exist.
AWIIA0155ZZ
23 - 1 : Continuity should exist.
24 - 6 : Continuity should exist.
AWIIA0156ZZ
Revision: March 2010 2008 QX56

DEFROSTER DOOR MOTOR CIRCUITHAC-47
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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NO >> Repair or replace harness as necessary.
6.CHECK A/C AUTO AMP. FOR PBR POWER AND GROUND
1. Reconnect A/C auto amp. harness connector.
2. Turn ignition switch ON.
3. Check voltage between A/C auto amp. harness connector M50 (A) terminal 28 and M49 (B) terminal 3.
Is the inspection result normal?
YES >> GO TO 8.
NO >> GO TO 7.
7.CHECK PBR REFERENCE VOLTAGE CIRCUIT FOR SHORT TO GROUND
1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector M50 terminal 28 and ground.
Is the inspection result normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and
Installation".
NO >> Repair or replace harness as necessary.
8.CHECK PBR REFERENCE VOLT AGE AND GROUND CIRCUITS
1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector M50 (A) terminal 28 and M49 (B) terminal 3.
Is the inspection result normal?
YES >> GO TO 10.
NO >> GO TO 9.
9.CHECK PBR REFERENCE VOLTAGE CIRCUIT FOR OPEN
1. Disconnect the defroster door motor harness connector.
2. Check continuity between defroster door motor harness connec- tor M144 (B) terminal 3, 2 and A/C auto amp. harness connector
M50 (A) terminal 28, and M49 (C) terminal 3.
Is the inspection result normal?
YES >> Replace defroster door motor. Refer to VTL-21,
"Removal and Installation".
NO >> Repair or replace harness as necessary.
10.CHECK PBR FEEDBACK VOLTAGE
Connector Te r m i n a l s
Voltage (Ap-
prox.)
(+) (-)
A/C auto amp.: M50, M49 28 35V
AWIIA0118ZZ
Continuity should not exist.
AWIIA0119ZZ
Continuity should exist.
AWIIA0120ZZ
28 - 3 : Continuity should exist.
3 - 2 : Continuity should exist.
AWIIA0121ZZ
Revision: March 2010 2008 QX56

HAC-48
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
DEFROSTER DOOR MOTOR CIRCUIT
1. Reconnect the A/C auto
amp. harness connector.
2. Turn ignition switch ON.
3. Check voltage between A/C auto amp. harness connector M49 terminal 10 and ground while cycling defroster switch on and off.
Is the inspection result normal?
YES >> GO TO 12.
NO >> GO TO 11.
11 .CHECK PBR FEEDBACK SIGNAL CIRCUIT FOR SHORT TO GROUND
1. Turn ignition switch OFF.
2. Disconnect A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector M49 terminal 10 and ground.
Is the inspection result normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and
Installation".
NO >> Repair or replace harness as necessary.
12.CHECK PBR FEEDBACK CIRCUIT FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect the defroster door motor harness connector and A/C auto amp. harness connector.
3. Check continuity between defroster door motor harness connec- tor M144 (B) terminal 4 and A/C auto amp. harness connector
M49 (A) terminal 10
Is the inspection result normal?
YES >> Replace defroster door motor. Refer to VTL-21,
"Removal and Installation".
NO >> Repair or replace harness as necessary. Voltage : Approx. 1V - 4.5V
AWIIA0157ZZ
Continuity should not exist.
AWIIA0158ZZ
Continuity should exist.
AWIIA0159ZZ
Revision: March 2010
2008 QX56

HAC-52
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
BLOWER MOTOR CONTROL SYSTEM
Check 20A fuses [No. 24 and 27 (Located in the fuse and fusible link box)]. For fuse layout. Refer to
PG-70,
"Terminal Arrangement".
Is the inspection result normal?
YES >> GO TO 2.
NO >> GO TO 7.
2.CHECK FRONT BLOWER MOTOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front blower motor connector.
3. Turn ignition switch ON.
4. Press the A/C switch.
5. Press the front blower control "+" switch to maximum speed.
6. Check voltage between front blower motor harness connector M62 terminal 2 and ground.
Is the inspection result normal?
YES >> GO TO 10.
NO >> GO TO 3.
3.CHECK FRONT BLOWER MOTOR RELAY (S WITCH SIDE) POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front blower motor relay.
3. Check voltage between front blower motor relay harness con- nector M107 terminal 5 and ground.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair harness or connector.
4.CHECK FRONT BLOWER MOTOR RELAY
Turn ignition switch OFF.
Check front blower motor relay. Refer to HAC-54, "
Front Blower Motor Component Inspection".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Replace front blower motor relay.
5.CHECK FRONT BLOWER MOTOR RELA Y (SWITCH SIDE) CIRCUIT FOR OPEN
Check continuity between front blower motor relay harness connec-
tor M107 terminal 3 and front blower motor harness connector M62
terminal 2.
Is the inspection result normal?
YES >> GO TO 6.
NO >> Repair harness or connector.
6.CHECK FRONT BLOWER MOTOR RE LAY (COIL SIDE) POWER SUPPLY
Fuses are good.
2 - Ground
: Battery voltage
WJIA1331E
5 - Ground: Battery voltage
WJIA1886E
3 - 2 : Continuity should exist.
WJIA1360E
Revision: March 2010 2008 QX56

BLOWER MOTOR CONTROL SYSTEMHAC-53
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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1. Turn ignition switch ON.
2. Check voltage between front blower motor relay harness con- nector M107 terminal 2 and ground.
Is the inspection result normal?
YES >> Repair front blower motor ground circuit or connector.
NO >> Repair harness or connector.
7.REPLACE FUSES
Replace fuses.
Does the fuse blow?
YES >> • If fuse blows without activating the front blower motor, repair short between fuse and front blower motor relay.
• If fuse blows activating the front blower motor, GO TO 8.
NO >> Inspection End.
8.CHECK FRONT BLOWER MOTOR POWER SUPPLY CIRCUIT FOR SHORT
1. Turn ignition switch OFF.
2. Disconnect front blower motor connector, front blower motor relay and variable blower control connector.
3. Check continuity between variable blower control harness con- nector M122 terminal 4 and ground.
Is the inspection result normal?
YES >> GO TO 9.
NO >> Repair harness or connector.
9.CHECK FRONT BLOWER MOTOR
Check front blower motor. Refer to HAC-54, "
Front Blower Motor Component Inspection".
Is the inspection result normal?
YES >> Replace variable blower control (front). Refer to VTL-29, "Removal and Installation".
NO >> Replace front blower motor. Refer to VTL-12, "
Removal and Installation".
10.CHECK FRONT BLOWER MOTOR
Check front blower motor. Refer to HAC-54, "
Front Blower Motor Component Inspection".
Is the inspection result normal?
YES >> GO TO 11.
NO >> Replace front blower motor. Refer to VTL-12, "
Removal and Installation".
11 .CHECK BLOWER MOTOR GROUND CIRCUIT
1. Disconnect variable blower control connector.
2. Check continuity between front blower motor harness connector M62 (B) terminal 1 and variable blower control harness connec-
tor M122 (A) terminal 2.
Is the inspection result normal?
YES >> GO TO 12.
NO >> Repair harness or connector. 2 - Ground : Battery voltage
WJIA1363E
4 - Ground
: Continuity should not exist.
AWIIA0177ZZ
1 - 2 : Continuity should exist.
AWIIA0179ZZ
Revision: March 2010 2008 QX56

HAC-54
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
BLOWER MOTOR CONTROL SYSTEM
12.CHECK VARIABLE BLOWER CONTRO
L POWER SUPPLY CIRCUIT FOR OPEN
1. Disconnect front blower motor relay.
2. Check continuity between front blower motor relay harness con- nector M107 (A) terminals 3 and variable blower control harness
connector M122 (B) terminal 4.
Is the inspection result normal?
YES >> GO TO 13.
NO >> Repair harness or connector.
13.CHECK VARIABLE BLOWER CONTROL GROUND CIRCUIT
Check continuity between variable blower control harness connector
M122 terminal 1 and ground.
Is the inspection result normal?
YES >> GO TO 14.
NO >> Repair harness or connector.
14.CHECK VARIABLE BLOWER CONTROL SIGNAL CIRCUIT
1. Reconnect all disconnected component connectors.
2. Disconnect A/C auto amp. connector.
3. Turn ignition switch ON.
4. Press the blower (+) switch to maximum speed.
5. Check voltage between A/C auto amp. harness connector M49 terminal 13 and ground.
Is the inspection result normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and
Installation".
NO >> GO TO 15.
15.CHECK VARIABLE BLOWER CONT ROL SIGNAL CIRCUIT FOR OPEN
1. Disconnect variable blower control connector.
2. Check continuity between A/C auto amp. harness connector M49 (B) terminal 13 and variable blower control harness con-
nector M122 (A) terminal 3.
Is the inspection result normal?
YES >> Replace variable blower control. Refer to VTL-29,
"Removal and Installation".
NO >> Repair harness or connector.
Front Blower Motor Component InspectionINFOID:0000000001679798
COMPONENT INSPECTION
3 - 4 : Continuity should exist.
AWIIA0175ZZ
1 - Ground: Continuity should exist.
AWIIA0180ZZ
13 - Ground : Approx. 4.5V
AWIIA1129ZZ
13 - 3: Continuity should exist.
AWIIA0178ZZ
Revision: March 2010 2008 QX56