engine INFINITI QX56 2007 Factory Owner's Manual

AT-8
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PRECAUTIONS
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000003532218
The Supplemental Restraint System such as “AIR 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 whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inoperative, 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 incorrect removal and installation of the SRS, can lead to personal
injury caused by unintentional activation of the system. For removal of Spiral Cable and Air Bag
Module, see the SRS section.
• Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or har-
ness connectors.
Precaution for On Board Diagnosis (OBD) System of A/T and EngineINFOID:0000000003532219
The ECM has an on board diagnostic system. It will light up the malfunction indicator lamp (MIL) to warn the
driver of a malfunction causing emission deterioration.
CAUTION:
• Be sure to turn the ignition switch “OFF” and disconnect the negative battery cable before any repair
or inspection work. The open/short circuit of related switches, sensors, solenoid valves, etc. Will
cause the MIL to light up.
• Be sure to connect and lock the connectors securely after work. A loose (unlocked) connector will
cause the MIL to light up due to an open circuit. (Be sure the connector is free from water, grease,
dirt, bent terminals, etc.)
• Be sure to route and secure the harnesses properly after work. Interference of the harness with a
bracket, etc. May cause the MIL to light up due to a short circuit.
• Be sure to connect rubber tubes properly after work. A misconnected or disconnected rubber tube
may cause the MIL to light up due to a malfunction of the EGR system or fuel injection system, etc.
• Be sure to erase the unnecessary malfunction information (repairs completed) from the TCM and
ECM before returning the vehicle to the customer.
PrecautionINFOID:0000000003532220
•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”.
SEF289H

A/T FLUID
AT-13
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A/T FLUID
Changing Automatic Transmission Fluid (ATF)INFOID:0000000003532224
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% increase 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 ATF 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-13, "
Checking Automatic Transmission Fluid (ATF)". If the
ATF is still dirty, repeat steps 2 through 5.
Checking Automatic Transmission Fluid (ATF)INFOID:0000000003532225
1. Remove the ATF level gauge bolt.Drain plug : Refer to AT-228, "
Component".
WLIA0014E
ATF type and capacity : Refer to MA-10, "Fluids and Lubricants".
Drain plug : Refer to AT-228, "
Component".
ATF level gauge bolt : Refer to AT-223, "
Removal and Installation (2WD)",
AT-225, "
Removal and Installation (4WD)".

AT-14
< SERVICE INFORMATION >
A/T FLUID
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.
e. Re-insert the ATF level gauge into the charging pipe until the
cap contacts the top of the charging pipe as shown.
CAUTION:
To check 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.
f. Remove the ATF level gauge and note the ATF level. If the ATF
level is at low side of range, add ATF to the transmission
through the charging pipe.
CAUTION:
Do not overfill the transmission with ATF.
g. Install the ATF level gauge and the ATF level gauge bolt.
3. Warm up the engine.
4. Check for any ATF leaks.
5. Drive the vehicle to increase the ATF temperature to 80° C (176° F).
6. Allow the ATF temperature to fall to approximately 65°C (149°F). Use the CONSULT-II to monitor the ATF
temperature as follows:
NOTE:
ATF level will be greatly affected by temperature as shown. Therefore monitor the ATF temperature data
using the CONSULT-II.
a. Connect CONSULT-II to data link connector.
b. Select “MAIN SIGNALS” in “DATA MONITOR” mode for “A/T” with CONSULT-II.
c. Read out the value of “ATF TEMP 1”.
WLIA0014E
ATF level gauge bolt : Refer to AT-223, "Removal and Installation (2WD)",
AT-225, "
Removal and Installation (4WD)".
SCIA1684E
SLIA0016E

A/T CONTROL SYSTEM
AT-23
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Since both the forward brake and the reverse brake are released, torque from the input shaft drive is not trans-
mitted to the output shaft.
“P” Position
• The same as for the “N” position, both the forward brake and the reverse brake are released, so torque from
the input shaft drive is not transmitted to the output shaft.
• The parking pawl linked with the select lever meshes with the parking gear and fastens the output shaft
mechanically.
“D”, “4”, “3”, “2” Positions 1st Gear
• The forward brake and the forward one-way clutch regulate reverse rotation of the mid sun gear.
• The 1st one-way clutch regulates reverse rotation of the rear sun gear.
• The 3rd one-way clutch regulates reverse rotation of the front sun gear.
• During deceleration, the mid sun gear turns forward, so the forward one-way clutch idles and the engine
brake is not activated.
1. Front brake 2. Input clutch 3. 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 gear 12. Input shaft
13. Mid internal gear 14. Front internal gear 15. Rear carrier
16. Rear sun gear 17. Mid sun gear 18. Front carrier
19. Mid carrier 20. Rear internal gear 21. Output shaft
22. Parking gear 23. Parking pawl
PCIA0003J

AT-24
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A/T CONTROL SYSTEM
“1 ” Position 1st Gear
• The front brake fastens the front sun gear.
• The forward brake and the forward one-way clutch regulate reverse rotation of the mid sun gear.
• High and low reverse clutch connects the rear sun gear and the mid sun gear.
• The low coast brake fastens the mid sun gear.
• During deceleration, the low coast brake regulates forward rotation of the mid sun gear and the engine brake
functions.
1. Front brake 2. Input clutch 3. 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 gear 12. Input shaft
13. Mid internal gear 14. Front internal gear 15. Rear carrier
16. Rear sun gear 17. Mid sun gear 18. Front carrier
19. Mid carrier 20. Rear internal gear 21. Output shaft
22. Parking gear 23. Parking pawl
SCIA1512E

A/T CONTROL SYSTEM
AT-25
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P “D”, “4”, “3” Positions 2nd Gear
• The forward brake and the forward one-way clutch regulate reverse rotation of the mid sun gear.
• The 3rd one-way clutch regulates reverse rotation of the front sun gear.
• The direct clutch is coupled and the rear carrier and rear sun gear are connected.
• During deceleration, the mid sun gear turns forward, so the forward one-way clutch idles and engine brake is
not activated.
1. Front brake 2. Input clutch 3. 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 gear 12. Input shaft
13. Mid internal gear 14. Front internal gear 15. Rear carrier
16. Rear sun gear 17. Mid sun gear 18. Front carrier
19. Mid carrier 20. Rear internal gear 21. Output shaft
22. Parking gear 23. Parking pawl
SCIA1513E

AT-26
< SERVICE INFORMATION >
A/T CONTROL SYSTEM
“2”, “1” Positions 2nd Gear
• The front brake fastens the front sun gear.
• The forward brake and the forward one-way clutch regulate reverse rotation of the mid sun gear.
• The direct clutch is coupled, and the rear carrier and rear sun gear are connected.
• The low coast brake fastens the mid sun gear.
• During deceleration, the low coast brake regulates forward rotation of the mid sun gear and the engine brake
functions.
1. Front brake 2. Input clutch 3. 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 gear 12. Input shaft
13. Mid internal gear 14. Front internal gear 15. Rear carrier
16. Rear sun gear 17. Mid sun gear 18. Front carrier
19. Mid carrier 20. Rear internal gear 21. Output shaft
22. Parking gear 23. Parking pawl
SCIA1514E

A/T CONTROL SYSTEM
AT-31
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TCM FunctionINFOID:0000000003532230
The function of the TCM is to:
• Receive input signals sent from various switches and sensors.
• Determine required line pressure, shifting point, 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 various sensors or signals. It always
controls the optimum shift position and reduces shifting and lock-up shocks.
1. Front brake 2. Input clutch 3. 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 gear 12. Input shaft
13. Mid internal gear 14. Front internal gear 15. Rear carrier
16. Rear sun gear 17. Mid sun gear 18. Front carrier
19. Mid carrier 20. Rear internal gear 21. Output shaft
22. Parking gear 23. Parking pawl
SCIA1519E

AT-32
< SERVICE INFORMATION >
A/T CONTROL SYSTEM
CONTROL SYSTEM DIAGRAM
CAN CommunicationINFOID:0000000003532231
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,
"CAN Communication System".
SENSORS (or SIGNALS)
⇒TCM
⇒ACTUATORS
PNP switch
Accelerator pedal position sensor
Closed throttle position signal
Wide open throttle position signal
Engine speed signal
A/T fluid temperature sensor
Revolution sensor
Vehicle speed signal
Stop lamp switch signal
Turbine revolution sensor
1st position switch signal
4th position switch signal
ATF pressure switch signal
Tow mode switch signalShift control
Line pressure control
Lock-up control
Engine brake control
Timing control
Fail-safe control
Self-diagnosis
CONSULT-II communication line
Duet-EA control
CAN systemInput 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
SCIA5624E

A/T CONTROL SYSTEM
AT-33
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Input/Output Signal of TCMINFOID:0000000003532232
*1: Spare for vehicle speed sensor·A/T (revolution sensor)
*2: Spare for accelerator pedal position signal
*3: If these input and output signals are different, the TCM triggers the fail-safe function.
*4: CAN communications
Line Pressure ControlINFOID:0000000003532233
• When an input torque signal equivalent to the engine drive force is sent from the ECM to the TCM, the TCM
controls the line pressure solenoid.
Control itemLine
pressure
controlVehicle
speed
controlShift
controlLock-up
controlEngine
brake
controlFail-safe
function
(*3)Self-diag-
nostics
function
InputAccelerator pedal position signal
(*4)XXXXXXX
Vehicle speed sensor A/T
(revolution sensor)XXXX XX
Vehicle speed sensor MTR
(*1) (*4)XXXX X
Closed throttle position signal
(*4)(*2) X (*2) X X (*2) X X
Wide open throttle position signal
(*4)(*2) X (*2) X (*2) X X
Turbine revolution sensor 1 X X X X X
Turbine revolution sensor 2
(for 4th speed only)XXXXX
Engine speed signals
(*4)XX
PNP switch XXXXXXX
A/T fluid temperature sensors 1, 2 X X X X X X X
ASCDOperation signal
(*4)XXXX
Overdrive cancel sig-
nal
(*4)XXX
TCM power supply voltage signal X X X X X X
Out-
putDirect clutch solenoid (ATF pressure
switch 5)XX XX
Input clutch solenoid (ATF pressure
switch 3)XX XX
High and low reverse clutch sole-
noid (ATF pressure switch 6)XX XX
Front brake solenoid (ATF pressure
switch 1)XX XX
Low coast brake solenoid (ATF
pressure switch 2)XX XXX
Line pressure solenoid X X X X X X X
TCC solenoid X X X
Starter relayXX