2006 INFINITI QX56 automatic transmission

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QUICK REFERENCE INDEX
AGENERAL INFORMATIONGIGeneral Information
BENGINEEMEngine Mechanical
LUEngine Lubrication System
COEngine Cooling System
ECEngine Control System
FLFuel System
EXExhaust System
ACCAccelerator Control System
CTRANSMISSION/
TRANSAXLEATAutomatic Transmission
DDRIVELINE/AXLETFTransfer
PRPropeller Shaft
FFDFront Final Drive
RFDRear Final Drive
FAXFront Axle
RAXRear Axle
ESUSPENSIONFSUFront Suspension
RSURear Suspension
WTRoad Wheels & Tires
FBRAKESBRBrake System
PBParking Brake System
BRCBrake Control System
GSTEERINGPSPower Steering System
HRESTRAINTSSBSeat Belts
SRSSupplemental Restraint System (SRS)
IBODYBLBody, Lock & Security System
GWGlasses, Window System & Mirrors
RFRoof
EIExterior & Interior
IPInstrument Panel
SESeat
APAdjustable Pedal
JAIR CONDITIONERATCAutomatic Air Conditioner
KELECTRICALSCStarting & Charging System
LTLighting System
DIDriver Information System
WWWiper, Washer & Horn
BCSBody Control System
LANLAN System
AVAudio Visual, Navigation & Telephone System
ACSAuto Cruise Control System
PGPower Supply, Ground & Circuit Elements
LMAINTENANCEMAMaintenance
MINDEXIDXAlphabetical Index
Edition: July 2005
Revision: November 2009
Publication No. SM6E-1J60U2
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© 2009 NISSAN NORTH AMERICA, INC.
All rights reserved. No part of this Service Manual may be reproduced or stored in a retrieval system, or transmitted in any
form, or by any means, electronic, mechanical, photo-copying, recording or otherwise, without the prior written permission
of Nissan North America, Inc.
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2006
QUICK REFERENCE CHART: QX56

Front Disc Brake - Repair LimitsELS001QU
Rear Disc Brake - Repair LimitsELS001QU
Brake PedalELS001QV
Unit: mm (in)
Refill CapacitiesELS001QW
Brake modelCLZ31VCAD41VA
Brake pad Standard thickness (new)
11.88 mm (0.468 in)12 mm (0.47 in)
Repair limit thickness 1.0 mm (0.039 in)1.0 mm (0.039 in)
Disc rotor Standard thickness (new)
26.0 mm (1.024 in) 30.0 mm (1.181 in)
Repair limit thickness 24.5 mm (0.965 in) 28.5 mm (1.122 in)
Maximum uneven wear (measured at 8 positions) 0.015 mm (0.0006 in)
Runout limit (with it attached to the vehicle) 0.03 mm (0.001 in)
Brake model AD14VE
Brake pad Standard thickness (new)
12.13 mm (0.478 in)
Repair limit thickness 1.0 mm (0.039 in)
Disc rotor Standard thickness (new)
14.0 mm (0.551 in)
Repair limit thickness 12.0 mm (0.472 in)
Maximum uneven wear (measured at 8 positions) 0.015 mm (0.0006 in)
Runout limit (with it attached to the vehicle) 0.05 mm (0.002 in)
Brake pedal height (from dash panel top surface) 182.3 − 192.3 (7.18 − 7.57)
Depressed pedal height [under a force of 490 N (50 kg, 110 lb) with engine running] More than 90.3 (3.55)
Clearance between stopper rubber and the threaded end of stop lamp switch 0.74 − 1.96 (0.029 − 0.077)
Pedal play 3 − 11 (0.12 − 0.43)
Description Capacity (Approximate)
Metric US measure Imp measure
Fuel 105.8 28 gal 23 1/4 gal
Engine oil
(drain and refill) With oil filter change
6.2 6 1/2 qt 5 1/2 qt
Without oil filter change 5.9 6 1/4 qt 5 1/4 qt
Dry engine (engine overhaul) 7.6 8 qt
6 3/4 qt
Cooling system With reservoir at MAX level
14.4 3 3/4 gal 3 1/8 gal
Automatic transmission fluid (ATF) 10.6 11 1/4 qt 9 3/8 qt
Rear final drive oil 1.75 3 3/4 pt 3 1/8 pt
Transfer fluid 3.0 3 1/8 qt 2 5/8 qt
Front final drive oil 1.6 3 3/8 pt 2 7/8 pt
Power steering fluid (PSF) 1.0 2 1/8 pt 1 3/4 pt
Windshield washer fluid 4.5 1 1/4 gal 1 gal
Air conditioning system refrigerant 1.08 ± 0.05 kg 2.38 ± 0.11 lb 2.38 ± 0.11 lb
Air conditioning system lubricants 290 m9.8 fl oz 10.2 fl oz

AT-1
AUTOMATIC TRANSMISSION
C TRANSMISSION/TRANSAXLE
CONTENTS
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SECTION
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Revision: November 2009 2006 QX56
INDEX FOR DTC ...................................................
..... 5
Alphabetical Index ............................................... ..... 5
DTC No. Index .................................................... ..... 6
PRECAUTIONS ..................................................... ..... 7
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” ............................................................. ..... 7
Precautions for On Board Diagnostic (OBD) System
of A/T and Engine .................................................... 7
Precautions ......................................................... ..... 8
Service Notice or Precautions ............................. ..... 9
PREPARATION ...................................................... ... 10
Special Service Tools .......................................... ... 10
Commercial Service Tools ................................... .... 11
A/T FLUID .............................................................. ... 12
Changing Automatic Transmission Fluid (ATF) ... ... 12
Checking Automatic Transmission Fluid (ATF) ... ... 12
A/T Fluid Cooler Cleaning ................................... ... 14
A/T CONTROL SYSTEM ....................................... ... 17
Cross-Sectional View (2WD models) .................. ... 17
Cross-Sectional View (4WD models) .................. ... 18
Shift Mechanism .................................................. ... 19
TCM Function ...................................................... ... 30
CAN Communication ........................................... ... 31
Input/Output Signal of TCM ................................. ... 31
Line Pressure Control ......................................... ... 32
Shift Control ........................................................ ... 33
Lock-up Control ................................................... ... 34
Engine Brake Control .......................................... ... 36
Control Valve ....................................................... ... 36
ON BOARD DIAGNOSTIC (OBD) SYSTEM ......... ... 38
Introduction ......................................................... ... 38
OBD-II Function for A/T System .......................... ... 38
One or Two Trip Detection Logic of OBD-II ......... ... 38
OBD-II Diagnostic Trouble Code (DTC) .............. ... 38
Malfunction Indicator Lamp (MIL) ........................ ... 41
TROUBLE DIAGNOSIS ......................................... ... 42
DTC Inspection Priority Chart ............................. ... 42
Fail-Safe .............................................................. ... 42
How To Perform Trouble Diagnosis For Quick and Accurate Repair ...................................................
... 44
A/T Electrical Parts Location ............................... ... 49
Circuit Diagram ....................................................... 50
Inspections Before Trouble Diagnosis ................. ... 51
Check Before Engine is Started ........................... ... 55
Check at Idle ........................................................... 55
Cruise Test - Part 1 .............................................. ... 56
Cruise Test - Part 2 .............................................. ... 58
Cruise Test - Part 3 .............................................. ... 59
Vehicle Speed When Shifting Gears ................... ... 60
Vehicle Speed When Performing and Releasing
Complete Lock-up .................................................. 60
Vehicle Speed When Performing and Releasing
Slip Lock-up ............................................................ 60
Symptom Chart ....................................................... 61
TCM Input/Output Signal Reference Values ........ ... 83
CONSULT-II Function (A/T) ................................. ... 84
DTC U1000 CAN COMMUNICATION LINE ........... ... 96
Description ........................................................... ... 96
On Board Diagnosis Logic ................................... ... 96
Possible Cause ....................................................... 96
DTC Confirmation Procedure .............................. ... 96
Wiring Diagram — AT — CAN ............................. ... 97
Diagnostic Procedure .......................................... ... 99
DTC P0615 START SIGNAL CIRCUIT .................. .100
Description ........................................................... .100
CONSULT-II Reference Value ............................. .100
On Board Diagnosis Logic ................................... .100
Possible Cause .................................................... .100
DTC Confirmation Procedure .............................. .100
Wiring Diagram — AT — STSIG ......................... .101
Diagnostic Procedure .......................................... .102
DTC P0700 TCM .................................................... .104
Description ........................................................... .104
On Board Diagnosis Logic ................................... .104
Possible Cause .................................................... .104
DTC Confirmation Procedure .............................. .104
Diagnostic Procedure .......................................... .104
DTC P0705 PARK/NEUTRAL POSITION SWITCH .105
Description ........................................................... .105

AT-8
PRECAUTIONS
Revision: November 20092006 QX56
Precautions ECS00CDL

Before connecting or disconnecting the A/T assembly har-
ness connector, turn ignition switch “OFF” and disconnect
negative battery cable. Because battery voltage is applied
to TCM even if ignition switch is turned “OFF”.

After performing each TROUBLE DIAGNOSIS, perform
“DTC (Diagnostic Trouble Code) CONFIRMATION PROCE-
DURE”.
If the repair is completed the DTC should not be displayed
in the “DTC CONFIRMATION PROCEDURE”.

Always use the specified brand of ATF. Refer to MA-11, "RECOMMENDED FLUIDS AND LUBRICANTS" .

Use paper rags not cloth rags during work.

After replacing the ATF, dispose of the waste oil using the methods prescribed by law, ordinance, etc.

Before proceeding with disassembly, thoroughly clean the outside of the transmission. It is important to
prevent the internal parts from becoming contaminated by dirt or other foreign matter.

Disassembly should be done in a clean work area.

Use lint-free cloth or towels for wiping parts clean. Common shop rags can leave fibers that could interfere
with the operation of the transmission.

Place disassembled parts in order for easier and proper assembly.

All parts should be carefully cleaned with a general purpose, non-flammable solvent before inspection or
reassembly.

Gaskets, seals and O-rings should be replaced any time the transmission is disassembled.

It is very important to perform functional tests whenever they are indicated.

The valve body contains precision parts and requires extreme care when parts are removed and serviced.
Place disassembled valve body parts in order for easier and proper assembly. Care will also prevent
springs and small parts from becoming scattered or lost.

Properly installed valves, sleeves, plugs, etc. will slide along bores in valve body under their own weight.

Before assembly, apply a coat of recommended ATF to all parts. Apply petroleum jelly to protect O-rings
and seals, or hold bearings and washers in place during assembly. Do not use grease.

Extreme care should be taken to avoid damage to O-rings, seals and gaskets when assembling.

Clean or replace ATF cooler if excessive foreign material is found in oil pan or clogging strainer. Refer to
AT- 1 4 , "
A/T Fluid Cooler Cleaning" .

After overhaul, refill the transmission with new ATF.

When the A/T drain plug is removed, only some of the fluid is drained. Old A/T fluid will remain in torque
converter and ATF cooling system.
Always follow the procedures under “Changing A/T Fluid” in the AT section when changing A/T fluid. Refer
to AT- 1 2 , "
Changing Automatic Transmission Fluid (ATF)" , AT- 1 2 , "Checking Automatic Transmission
Fluid (ATF)" .
SEF289H
SEF217U

AT-12
A/T FLUID
Revision: November 20092006 QX56
A/T FLUIDPFP:KLE40
Changing Automatic Transmission Fluid (ATF)ECS00EPX
1. Drive the vehicle to warm up the ATF to 80° C (176 ° F).
2. Stop the engine.
3. Remove the ATF level gauge bolt.
4. Drain the ATF from the drain plug hole and then install the drain plug with a new gasket. Refill the transmission with new ATF.
Always refill with the same volume as the drained ATF. Use the
ATF level gauge to check the ATF level as shown. Add ATF as
necessary.

To flush out the old ATF from the coolers, pour new ATF into the charging pipe with the engine idling
and at the same time drain the old ATF from the auxiliary transmission oil cooler hose return line.

When the color of the ATF coming out of the auxiliary transmission oil cooler hose return line is about
the same as the color of the new ATF, flushing out the old ATF is complete. The amount of new trans-
mission ATF used for flushing should be 30% to 50% of the specified capacity.
CAUTION:

Use only the specified ATF. Do not mix with other fluids.

Using an ATF other than the specified ATF will cause deterioration in driveability and automatic
transmission durability, and may damage the automatic transmission, which is not covered by
the warranty.

When filling the transmission with ATF, do not spill the ATF on any heat generating parts such
as the exhaust manifold.

Do not reuse the drain plug gasket.
5. Install the ATF level gauge in the ATF charging pipe and tighten the level gauge bolt to specification.
6. Drive the vehicle to warm up the ATF to 80 ° C (176 ° F).
7. Check the ATF level and condition. Refer to AT- 1 2 , "
Checking Automatic Transmission Fluid (ATF)" . If the
ATF is still dirty, repeat steps 2 through 5.
Checking Automatic Transmission Fluid (ATF)ECS00EPY
1. Remove the ATF level gauge bolt.
2. Before driving, the ATF level can be checked at ATF tempera- tures of 30 ° to 50 °C (86 ° to 122 °F) using the “COLD” range on
the ATF level gauge as follows:
a. Park the vehicle on a level surface and set the parking brake.
b. Start the engine and move the selector lever through each gear position. Shift the selector lever into the “P” position.
c. Check the ATF level with the engine idling.
d. Remove the ATF level gauge and wipe it clean with a lint-free paper.
CAUTION:
When wiping the ATF from the ATF level gauge, always use
a lint-free paper, not a cloth.Drain plug : Refer to
AT- 2 5 0 , "
Components" .
WLIA0014E
ATF type and capacity : Refer to MA-11, "Fluids and Lubricants" .
Drain plug : Refer to AT- 2 5 0 , "
Components" .
Level gauge bolt : Refer to AT- 2 5 0 , "
Components" .
WLIA0014E

AT-14
A/T FLUID
Revision: November 20092006 QX56

To check the ATF level, insert the ATF level gauge until
the cap contacts the top of the charging pipe, with the
gauge reversed from the normal inserted position as
shown.
8. Check the ATF condition.

If the ATF is very dark or has some burned smell, there may be an internal problem with the transmis-
sion. Refer to AT- 1 7 6 , "
TROUBLE DIAGNOSIS FOR SYMPTOMS" . Flush the transmission cooling
system after repairing the transmission.

If the ATF contains frictional material (clutches, bands, etc.), replace the radiator and flush the transmis-
sion cooler lines using cleaning solvent and compressed air after repairing the transmission.
9. Install the ATF level gauge in the ATF charging pipe and install the level gauge bolt.
10. Tighten the level gauge bolt to specification.
A/T Fluid Cooler CleaningECS00CDS
Whenever an automatic transmission is repaired, overhauled, or replaced, the A/T fluid cooler mounted in the
radiator must be inspected and cleaned.
Metal debris and friction material, if present, can become trapped in the A/T fluid cooler. This debris can con-
taminate the newly serviced A/T or, in severe cases, can block or restrict the flow of A/T fluid. In either case,
malfunction of the newly serviced A/T may result.
Debris, if present, may build up as A/T fluid enters the cooler inlet. It will be necessary to back flush the cooler
through the cooler outlet in order to flush out any built up debris.
A/T FLUID COOLER CLEANING PROCEDURE
1. Position an oil pan under the automatic transmission's inlet and outlet cooler hoses.
2. Identify the inlet and outlet fluid cooler hoses.
3. Disconnect the fluid cooler inlet and outlet rubber hoses from the steel cooler tubes or bypass valve.
NOTE:
Replace the cooler hoses if rubber material from the hose
remains on the tube fitting.
4. Allow any A/T fluid that remains in the cooler hoses to drain into the oil pan.
5. Insert the extension adapter hose of a can of Transmission Cooler Cleaner (Nissan P/N 999MP-AM006) into the cooler out-
let hose.
CAUTION:

Wear safety glasses and rubber gloves when spraying
the Transmission Cooler Cleaner.

Spray cooler cleaner only with adequate ventilation.

Avoid contact with eyes and skin.

Do not breath vapors or spray mist.
SCIA1684E
Level gauge bolt: : Refer to AT- 2 5 0 , "Components" .
SCIA3830E
SCIA3831E

A/T FLUIDAT-15
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6. Hold the hose and can as high as possible and spray Transmission Cooler Cleaner in a continuous
stream into the cooler outlet hose until fluid flows out of the cooler inlet hose for 5 seconds.
7. Insert the tip of an air gun into the end of the cooler outlet hose.
8. Wrap a shop rag around the air gun tip and of the cooler outlet hose.
9. Blow compressed air regulated to 5 - 9 kg/cm
2 (70 - 130 psi) through the cooler outlet hose for 10 sec-
onds to force out any remaining fluid.
10. Repeat steps 5 through 9 three additional times.
11. Position an oil pan under the banjo bolts that connect the fluid cooler steel lines to the transmission.
12. Remove the banjo bolts.
13. Flush each steel line from the cooler side back toward the transmission by spraying Transmission Cooler Cleaner in a continuous stream for 5 seconds.
14. Blow compressed air regulated to 5 - 9 kg/cm
2 (70 - 130 psi) through each steel line from the cooler side
back toward the transmission for 10 seconds to force out any remaining fluid.
15. Ensure all debris is removed from the steel cooler lines.
16. Ensure all debris is removed from the banjo bolts and fittings.
17. Perform AT- 1 4 , "
A/T FLUID COOLER CLEANING PROCEDURE" .
A/T FLUID COOLER DIAGNOSIS PROCEDURE
NOTE:
Insufficient cleaning of the cooler inlet hose exterior may lead to inaccurate debris identification.
1. Position an oil pan under the automatic transmission's inlet and outlet cooler hoses.
2. Clean the exterior and tip of the cooler inlet hose.
3. Insert the extension adapter hose of a can of Transmission
Cooler Cleaner (Nissan P/N 999MP-AM006) into the cooler out-
let hose.
CAUTION:

Wear safety glasses and rubber gloves when spraying
the Transmission Cooler Cleaner.

Spray cooler cleaner only with adequate ventilation.

Avoid contact with eyes and skin.

Do not breath vapors or spray mist.
4. Hold the hose and can as high as possible and spray Transmis- sion Cooler Cleaner in a continuous stream into the cooler outlet
hose until fluid flows out of the cooler inlet hose for 5 seconds.
5. Tie a common white, basket-type coffee filter to the end of the cooler inlet hose.
SCIA3832E
SCIA3831E
SCIA3833E

A/T CONTROL SYSTEMAT-19
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Shift MechanismECS00CDV
The automatic transmission uses compact triple planetary gear systems to improve power-transmission effi-
ciency, simplify construction and reduce weight.
It also employs an optimum shift control and super wide gear ratios. They improve starting performance and
acceleration during medium and high-speed operation.
CONSTRUCTION
FUNCTION OF CLUTCH AND BRAKE
1. Front brake 2. Input clutch3. Direct clutch
4. High and low reverse clutch 5. Reverse brake6. Forward brake
7. Low coast brake 8. 1st one-way clutch9. 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
PCIA0002J
Name of the PartAbbreviation Function
Front brake (1) FR/B Fastens the front sun gear (11).
Input clutch (2) I/CConnects the input shaft (12), the front internal gear (14) and the mid internal
gear (13).
Direct clutch (3) D/C Connects the rear carrier (15) and the rear sun gear (16).
High and low reverse clutch (4) HLR/C Connects the mid sun gear (17) and the rear sun gear (16).
Reverse brake (5) R/B Fastens the rear carrier (15).
Forward brake (6) Fwd/B Fastens the mid sun gear (17).
Low coast brake (7) LC/B Fastens the mid sun gear (17).
1st one-way clutch (8) 1st OWCAllows the rear sun gear (16) to turn freely forward relative to the mid sun gear
(17) but fastens it for reverse rotation.
Forward one-way clutch (9) Fwd OWCAllows the mid sun gear (17) to turn freely in the forward direction but fastens it
for reverse rotation.
3rd one-way clutch (10) 3rd OWCAllows the front sun gear (11) to turn freely in the forward direction but fastens
it for reverse rotation.