2009 INFINITI QX56 wheel

TM-26
< FUNCTION DIAGNOSIS >
A/T CONTROL SYSTEM
When shifting from the lock-up released state to the lock-up applied state, the current output to the torque con-
verter clutch solenoid is controlled with the TCM. In th is way, when shifting to the lock-up applied state, the
torque converter clutch is temporarily set to the half-clutched state to reduce the shock.
Half-clutched State
 The current output from the TCM to the torque converte r clutch solenoid is varied to gradually increase the
torque converter clutch solenoid pressure.
In this way, the lock-up apply pressure gradually rises and while the torque converter clutch piston is put into
half-clutched status, the torque converter clutch pi ston operating pressure is increased and the coupling is
completed smoothly.
Slip Lock-up Control
 In the slip region, the torque converter clutch solenoid current is controlled with the TCM to put it into the
half-clutched state. This absorbs the engine tor que fluctuation and lock-up operates from low speed.
This raises the fuel efficiency for 4GR and 5GR at both low speed and when the accelerator has a low
degree of opening.
Engine Brake ControlINFOID:0000000003771814
 The forward one-way clutch transmits the drive force from the engine to the rear wheels. But the reverse
drive from the rear wheels is not transmitted to the engine because the one-way clutch is idling.
Therefore, the low coast brake solenoid is operated to prevent the forward one-way clutch from idling and
the engine brake is operated in the same manner as conventionally.
 The operation of the low coast brake solenoid switches the low coast brake switching valve and controls the
coupling and releasing of the low coast brake.
The low coast brake reducing valve contro ls the low coast brake coupling force.
Control ValveINFOID:0000000003771815
FUNCTION OF CONTROL VALVE
SCIA1520E
Name Function
Torque converter regulator valve In order to prevent the pressure supplied to the torque converter from being excessive,
the line pressure is adjusted to the optimum pressure (torque converter operating pres-
sure).
Pressure regu lator valve
Pressure regulator plug
Pressure regu lator sleeve Adjusts the oil discharged from the oil pump to the optimum pressure (line pressure) for
the driving state.
Front brake control valve When the front brake is coupled, adjusts the line pressure to the optimum pressure (front
brake pressure) and supplies it to the front brake. (In 1GR, 2GR, 3GR, and 5GR, adjusts
the clutch pressure.)
Accumulator control valve Adjusts the pressure (accumulator control pressure) acting on the accumulator piston
and low coast reducing valve to the pressure appropriate to the driving state.
Revision: December 20092009 QX56

TM-116
< ECU DIAGNOSIS >
TCM
Even when the electronic circuits are normal, under special conditions (for example, when slamming on the
brake with the wheels spinning drastically and stopping t he tire rotation), the transmission can go into fail-safe
mode. If this happens, switch “OFF” the ignition switch for 10 seconds, then switch it “ON” again to return to
the normal shift pattern. Therefore, the customer's v ehicle has returned to normal, so handle according to the
“diagnostics flow” (Refer to TM-5, "Work Flow"
).
FAIL-SAFE FUNCTION
If any malfunction occurs in a sensor or solenoid, th is function controls the A/T to mark driving possible.
Output Speed Sensor
 Signals are input from two systems - from output s peed sensor installed on the transmission and from com-
bination meter so normal driving is possible even if ther e is a malfunction in one of the systems. And if output
speed sensor has unusual cases, 5GR is prohibited.
Accelerator Peda l Position Sensor
 If there is a malfunction in one of the systems, the accelerator opening angle is controlled by ECM according
to a pre-determined accelerator angle to make driving possible. And if there are malfunctions in tow sys-
tems, the engine speed is fixed by ECM to a pre-determined engine speed to make driving possible.
Throttle Position Sensor
 If there is a malfunction in one of the systems, the accelerator opening angle is controlled by ECM according
to a pre-determined accelerator angle to make driving possible. And if there are malfunctions in tow sys-
tems, the accelerator opening angle is controlled by the idle signal sent from the ECM which is based on
input indicating either idle condition or off-idle condition (pre-determined accelerator opening) in order to
make driving possible.
Transmission Range Switch
 In the unlikely event that a malfunction signal enters t he TCM, the position indicator is switched “OFF”, the
starter relay is switched “OFF” (starter starting is disabled), the back-up lamp relay switched “OFF” (back-up
lamp is OFF) and the position is fixed to the “D” range to make driving possible.
Starter Relay
 The starter relay is switched “OFF”. (Starter starting is disabled.)
Interlock
 If there is an interlock judgment malfunction, the trans mission is fixed in 2GR to make driving possible.
NOTE:
When the vehicle is driven fixed in 2GR, a input speed sensor malfunction is displayed, but this is
not a input speed sensor malfunction.
 When the interlock is detected at the 3GR or more, it is locked at the 2GR.
1st Engine Braking
 When there is an 1st gear engine brake judgment malfunc tion, the low coast brake solenoid is switched
“OFF” to avoid the engine brake operation.
Line Pressure Solenoid
 The solenoid is switched “OFF” and the line pressure is se t to the maximum hydraulic pressure to make driv-
ing possible.
Torque Converter Clutch Solenoid
 The solenoid is switched “OFF” to release the lock-up.
Low Coast Brake Solenoid
 When a (electrical or functional) malfunction occurs, in order to make driving possible, the engine brake is not applied in 1GR and 2GR.
Input Clutch Solenoid
 If a (electrical or functional) malfunction occurs with the solenoid either “ON” or “OFF”, the transmission is
held in 4GR to make driving possible.
Direct Clutch Solenoid
 If a (electrical or functional) malfunction occurs with the solenoid either “ON” or “OFF”, the transmission is
held in 4GR to make driving possible.
Front Brake Solenoid
 If a (electrical or functional) malfunction occurs with the solenoid “ON”, in order to make driving possible, the
A/T is held in 5GR; if the solenoid is OFF, 4GR.
Revision: December 20092009 QX56

TM-174
< PRECAUTION >
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000005880175
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 SR and SB section of this Service Man-
ual.
WARNING:
 To avoid rendering the SRS inopera tive, which could increase the risk of personal injury or death in
the event of a collision which 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 SR section.
 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 Airbag Diagnosis Sensor Unit or other Airbag System sensors with the Igni-
tion ON or engine running, DO NOT use air or electri c 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:0000000005880176
NOTE:
 This Procedure is applied only to models with Intelli gent Key system and NATS (NISSAN ANTI-THEFT SYS-
TEM).
 Remove and install all control units after disconnecting both battery cables with the ignition knob in the
″LOCK ″ position.
 Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If DTC is detected, perform trouble diagnosis according to self-diagnostic results.
For models equipped with the Intelligent Key system and NATS, an electrically controlled steering lock mech-
anism is adopted on the key cylinder.
For this reason, if the battery is disconnected or if the battery is discharged, the steering wheel will lock and
steering wheel rotation will become impossible.
If steering wheel rotation is required when battery pow er is interrupted, follow the procedure below before
starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Use the Intelligent Key or mechanical key to turn the ignition switch to the ″ACC ″ position. At this time, the
steering lock will be released.
3. Disconnect both battery cables. The steering lock will remain released and the steering wheel can be
rotated.
4. Perform the necessary repair operation.
Revision: December 20092009 QX56

VTL-1
VENTILATION, HEATER & AIR CONDITIONER
C
DE
F
G H
J
K L
M
SECTION VTL
A
B
VTL
N
O P
CONTENTS
VENTILATION SYSTEM
PRECAUTION ....... ........................................2
PRECAUTIONS .............................................. .....2
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
2
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect ............................... ......
2
Precaution for Working with HFC-134a (R-134a) ......3
Precaution for Procedure without Cowl Top Cover ......3
PREPARATION ............................................4
PREPARATION .............................................. .....4
Special Service Tool ........................................... ......4
Commercial Service Tool ..........................................4
FUNCTION DIAGNOSIS ...............................5
IN-CABIN MICROFILTER .............................. .....5
Description .......................................................... ......5
ON-VEHICLE MAINTENANCE .....................6
IN-CABIN MICROFILTER .............................. .....6
Removal and Installation ...........................................6
ON-VEHICLE REPAIR .... ..............................7
CONTROL UNIT ..................................................7
Removal and Installation ...........................................7
IN-VEHICLE SENSOR ................................... .....9
Removal and Installation ...........................................9
OPTICAL SENSOR ........................................ ....10
Removal and Installation .........................................10
INTAKE SENSOR ..............................................11
Removal and Installation .........................................11
BLOWER MOTOR .......................................... ....12
Component .......................................................... ....12
Removal and Installation .........................................12
IN-CABIN MICROFILTER .................................14
Removal and Installation .........................................14
HEATER & COOLING UNIT ASSEMBLY ........15
Component ..............................................................15
Removal and Installation .........................................16
HEATER CORE .................................................18
Component ..............................................................18
Removal and Installation .........................................19
DEFROSTER DOOR MOTOR ..........................21
Removal and Installation .........................................21
INTAKE DOOR MOTOR ...................................22
Removal and Installation .........................................22
MODE DOOR MOTOR ......................................23
Components ............................................................23
Removal and Installation .........................................24
AIR MIX DOOR MOTOR ...................................25
Component ..............................................................25
Removal and Installation .........................................26
VARIABLE BLOWER CONTROL .....................28
Components ............................................................28
Removal and Installation .........................................29
DUCTS AND GRILLES .....................................30
Component ..............................................................30
Removal and Installation .........................................33
REFRIGERANT LINES .....................................35
Removal and Installation for Front Evaporator ........35
Removal and Installation for Rear Evaporator .........36
Removal and Installation for Rear Expansion
Valve ........................................................................
37
Revision: December 20092009 QX56

VTL-2
< PRECAUTION >
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000005867738
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 severity 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 SR and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inopera tive, which could increase the risk of personal injury or death in
the event of a collision which would result in air bag 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 unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the SR section.
• Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harn esses can be identified 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 Airbag Diagnosis Sensor Unit or other Airbag System sensors with the Igni-
tion ON or engine running, DO NOT use air or electri c 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:0000000005867739
NOTE:
• This Procedure is applied only to models with Intelligent Key system and NATS (NISSAN ANTI-THEFT SYS-
TEM).
• Remove and install all control units after disconnecting both battery cables with the ignition knob in the
″LOCK ″ position.
• Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If DTC is detected, perform trouble diagnosis according to self-diagnostic results.
For models equipped with the Intelligent Key system and NATS, an electrically controlled steering lock mech-
anism is adopted on the key cylinder.
For this reason, if the battery is disconnected or if the battery is discharged, the steering wheel will lock and
steering wheel rotation will become impossible.
If steering wheel rotation is required when battery pow er is interrupted, follow the procedure below before
starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Use the Intelligent Key or mechanical key to turn the ignition switch to the ″ACC ″ position. At this time, the
steering lock will be released.
3. Disconnect both battery cables. The steering lock will remain released and the steering wheel can be rotated.
4. Perform the necessary repair operation.
Revision: December 20092009 QX56

VTL-12
< ON-VEHICLE REPAIR >
BLOWER MOTOR
BLOWER MOTOR
ComponentINFOID:0000000003775265
Front Blower MotorRear Blower Motor
Removal and InstallationINFOID:0000000003775266
FRONT BLOWER MOTOR
Removal
1. Remove the instrument lower panel RH and glove box assembly. Refer to IP-17, "Removal and Installa-
tion".
2. Disconnect the front blower motor electrical connector.
3. Remove the three screws and remove the front blower motor.
4. Remove blower motor wheel as necessary to transfer to new blower motor.
Installation
LJIA0136E
1. Front heater and cooling unit assembly 2. Front blower motor 3. Front variable blower control
AWIIA0085ZZ
1. Rear blower motor2. Rear heater and cooling unit assembly 3. Rear variable blower control
Revision: December 20092009 QX56

BLOWER MOTORVTL-13
< ON-VEHICLE REPAIR >
C
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F
G H
J
K L
M A
B
VTL
N
O P
Installation is in the reverse order of removal.
REAR BLOWER MOTOR
Removal
1. Remove the rear heater and cooling unit assembly. Refer to VTL-16, "Removal and Installation".
2. Disconnect the rear blower motor electrical connector.
3. Remove the three screws and remove the rear blower motor.
4. Remove blower motor wheel as necessary to transfer to new blower motor.
Installation
Installation is in the reverse order of removal.
Revision: December 20092009 QX56

WT-1
SUSPENSION
C
DF
G H
I
J
K L
M
SECTION WT
A
B
WT
N
O PCONTENTS
ROAD WHEELS & TIRES
BASIC INSPECTION ....... .............................3
DIAGNOSIS AND REPAIR WORKFLOW ..... .....3
Repair Work Flow ................................................ ......3
INSPECTION AND ADJUSTMENT .....................5
Preliminary Check ............................................... ......5
Transmitter Wake Up Operation ...............................5
ID Registration Procedure .........................................6
FUNCTION DIAGNOSIS ...............................8
TPMS .............................................................. .....8
System Diagram .................................................. ......8
System Description ...................................................8
System Component .................................................10
DIAGNOSIS SYSTEM (BCM) ............................11
CONSULT-III Function (BCM) ............................. ....11
Self-Diagnosis (With CONSULT-III) ........................12
Self-Diagnosis (Without CONSULT-III) ...................13
COMPONENT DIAGNOSIS .........................14
C1708 - C1711 DATA FROM TRANSMITTER
NOT BEING RECEIVED ................................. ....
14
Description .......................................................... ....14
DTC Logic ...............................................................14
Data from Transmitter Not Being Received ............14
Special Repair Requirement ...................................15
C1712 - C1715, C1720 - C1723, C1724 -
C1727 TRANSMITTER MALFUNCTION ....... ....
16
Description .......................................................... ....16
DTC Logic ...............................................................16
Transmitter Malfunction ...........................................16
Special Repair Requirement ...................................17
C1716 - C1719 TRANSMITTER PRESSURE
MALFUNCTION .............................................. ....
18
Description .......................................................... ....18
DTC Logic ...............................................................18
Transmitter Pressure Malfunction ............................18
Special Repair Requirement ................................ ....18
C1729 VEHICLE SPEED SIGNAL ....................19
Description ...............................................................19
DTC Logic ................................................................19
Vehicle Speed Signal ..............................................19
C1735 IGNITION SIGNAL .................................20
Description ...............................................................20
DTC Logic ................................................................20
Diagnosis Procedure ...............................................20
ECU DIAGNOSIS .........................................21
BCM (BODY CONTROL MODULE) .................21
Reference Value .................................................. ....21
Wiring Diagram ........................................................23
Self-Diagnosis (With CONSULT-III) ........................26
Self-Diagnosis (Without CONSULT-III) ...................27
SYMPTOM DIAGNOSIS ..............................29
TPMS .................................................................29
Symptom Table ................................................... ....29
LOW TIRE PRESSURE WARNING LAMP
DOES NOT TURN ON .......................................
30
Low Tire Pressure Warning Lamp Does Not Come
On When Ignition Switch Is Turned On ...................
30
LOW TIRE PRESSURE WARNING LAMP
STAYS ON ........................................................
31
Low Tire Pressure Warning Lamp Stays On When
Ignition Switch Is Turned On ............................... ....
31
LOW TIRE PRESSURE WARNING LAMP
BLINKS .............................................................
32
Low Tire Pressure Warning Lamp Flashes When
Ignition Switch Is Turned On ...................................
32
HAZARD WARNING LAMPS FLASH ..............33
Revision: December 20092009 QX56