2011 INFINITI QX56 engine

INSUFFICIENT HEATINGHAC-141
< SYMPTOM DIAGNOSIS > [AUTOMATIC AIR CONDITIONING]
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REAR AIR CONDITIONER : DescriptionINFOID:0000000006275992
Symptom
 Insufficient heating
 No warm air comes out. (Air flow volume is normal.)
REAR AIR CONDITIONER : Diagnosis ProcedureINFOID:0000000006275993
CAUTION:
Perform the self-diagnoses with on board diagnosi s and CONSULT-III before performing symptom
diagnosis. If any malfunction result or DTC is detected, perform the corresponding diagnosis.
1.CHECK COOLING SYSTEM
1. Check engine coolant level and check leakage. Refer to CO-8, "
Inspection".
2. Check reservoir tank cap. Refer to CO-11, "
RESERVOIR TANK CAP : Inspection".
3. Check water flow sounds of the engine coolant. Refer to CO-9, "
Refilling".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Refill the engine coolant and repair or replace the parts depending on the inspection results.
2.CHECK HEATER HOSE
Check installation of heater hose by visually or touching.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace parts depending on the inspection results.
3.CHECK REAR HEATER CORE
1. Check temperature of inlet hose and outlet hose of rear heater core.
2. Check that the inlet side of rear heater core is hot and the outlet side is slightly lower than/almost equal to
the inlet side.
CAUTION:
Always perform the temperature inspection in a sh ort period of time because the engine coolant
temperature is very hot.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Replace rear heater core. Refer to HA-48, "
HEATER CORE : Removal and Installation".
4.CHECK AIR LEAKAGE FROM EACH DUCT
Check duct and nozzle, etc. of the rear air conditioning system for air leakage.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace parts depending on the inspection results.
5.CHECK SETTING OF TEMPERATURE SETTING TRIMMER (REAR)
1. Check setting value of temperature setting trimmer (rear). Refer to HAC-69, "
REAR AUTOMATIC AIR
CONDITIONING SYSTEM : Temperature Setting Trimmer (Rear)".
2. Check that the temperature setting trimmer is set to “ − direction”.
NOTE:
The control temperature can be set by the temperature setting trimmer (rear).
3. Set the difference between the set temperature (rear) and control temperature to “0”.
Are the symptoms solved?
YES >> INSPECTION END
NO >> Replace A/C auto amp.. Refer to HAC-146, "
Removal and Installation".
Revision: 2010 May2011 QX56

HAC-142
< SYMPTOM DIAGNOSIS >[AUTOMATIC AIR CONDITIONING]
COMPRESSOR DOSE DOT OPERATE
COMPRESSOR DOSE DOT OPERATE
DescriptionINFOID:0000000006275994
Symptom: Compressor dose not operate.
Diagnosis ProcedureINFOID:0000000006275995
NOTE:
 Perform self-diagnoses with CONSULT-III before perfo
rming symptom diagnosis. If DTC is detected, per-
form the corresponding diagnosis.
 Check that refrigerant is enclosed in cooler cycle normally. If refrigerant amount is shortage from proper
amount, perform inspection of refrigerant leakage.
1.CHECK MAGNET CLUTCH OPERATION
Check magnet clutch. Refer to HAC-126, "
Component Function Check".
Does it operate normally?
YES >> GO TO 2.
NO >> Repair or replace malfunctioning parts.
2.CHECK REFRIGERANT PRESSURE SENSOR
Check refrigerant pressure sensor. Refer to EC-520, "
Component Function Check".
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace malfunctioning parts.
3.CHECK A/C AUTO AMP. OUTPUT SIGNAL
With CONSULT-III
Check “COMP REQ SIG” and “FAN REQ SIG” in “DAT A MONITOR” mode of “HVAC” using CONSULT-III.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Replace A/C auto amp.. Refer to HAC-146, "
Removal and Installation".
4.CHECK ECM INPUT SIGNAL
With CONSULT-III
Check “AIR COND SIG” and “HEATER FAN SW” in “D ATA MONITOR” mode of “ECM” using CONSULT-III.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Check CAN communication system. Refer to LAN-18, "
Trouble Diagnosis Flow Chart".
5.CHECK IPDM E/R INPUT SIGNAL
With CONSULT-III
1. Start engine.
Monitor item Condition Status
COMP REQ SIG A/C switch ON On
OFF Off
FAN REQ SIG Front blower motor ON On
OFF Off
Monitor item Condition Status
COMP REQ SIG A/C switch ON On
OFF Off
HEATER FAN SW Front blower motor ON On
OFF Off
Revision: 2010 May2011 QX56

HRN-2
< PRECAUTION >
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006220273
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severi ty of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” of this
Service Manual.
WARNING:
• To avoid rendering the SRS inopera tive, which could increase the risk of personal injury or death in
the event of a collision that would result in air bag inflation, all maintenance must be performed by
an authorized NISS AN/INFINITI dealer.
 Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the “SRS AIR BAG”.
 Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
 When working near the Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the ignition ON or engine running, DO NOT use air or electric power tools or strike near the sensor(s)
with a hammer. Heavy vibration could activate the sensor(s) and deploy the air bag(s), possibly
causing serious injury.
 When using air or electric power tools or hammers , always switch the ignition OFF, disconnect the
battery, and wait at least 3 minu tes before performing any service.
Revision: 2010 May2011 QX56

PRECAUTIONSINL-3
< PRECAUTION >
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PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006377028
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severi ty of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” of this
Service Manual.
WARNING:
• To avoid rendering the SRS inoper ative, which could increase the risk of personal injury or death in
the event of a collision that would result in air ba g inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.
 Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintentional act ivation of the system. For removal of Spiral Cable and Air Bag
Module, see the “SRS AIR BAG”.
 Do not use electrical test equipm ent on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
 When working near the Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the
ignition ON or engine running, DO NOT use air or electric power tools or strike near the sensor(s)
with a hammer. Heavy vibration could activate the sensor(s) and deploy the air bag(s), possibly
causing serious injury.
 When using air or electric power tools or hammers , always switch the ignition OFF, disconnect the
battery, and wait at least 3 minutes before performing any service.
Revision: 2010 May2011 QX56

INL-12
< SYSTEM DESCRIPTION >
DIAGNOSIS SYSTEM (BCM)
DIAGNOSIS SYSTEM (BCM)
COMMON ITEM
COMMON ITEM : CONSULT-III Function (BCM - COMMON ITEM)INFOID:0000000006368143
APPLICATION ITEM
CONSULT-III performs the following functions via CAN communication with BCM.
SYSTEM APPLICATION
BCM can perform the following functions for each system.
NOTE:
It can perform the diagnosis modes except the following for all sub system selection items.
×: Applicable item
*: This item is indicated, but not used.
FREEZE FRAME DATA (FFD)
The BCM records the following vehicle condition at the time a particular DTC is detected, and displays on
CONSULT-III.
Diagnosis mode Function Description
Work Support Changes the setting for each system function.
Self Diagnostic Result Displays the diagnosis results judged by BCM. Refer to BCS-57, "
DTCIndex".
CAN Diag Support Monitor Monitors the reception status of CAN communication viewed from BCM. Refer to CONSULT-III opera-
tion manual.
Data Monitor The BCM input/output signals are displayed.
Active Test The signals used to activate ea ch device are forcibly supplied from BCM.
Ecu Identification The BCM part number is displayed.
Configuration  Read and save the vehicle specification.
 Write the vehicle specification when replacing BCM.
System Sub system selection item Diagnosis mode
Work Support Data Monitor Active Test
Door lock DOOR LOCK ×××
Rear window defogger REAR DEFOGGER ××
Warning chime BUZZER ××
Interior room lamp timer INT LAMP ×××
Exterior lamp HEAD LAMP ×××
Wiper and washer WIPER ×××
Turn signal and hazard warning lamps FLASHER ×××
— AIR CONDITONER* ××
 Intelligent Key system
 Engine start system INTELLIGENT KEY
×××
Combination switch COMB SW ×
Body control system BCM ×
IVIS IMMU ×××
Interior room lamp battery saver BATTERY SAVER ×××
Back door TRUNK ×
Vehicle security system THEFT ALM ×××
RAP system RETAINED PWR ×
Signal buffer system SIGNAL BUFFER ××
Revision: 2010 May2011 QX56

DIAGNOSIS SYSTEM (BCM)INL-13
< SYSTEM DESCRIPTION >
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INT LAMP
CONSULT screen item Indication/Unit Description
Vehicle Speed km/h Vehicle speed of the moment a particular DTC is detected
Odo/Trip Meter km Total mileage (Odometer value) of the moment a particular DTC is detected
Vehicle Condition SLEEP>LOCK
Power position status of
the moment a particular
DTC is detected While turning BCM status from low power consumption mode to
normal mode (Power supply position is “LOCK”)
SLEEP>OFF While turning BCM status from low power consumption mode to
normal mode (Power supply position is “OFF”.)
LOCK>ACC While turning power supply position from “LOCK” to “ACC”
ACC>ON While turning power supply position from “ACC” to “IGN”
RUN>ACC While turning power supply position
from “RUN” to “ACC” (Vehicle
is stopping and selector lever is except P position.)
CRANK>RUN While turning power su
pply position from “CRANKING” to “RUN”
(From cranking up the engine to run it)
RUN>URGENT While turning power su
pply position from “RUN“ to “ACC” (Emer-
gency stop operation)
ACC>OFF While turning power supply position from “ACC” to “OFF”
OFF>LOCK While turning power supply position from “OFF” to “LOCK”
OFF>ACC While turning power supply position from “OFF” to “ACC”
ON>CRANK While turning po wer supply position from “IGN” to “CRANKING”
OFF>SLEEP While turning BCM status from normal mode (Power supply posi-
tion is “OFF”.) to low power consumption mode
LOCK>SLEEP While turning BCM status from normal mode (Power supply posi-
tion is “LOCK”.) to low power consumption mode
LOCK Power supply position is “LOCK” (Ignition switch OFF with steer-
ing is locked.)
OFF Power supply position
is “OFF” (Ignition switch OFF with steering
is unlocked.)
ACC Power supply position is “ACC” (Ignition switch ACC)
ON Power supply position is “IGN” (Ignition switch ON with engine
stopped)
ENGINE RUN Power supply posi
tion is “RUN” (Ignition switch ON with engine
running)
CRANKING Power supply position is “CRANKING” (At engine cranking)
IGN Counter 0 - 39 The number of times that ignition switch is turned ON after DTC is detected
 The number is 0 when a malfunction is detected now.
 The number increases like 1
→ 2 → 3...38 → 39 after returning to the normal condition
whenever ignition switch OFF → ON.
 The number is fixed to 39 until the self-diagnosis results are erased if it is over 39.
Revision: 2010 May2011 QX56

PUSH-BUTTON IGNITION SWITCH ILLUMINATION CIRCUIT
INL-65
< DTC/CIRCUIT DIAGNOSIS >
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PUSH-BUTTON IGNITION SWIT CH ILLUMINATION CIRCUIT
Component Function CheckINFOID:0000000006265016
1.CHECK PUSH-BUTTON IGNITION SWITCH ILLUMINATION OPERATION
CONSULT-III ACTIVE TEST
1. Turn the ignition switch ON.
2. Select “ENGINE SW ILLUMI” of BCM (I NTELLIGENT KEY) active test item.
3. With operating the test items, check that the pus h-button ignition switch illumination turns ON/OFF.
Does the push-button ignition switch illumination turn ON/OFF?
YES >> Push-button ignition switch illumination circuit is normal.
NO >> Refer to INL-65, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006265017
1.CHECK PUSH-BUTTON IGNITION SWITCH ILLUMINATION POWER SUPPLY OUTPUT
1. Turn ignition switch OFF.
2. Lighting switch OFF.
3. Disconnect push-button ignition switch connector.
4. Check voltage between push-button ignition switch harness connector and ground.
Is the inspection result normal?
YES >> GO TO 4.
NO >> GO TO 2.
2.CHECK PUSH-BUTTON IGNITION SWITCH ILLU MINATION POWER SUPPLY OPEN CIRCUIT
1. Turn the ignition switch OFF.
2. Disconnect BCM connector.
3. Check continuity between BCM harness connector and the push-button ignition switch harness connector.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace harnesses.
3.CHECK PUSH-BUTTON IGNITION SWITCH ILLU MINATION POWER SUPPLY SHORT CIRCUIT
Check continuity between BCM harness connector and ground.
Is the inspection result normal?
YES >> Replace BCM. Refer to BCS-81, "Removal and Installation".
On : Push-button ignition
switch illumination ON
Off : Push-button ignition switch illumination OFF
(+)
(–) Condition Vo l ta g e
(Approx.)
Push-button ignition switch
Connector Terminal
M101 3 Ground Push-button ignition
switch illuminationON Condition 12 V
OFF Condition 0 V
BCM Push-button ignition switch Continuity
Connector Terminal Connector Terminal
M71 90 M101 3 Existed
BCM GroundContinuity
Connector Terminal
M71 90 Not existed
Revision: 2010 May2011 QX56

PRECAUTIONSINT-3
< PRECAUTION >
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PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006415653
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severi ty of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” of this
Service Manual.
WARNING:
• To avoid rendering the SRS inoper ative, which could increase the risk of personal injury or death in
the event of a collision that would result in air ba g inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.
 Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintentional act ivation of the system. For removal of Spiral Cable and Air Bag
Module, see the “SRS AIR BAG”.
 Do not use electrical test equipm ent on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
 When working near the Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the
ignition ON or engine running, DO NOT use air or electric power tools or strike near the sensor(s)
with a hammer. Heavy vibration could activate the sensor(s) and deploy the air bag(s), possibly
causing serious injury.
 When using air or electric power tools or hammers , always switch the ignition OFF, disconnect the
battery, and wait at least 3 minutes before performing any service.
Precaution Necessary for Steering Wh eel Rotation after Battery Disconnect
INFOID:0000000006415652
NOTE:
 Before removing and installing any control units, first tu rn the push-button ignition switch to the LOCK posi-
tion, then disconnect both battery cables.
 After finishing work, confirm that all control unit connectors are connected properly, then re-connect both
battery cables.
 Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If a DTC is detected, perform trouble diagnos is according to self-diagnosis results.
For vehicle with steering lock unit, if the battery is disconnected or discharged, the steering wheel will lock and
cannot be turned.
If turning the steering wheel is required with the batte ry disconnected or discharged, follow the operation pro-
cedure below before starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Turn the push-button ignition switch to ACC position. (At this time, the steering lock will be released.)
3. Disconnect both battery cables. The steering lock wil l remain released with both battery cables discon-
nected and the steering wheel can be turned.
4. Perform the necessary repair operation.
Revision: 2010 May2011 QX56