2008 INFINITI QX56 fl sensor

STR-2
< PRECAUTION >
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000004857581
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:0000000004857584
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: March 2010 2008 QX56

PRECAUTIONSSTR-3
< PRECAUTION >
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5. When the repair work is completed, return the ignition switch to the
″LOCK ″ position before connecting
the battery cables. (At this time, the steering lock mechanism will engage.)
6. Perform a self-diagnosis check of al l control units using CONSULT-III.
Precaution for Power Generation Variable Voltage Control SystemINFOID:0000000001538874
CAUTION:
For this model, the battery current sensor that is installed to the negative battery cable measures the
charging/discharging current of the battery and performs various engine controls. If an electrical com-
ponent is connected directly to the negative battery terminal, the current flowing through that compo-
nent will not be measured by the battery current sensor. This condition may cause a malfunction of
the engine control system and battery discharge m ay occur. Do not connect an electrical component
or ground wire directly to the battery terminal.
Revision: March 2010 2008 QX56

TM-1
TRANSMISSION & DRIVELINE
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CONTENTS
TRANSAXLE & TRANSMISSION
BASIC INSPECTION ....... .............................5
DIAGNOSIS AND REPAIR WORKFLOW ..... .....5
Work Flow ........................................................... ......5
Diagnostic Work Sheet ..............................................6
FUNCTION DIAGNOSIS ...............................8
A/T CONTROL SYSTEM ................................ .....8
Cross-Sectional View (2WD models) .................. ......8
Cross-Sectional View (4WD models) ........................9
Shift Mechanism ........................................................9
TCM Function ..........................................................20
CAN Communication ...............................................21
Input/Output Signal of TCM .....................................22
Line Pressure Control .............................................22
Shift Control ........................................................ ....24
Lock-up Control .......................................................25
Engine Brake Control ..............................................26
Control Valve ...........................................................26
Component Parts Location ......................................28
A/T SHIFT LOCK SYSTEM ............................ ....29
System Description ............................................. ....29
Component Parts Location ......................................29
ON BOARD DIAGNOSTIC (OBD) SYSTEM ......30
Introduction ......................................................... ....30
OBD-II Function for A/T System ..............................30
One or Two Trip Detection Logic of OBD-II ............30
OBD-II Diagnostic Trouble Code (DTC) ..................30
Malfunction Indicator Lamp (MIL) ............................31
DIAGNOSIS SYSTEM (TCM) .............................32
CONSULT-III Function (TRANSMISSION) ......... ....32
COMPONENT DIAGNOSIS .........................38
U1000 CAN COMM CI RCUIT .............................38
Description .......................................................... ....38
On Board Diagnosis Logic ......................................38
Possible Cause .......................................................38
DTC Confirmation Procedure .............................. ....38
Diagnosis Procedure ...............................................38
P0615 STARTER RELAY .................................39
Description ...............................................................39
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ....
39
On Board Diagnosis Logic .......................................39
Possible Cause ........................................................39
DTC Confirmation Procedure ..................................39
Diagnosis Procedure ...............................................39
P0700 TRANSMISSION CONTROL .................42
Description ...............................................................42
On Board Diagnosis Logic .......................................42
Possible Cause ........................................................42
DTC Confirmation Procedure ..................................42
Diagnosis Procedure ...............................................42
P0705 TRANSMISSION RANGE SWITCH A ...43
Description ...............................................................43
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ....
43
On Board Diagnosis Logic .......................................43
Possible Cause ........................................................43
DTC Confirmation Procedure ..................................43
Diagnosis Procedure ...............................................43
P0717 INPUT SPEED SENSOR A ....................46
Description ...............................................................46
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ....
46
On Board Diagnosis Logic .......................................46
Possible Cause ........................................................46
DTC Confirmation Procedure ..................................46
Diagnosis Procedure ...............................................46
P0720 OUTPUT SPEED SENSOR ...................48
Description ...............................................................48
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ....
48
On Board Diagnosis Logic .......................................48
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TM-2
Possible Cause .......................................................48
DTC Confirmation Procedure .................................48
Diagnosis Procedure ..............................................49
P0725 ENGINE SPEED .....................................51
Description ........................................................... ...51
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ...
51
On Board Diagnosis Logic ......................................51
Possible Cause .......................................................51
DTC Confirmation Procedure .................................51
Diagnosis Procedure ..............................................51
P0731 1GR INCORRECT RATIO ......................53
Description ........................................................... ...53
On Board Diagnosis Logic ......................................53
Possible Cause .......................................................53
DTC Confirmation Procedure .................................53
Diagnosis Procedure ..............................................54
P0732 2GR INCORRECT RATIO ......................55
Description ........................................................... ...55
On Board Diagnosis Logic ......................................55
Possible Cause .......................................................55
DTC Confirmation Procedure .................................55
Diagnosis Procedure ..............................................56
P0733 3GR INCORRECT RATIO ......................57
Description ........................................................... ...57
On Board Diagnosis Logic ......................................57
Possible Cause .......................................................57
DTC Confirmation Procedure .................................57
Diagnosis Procedure ..............................................58
P0734 4GR INCORRECT RATIO ......................59
Description ........................................................... ...59
On Board Diagnosis Logic ......................................59
Possible Cause .......................................................59
DTC Confirmation Procedure .................................59
Diagnosis Procedure ..............................................60
P0735 5GR INCORRECT RATIO ......................61
Description ........................................................... ...61
On Board Diagnosis Logic ......................................61
Possible Cause .......................................................61
DTC Confirmation Procedure .................................61
Diagnosis Procedure ..............................................62
P0740 TORQUE CONVERTER .........................63
Description ........................................................... ...63
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ...
63
On Board Diagnosis Logic ......................................63
Possible Cause .......................................................63
DTC Confirmation Procedure .................................63
Diagnosis Procedure ..............................................63
P0744 TORQUE CONVERTER .........................65
Description ........................................................... ...65
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ...
65
On Board Diagnosis Logic ................................... ...65
Possible Cause .......................................................65
DTC Confirmation Procedure ..................................65
Diagnosis Procedure ...............................................66
P0745 PRESSURE CONTROL SOLENOID A ...67
Description ........................................................... ...67
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ...
67
On Board Diagnosis Logic ......................................67
Possible Cause .......................................................67
DTC Confirmation Procedure ..................................67
Diagnosis Procedure ...............................................67
P1705 TP SENSOR ...........................................69
Description ..............................................................69
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ...
69
On Board Diagnosis Logic ......................................69
Possible Cause .......................................................69
DTC Confirmation Procedure ..................................69
Diagnosis Procedure ...............................................69
P1710 TRANSMISSION FLUID TEMPERA-
TURE SENSOR .................................................
71
Description ........................................................... ...71
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ...
71
On Board Diagnosis Logic ......................................71
Possible Cause .......................................................71
DTC Confirmation Procedure ..................................71
Diagnosis Procedure ...............................................71
Component Inspection ............................................73
P1721 VEHICLE SPEED SIGNAL ....................74
Description ..............................................................74
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ...
74
On Board Diagnosis Logic ......................................74
Possible Cause .......................................................74
DTC Confirmation Procedure ..................................74
Diagnosis Procedure ...............................................74
P1730 INTERLOCK ...........................................76
Description ..............................................................76
On Board Diagnosis Logic ......................................76
Possible Cause .......................................................76
DTC Confirmation Procedure ..................................76
Judgement of Interlock ............................................76
Diagnosis Procedure ............................................ ...76
P1731 1ST ENGINE BRAKING .........................78
Description ........................................................... ...78
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ...
78
On Board Diagnosis Logic ......................................78
Possible Cause .......................................................78
DTC Confirmation Procedure ..................................78
Diagnosis Procedure ...............................................78
Revision: March 2010 2008 QX56

TM-4
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ................................................................
173
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect .................................
173
Precaution for On Board Diagnosis (OBD) System
of A/T and Engine ..................................................
174
Precaution .............................................................174
Service Notice or Precaution .................................175
PREPARATION ..........................................176
PREPARATION .............................................. .176
Special Service Tool ............................................ ..176
Commercial Service Tool ......................................177
ON-VEHICLE MAINTENANCE ..................178
A/T FLUID ....................................................... .178
Checking the A/T Fluid (ATF) .............................. ..178
Changing the A/T Fluid (ATF) ................................180
A/T FLUID COOLER ........................................182
A/T Fluid Cooler Cleaning ................................... ..182
Inspection ..............................................................184
STALL TEST ....................................................185
Inspection and Judgment .................................... ..185
LINE PRESSURE TEST ..................................187
Inspection and Judgment .................................... ..187
ROAD TEST .....................................................189
Description ........................................................... ..189
Check Before Engine Is Started ............................189
Check At Idle ....................................................... ..189
Cruise Test - Part 1 ...............................................190
Cruise Test - Part 2 ...............................................192
Cruise Test - Part 3 ...............................................193
Vehicle Speed When Shifting Gears .....................193
Vehicle Speed When Performing and Releasing
Complete Lock-up .................................................
193
A/T POSITION .................................................194
Checking of A/T Position ..................................... ..194
Adjustment of A/T Position ....................................194
ON-VEHICLE REPAIR ...............................195
SHIFT CONTROL SYSTEM ........................... .195
A/T Shift Selector Removal and Installation ..........195
Checking of A/T Position ..................................... ..196
Adjustment of A/T Position ....................................196
AIR BREATHER HOSE ...................................197
Removal and Installation ..................................... ..197
OIL PAN ...........................................................199
Oil Pan ................................................................. .199
CONTROL VALVE WITH TCM ........................201
Control Valve with TCM and A/T Fluid Tempera-
ture Sensor 2 ....................................................... .
201
REAR OIL SEAL ..............................................213
Rear Oil Seal ........................................................ .213
REMOVAL AND INSTALLATION .............214
TRANSMISSION ASSEMBLY ........................ ..214
Removal and Installation (2WD) .......................... .214
Removal and Installation (4WD) ...........................216
DISASSEMBLY AND ASSEMBLY ...........220
OVERHAUL ......................................................220
Component .......................................................... .220
Oil Channel ...........................................................227
Location of Adjusting Shims, Needle Bearings,
Thrust Washers and Snap Rings ......................... .
229
DISASSEMBLY .............................................. ..232
Disassembly ......................................................... .232
REPAIR FOR COMPONENT PARTS ..............250
Oil Pump .............................................................. .250
Front Sun Gear, 3rd One-Way Clutch ...................252
Front Carrier, Input Clutch, Rear Internal Gear .....254
Mid Sun Gear, Rear Sun Gear, High and Low Re-
verse Clutch Hub ................................................. .
259
High and Low Reverse Clutch ..............................264
Direct Clutch .........................................................266
ASSEMBLY .................................................... ..269
Assembly (1) ........................................................ .269
Adjustment ............................................................282
Assembly (2) .........................................................284
SERVICE DATA AND SPECIFICATIONS
(SDS) ........ .................................................
291
SERVICE DATA AND SPECIFICATIONS
(SDS) .............................................................. ..
291
General Specification ........................................... .291
Vehicle Speed at Which Gear Shifting Occurs .....291
Vehicle Speed at Which Lock-up Occurs/Releas-
es ......................................................................... .
291
Stall Speed ............................................................292
Line Pressure ........................................................292
A/T Fluid Temperature Sensor ..............................292
Input Speed Sensor ..............................................292
Output Speed Sensor ...........................................292
Reverse Brake ......................................................292
Total End Play .......................................................292
Torque Converter ..................................................293
Revision: March 2010 2008 QX56

DIAGNOSIS AND REPAIR WORKFLOWTM-5
< BASIC INSPECTION >
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BASIC INSPECTION
DIAGNOSIS AND REPAIR WORKFLOW
Work FlowINFOID:0000000001603985
INTRODUCTION
The TCM receives a signal from the output speed sensor, accelera-
tor pedal position sensor (throttle position sensor) or transmission
range switch. Then provides shift c ontrol or lock-up control via A/T
solenoid valves.
The TCM also communicates with the ECM by means of a signal
sent from sensing elements used wit h the OBD-related parts of the
A/T system for malfunction-diagnostic purposes. The TCM is capa-
ble of diagnosing malfunctioning parts while the ECM can store mal-
functions in its memory.
Input and output signals must always be correct and stable in the
operation of the A/T system. T he A/T system must be in good oper-
ating condition and be free of valve seizure, solenoid valve malfunc-
tion, etc.
It is much more difficult to diagnose an error that occurs intermit-
tently rather than continuously. Most intermittent errors are caused
by poor electric connections or impr oper wiring. In this case, careful
checking of suspected circuits may help prevent the replacement of
good parts.
A visual check only may not find t he cause of the errors. A road test
with CONSULT-III (or GST) or a circuit tester connected should be
performed. Follow the “DETAILED FLOW”.
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such errors, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “Diagnostic work sheet” as shown on
the example (Refer to TM-6
) should be used.
Start your diagnosis by looking for “conventional” errors first. This will
help troubleshoot driveability errors on an electronically controlled
engine vehicle.
Also check related Service bulletins.
DETAILED FLOW
1.COLLECT THE INFORMATION FROM THE CUSTOMER
Get the detailed information from the customer about the symptom (the condition and the environment when
the incident/malfunction occurred) us ing diagnosis worksheet. Refer to TM-6, "
Diagnostic Work Sheet".
>> GO TO 2.
2.CHECK SYMPTOM 1
Check the following items based on the in formation obtained from the customer.
• Fail-safe. Refer to TM-114, "
Fail-Safe".
• A/T fluid inspection. Refer to TM-178, "
Checking the A/T Fluid (ATF)".
• Stall test. Refer to TM-185, "
Inspection and Judgment".
• Line pressure test. Refer to TM-187, "
Inspection and Judgment".
SAT631IB
SAT632I
SEF234G
Revision: March 2010 2008 QX56

TM-20
< FUNCTION DIAGNOSIS >
A/T CONTROL SYSTEM
TCM Function
INFOID:0000000001603990
The function of the TCM is to:
• Receive input signals sent from various switches and sensors.
• Determine required line pressure, shifting poi nt, lock-up operation, and engine brake operation.
• Send required output signals to the respective solenoids.
CONTROL SYSTEM OUTLINE
The automatic transmission senses vehicle operating conditions through vari ous sensors or signals. It always
controls the optimum shift position and reduces shifting and lock-up shocks.
1. Front brake 2. Input clutch3. Direct clutch
4. High and low reverse clutch 5. Reverse brake 6. Forward brake
7. Low coast brake 8. 1st one-way clutch 9. Forward one-way clutch
10. 3rd one-way clutch 11. Front sun gear12. Input shaft
13. Mid internal gear 14. Front internal gear15. Rear carrier
16. Rear sun gear 17. Mid sun gear18. Front carrier
19. Mid carrier 20. Rear internal gear21. Output shaft
22. Parking gear 23. Parking pawl
SCIA1519E
Revision: March 2010 2008 QX56

A/T CONTROL SYSTEMTM-21
< FUNCTION DIAGNOSIS >
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CONTROL SYSTEM DIAGRAM
CAN CommunicationINFOID:0000000001603991
SYSTEM DESCRIPTION
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only. For details, refer to LAN-4,
"System Description".
SENSORS (or SIGNALS)
⇒TCM
⇒ACTUATORS
Transmission range switch
Accelerator pedal position sensor
Closed throttle position signal
Wide open throttle position signal
Engine speed signal
A/T fluid temperature sensor
Output speed sensor
Vehicle speed signal
Stop lamp switch signal
Input speed sensor
1st position switch signal
4th position switch signal
ATF pressure switch 2 signal
Tow mode switch signal Shift control
Line pressure control
Lock-up control
Engine brake control
Timing control
Fail-safe control
Self-diagnosis
CONSULT-III co
mmunication
line
Duet-EA control
CAN system Input clutch solenoid valve
Direct clutch solenoid valve
Front brake solenoid valve
High and low reverse clutch sole-
noid valve
Low coast brake solenoid valve
Torque converter clutch solenoid
valve
Line pressure solenoid valve
A/T CHECK indicator lamp
Starter relay
Back-up lamp relay
JSDIA1315GB
Revision: March 2010
2008 QX56