wiring INFINITI QX56 2011 Factory Service Manual

GI-42
< BASIC INSPECTION >
SERVICE INFORMATION FOR ELECTRICAL INCIDENT
An unclamped or loose harness can cause wiring to be pinched by seat components (such as slide guides)
during vehicle vibration. If the wiring runs under s eating areas, inspect wire routing for possible damage or
pinching.
HEAT SENSITIVE
 The customer's concern may occur during hot weather or after car has sat for a short time. In such cases you will want to check for a
heat sensitive condition.
 To determine if an electrical component is heat sensitive, heat the component with a heat gun or equivalent.
CAUTION:
Never heat components above 60 °C (140 °F).
 If incident occurs while heating the unit, either replace or properly insulate the component.
FREEZING
 The customer may indicate the incident goes away after the carwarms up (winter time). The cause could be related to water freez-
ing somewhere in the wiring/electrical system.
 There are two methods to check for this. The first is to arrange for the owner to leave his car overnight. Check it will get cold enough
to demonstrate his complaint. Leave the car parked outside over-
night. In the morning, do a quick and thorough diagnosis of those
electrical components which could be affected.
 The second method is to put the suspect component into a freezer long enough for any water to freeze. Reinstall the part into the car
and check for the reoccurrence of the incident. If it occurs, repair or
replace the component.
WATER INTRUSION
The incident may occur only during high humidity or in rainy/snowy
weather. In such cases the incident could be caused by water intru-
sion on an electrical part. This can be simulated by soaking the car
or running it through a car wash.
CAUTION:
Never spray water directly on any electrical components.
ELECTRICAL LOAD
The incident may be electrical load sensitive. Perform diagnosis with
all accessories (including A/C, rear window defogger, radio, fog
lamps) turned on.
COLD OR HOT START UP
On some occasions an electrical incident may occur only when the car is started cold, or it may occur when
the car is restarted hot shortly after being turned off. In these cases you may have to keep the car overnight to
make a proper diagnosis.
JPAIA0733GB
SGI843
SGI844
SGI845
Revision: 2010 May2011 QX56

SERVICE INFORMATION FOR ELECTRICAL INCIDENTGI-43
< BASIC INSPECTION >
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Circuit InspectionINFOID:0000000006280855
DESCRIPTION
 In general, testing electrical circuits is an easy task if it is approached in a logical and organized method. Before beginning it is important to have all available information on the system to be tested. Also, get a thor-
ough understanding of system operation. Then you will be able to use the appropriate equipment and follow
the correct test procedure.
 You may have to simulate vehicle vibrations while te sting electrical components. Gently shake the wiring
harness or electrical component to do this.
NOTE:
Refer to GI-37, "
How to Check Terminal" to probe or check terminal.
TESTING FOR “OPENS” IN THE CIRCUIT
Before you begin to diagnose and test the system, you should rough sketch a schematic of the system. This
will help you to logically walk through the diagnosis process. Drawing the sketch will also reinforce your work-
ing knowledge of the system.
Continuity Check Method
The continuity check is used to find an open in the circui t. The digital multimeter (DMM) set on the resistance
function will indicate an open circuit as over limit (no beep tone or no ohms symbol). Check to always start with
the DMM at the highest resistance level.
To help in understanding the diagnosis of open circui ts, please refer to the previous schematic.
 Disconnect the battery negative cable.
 Start at one end of the circuit and work your way to the other end. (At the fuse block in this example)
 Connect one probe of the DMM to the fuse block terminal on the load side.
 Connect the other probe to the fuse block (power) side of SW1. Little or no resistance will indicate that por-
tion of the circuit has good continuity. If there were an open in the circuit, the DMM would indicate an over
limit or infinite resistance condition. (point A)
 Connect the probes between SW1 and the relay. Little or no resistance will indicate that portion of the circuit
has good continuity. If there were an open in the circuit, t he DMM would indicate an over limit or infinite resis-
tance condition. (point B)
 Connect the probes between the relay and the solenoid. Little or no resistance will indicate that portion of the
circuit has good continuity. If there were an open in the ci rcuit, the DMM would indicate an over limit or infi-
nite resistance condition. (point C)
Any circuit can be diagnosed using the approach in the previous example.
Voltage Check Method
To help in understanding the diagnosis of open circui ts please refer to the previous schematic.
In any powered circuit, an open can be found by methodica lly checking the system for the presence of voltage.
This is done by switching the DMM to the voltage function.
 Connect one probe of the DMM to a known good ground.
 Begin probing at one end of the circuit and work your way to the other end.
 With SW1 open, probe at SW1 to check for voltage. voltage: open is further down the circuit than SW1.
OPEN A circuit is open when there is no continuity through a section of the circuit.
SHORT There are two types of shorts.
 SHORT CIRCUIT
When a circuit contacts another circuit and causes the normal resistance to
change.
 SHORT TO GROUND When a circuit contacts a ground source and grounds the circuit.
SGI846-A
Revision: 2010 May2011 QX56

SERVICE INFORMATION FOR ELECTRICAL INCIDENTGI-45
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 When inspecting a ground connection follow these rules:
- Remove the ground bolt or screw.
- Inspect all mating surfaces for tarnish, dirt, rust, etc.
- Clean as required to assure good contact.
- Reinstall bolt or screw securely.
- Inspect for “add-on” accessories which may be interfering with the ground circuit.
- If several wires are crimped into one ground eyelet terminal, check for proper crimps. Check all of the wires are clean, securely fastened and providing a good ground path. If multiple wires are cased in one eyelet
check no ground wires have excess wire insulation.
 For detailed ground distribution information, re fer to “Ground Distribution” in PG section.
VOLTAGE DROP TESTS
 Voltage drop tests are often used to find components or circuits which have excessive resistance. A voltage
drop in a circuit is caused by a resistance when the circuit is in operation.
 Check the wire in the illustration. When measuring re sistance with DMM, contact by a single strand of wire
will give reading of 0 ohms. This would indicate a good circuit. When the circuit operates, this single strand
of wire is not able to carry the current. The single st rand will have a high resistance to the current. This will
be picked up as a slight voltage drop.
 Unwanted resistance can be caused by many situations as follows:
- Undersized wiring (single strand example)
- Corrosion on switch contacts
- Loose wire connections or splices.
 If repairs are needed always use wire that is of the same or larger gauge.
Measuring Voltage Drop — Accumulated Method
 Connect the DMM across the connector or part of the ci rcuit you want to check. The positive lead of the
DMM should be closer to power and the negative lead closer to ground.
 Operate the circuit.
 The DMM will indicate how many volts are being used to “push” current through that part of the circuit.
SGI853
Revision: 2010 May2011 QX56

GI-50
< BASIC INSPECTION >
CONSULT-III/GST CHECKING SYSTEM
CONSULT-III/GST Data Link Connector (DLC) Circuit
INFOID:0000000006280858
INSPECTION PROCEDURE
If the CONSULT-III/GST cannot diagnose the system properly, check the following items.
NOTE:
The DDL1 and DDL2 circuits from DLC pins 12, 13, 14 and 15 may be connected to more than one system. A
short in a DDL circuit connected to a control unit in one system may affect CONSULT-III access to other sys-
tems.
If the GST cannot operate properly, check the circ uit based on the information of SAE J1962 and ISO 15031-
3.
Symptom Check item
CONSULT-III/GST cannot ac-
cess any system.  CONSULT-III/GST DLC power supply circuit (Terminal 8 and 16) and ground circuit (Terminal 4 and
5)
CONSULT-III cannot access in-
dividual system. (Other sys-
tems can be accessed.)  Power supply and ground circuit for the control unit of the system (For detailed circuit, refer to wiring
diagram for each system.)
 Open or short circuit between the system and CONSULT-III DLC (For detailed circuit, refer to wiring
diagram for each system.)
 Open or short circuit CAN communication line. Refer to LAN-18, "
Trouble Diagnosis Flow Chart".
Revision: 2010 May2011 QX56

CONSULT-III/GST CHECKING SYSTEMGI-51
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Wiring Diagram - CONSULT- III/GST CHECKING SYSTEM -INFOID:0000000006280859
WITH ICC
JCAWM0358GB
Revision: 2010 May2011 QX56

GW-2
< PRECAUTION >
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006257243
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.
Precaution Necessary for Steering W heel Rotation after Battery Disconnect
INFOID:0000000006257244
NOTE:
 Before removing and installing any control units, first tu rn the push-button ignition switch to the LOCK posi-
tion, then disconnect bot h 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 bat tery 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 wi ll 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

SQUEAK AND RATTLE TROUBLE DIAGNOSESGW-7
< SYMPTOM DIAGNOSIS >
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68370-4B000: 15 ×25 mm (0.59 ×0.98 in) pad/68239-13E00: 5 mm (0.20 in) wide tape roll
The following materials, not found in the kit, can also be used to repair squeaks and rattles.
UHMW (TEFLON) TAPE
Insulates where slight movement is present. Ideal for instrument panel applications.
SILICONE GREASE
Used in place of UHMW tape that will be visible or not fit. Will only last a few months.
SILICONE SPRAY
Use when grease cannot be applied.
DUCT TAPE
Use to eliminate movement.
CONFIRM THE REPAIR
Confirm that the cause of a noise is repaired by test driving the vehicle. Operate the vehicle under the same
conditions as when the noise originally occurred. Refer to the notes on the Diagnostic Worksheet.
Inspection ProcedureINFOID:0000000006108036
Refer to Table of Contents for specific component removal and installationinformation.
INSTRUMENT PANEL
Most incidents are caused by contact and movement between:
1. The cluster lid A and instrument panel
2. Acrylic lens and combination meter housing
3. Instrument panel to front pillar garnish
4. Instrument panel to windshield
5. Instrument panel mounting pins
6. Wiring harnesses behind the combination meter
7. A/C defroster duct and duct joint
These incidents can usually be located by tapping or moving the components to duplicate the noise or by
pressing on the components while driving to stop the noise. Most of these incidents can be repaired by
applying felt cloth tape or silicon spray (in hard to reach areas). Urethane pads can be used to insulate
wiring harness.
CAUTION:
Do not use silicone spray to isolate a squeak or rattle. If you saturatethe area with silicone, you
will not be able to recheck the repair.
CENTER CONSOLE
Components to pay attention to include:
1. Shifter assembly cover to finisher
2. A/C control unit and cluster lid C
3. Wiring harnesses behind audio and A/C control unit
The instrument panel repair and isolation procedures also apply to thecenter console.
DOORS
Pay attention to the:
1. Finisher and inner panel making a slapping noise
2. Inside handle escutcheon to door finisher
3. Wiring harnesses tapping
4. Door striker out of alignment causing a popping noise on startsand stops
Tapping or moving the components or pressing on them while driving to duplicate the conditions can isolate
many of these incidents. You can usually insulate the ar eas with felt cloth tape or insulator foam blocks from
the Nissan Squeak and Rattle Kit (J-43980) to repair the noise.
TRUNK
Trunk noises are often caused by a loose jack or loose items put intothe trunk by the owner.
In addition look for:
1. Trunk lid dumpers out of adjustment
2. Trunk lid striker out of adjustment
Revision: 2010 May2011 QX56

PRECAUTIONSHA-3
< PRECAUTION >
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PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006276136
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:0000000006276137
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

HAC-2
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) : Automatic Intake Control (Exhaust Gas /
Outside Odor Detecting Mechanism) .....................
28
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) : Plasmacluster Control .................................
29
OPERATION ......................................................30
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM ........................................................................ ...
30
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : Switch Name and Function ....................... ...
30
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM ........................................................................ ...
35
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM : Switch Name and Function ....................... ...
35
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) ....................................................................... ...
37
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) : Switch Name and Function .........................
37
DIAGNOSIS SYSTEM (HVAC) ..........................39
Description ........................................................... ...39
CONSULT-III Function ...........................................39
ECU DIAGNOSIS INFORMATION ..............42
A/C AUTO AMP. ............................................. ...42
Reference Value .................................................. ...42
Fail-safe ..................................................................45
DTC Index ..............................................................45
ECM, IPDM E/R .................................................47
List of ECU Reference ......................................... ...47
WIRING DIAGRAM .....................................48
AUTOMATIC AIR CONDITIONING SYSTEM ...48
Wiring Diagram .................................................... ...48
BASIC INSPECTION ...................................60
DIAGNOSIS AND REPAIR WORK FLOW ..... ...60
Work Flow ............................................................ ...60
OPERATION INSPECTION ............................ ...62
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM ........................................................................ ...
62
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : Work Procedure ........................................ ...
62
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM ........................................................................ ...
64
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM : Work Procedure ........................................ ...
64
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) ....................................................................... ...
66
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) : Work Procedure ..........................................
66
SYSTEM SETTING ............................................68
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM ........................................................................ ...
68
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : Temperature Setting Trimmer (Front) ..........
68
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : Foot Position Setting Trimmer ......................
68
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : Inlet Port Memory Function (FRE) ................
69
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : Inlet Port Memory Function (REC) ...............
69
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM ........................................................................ ...
69
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM : Temperature Setting Trimmer (Rear) ...........
69
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) ....................................................................... ...
70
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) : Exhaust Gas / Outside Odor Detecting
Sensor Sensitivity Adjustment Function ..................
70
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) : Auto Intake Switch Interlocking Movement
Change Function .....................................................
70
DTC/CIRCUIT DIAGNOSIS ........................72
U1000 CAN COMM CIRCUIT ......................... ...72
Description ........................................................... ...72
DTC Logic ...............................................................72
Diagnosis Procedure ...............................................72
U1010 CONTROL UNIT (CAN) .........................73
Description ........................................................... ...73
DTC Logic ...............................................................73
Diagnosis Procedure ...............................................73
B2578, B2579 FRONT IN-VEHICLE SENSOR ...74
DTC Logic ............................................................ ...74
Diagnosis Procedure ...............................................74
Component Inspection ............................................75
B257B, B257C AMBIENT SENSOR .................77
DTC Logic ............................................................ ...77
Diagnosis Procedure ...............................................77
Component Inspection ............................................78
B2581, B2582 INTAKE SENSOR .....................80
DTC Logic ............................................................ ...80
Diagnosis Procedure ...............................................80
Component Inspection ............................................81
B262A, B262B, B2657, B2658 EXHAUST
GAS/OUTSIDE ODOR DETECTING SENSOR
...
83
DTC Logic ............................................................ ...83
Diagnosis Procedure ...............................................83
Revision: 2010 May2011 QX56

PRECAUTIONSHAC-5
< PRECAUTION > [AUTOMATIC AIR CONDITIONING]
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PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006275847
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