2011 INFINITI QX56 transmission fluid

TM-42
< SYSTEM DESCRIPTION >[7AT: RE7R01B]
STRUCTURE AND OPERATION
A/T FLUID COOLER SCHEMATIC
COMPONENT DESCRIPTION
A/T fluid warmer
 The A/T fluid warmer (1) is installed on the front part of cylinder
block of engine.
 When engine is started while engine and A/T are cold, engine cool-
ant temperature rises more quickly than A/T fluid temperature. A/T
fluid warmer is provided with two circuits for ATF and engine cool-
ant respectively so that warmed engine coolant warms ATF
quickly. This helps shorten A/T warming up time, improving fuel
economy.
 A cooling effect is obtained when A/T fluid temperature is high.
A/T fluid cooler (with bypass valve)
 A/T fluid cooler (1) is installed in the front of radiator (2) and con- denser (3).
 A/T fluid cooler is provided with a bypass valve that controls ATF
flow. Bypass valve operates by thermo wax and a return spring.
Bypass valve fully opens when A/T fluid temperature is approxi-
mately 90 °C (194 °F) and fully closes when A/T fluid temperature is
approximately 100 °C (212 °F).
 When A/T fluid temperature is low, the bypass valve is open. Most of ATF therefore returns to the transmission without flowing into the
cooler core that has larger flow resistance.
JSDIA1803GB
JSDIA1811ZZ
JSDIA1814ZZ
JSDIA1815GB
Revision: 2010 May2011 QX56

STRUCTURE AND OPERATIONTM-43
< SYSTEM DESCRIPTION > [7AT: RE7R01B]
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 When A/T fluid temperature rises [to approximately 100 °C
(212 °F)], bypass valve closes and allows ATF to flow into cooler
core. ATF flowing into cooler core is cooled by air stream caused
by vehicle travel and returned to transmission.
JSDIA1816GB
Revision: 2010 May2011 QX56

TM-44
< SYSTEM DESCRIPTION >[7AT: RE7R01B]
SYSTEM
SYSTEM
A/T CONTROL SYSTEM
A/T CONTROL SYSTEM : System DiagramINFOID:0000000006226767
A/T CONTROL SYSTEM : System DescriptionINFOID:0000000006226768
INPUT/OUTPUT SIGNAL CHART
SYSTEM DESCRIPTION
 The A/T senses vehicle operating conditions through vari
ous sensors or signals. It always controls the opti-
mum shift position and reduces shifting and lock-up shocks.
 Receive input signals transmitted from various switches and sensors.
 Determine required line pressure, shifting point, lock-up operation, etc.
JSDIA1853GB
Sensor (or signal)
⇒TCM function
⇒Actuator
Transmission range switch
Accelerator pedal position signal
Closed throttle position signal
Wide open throttle position signal
Engine speed signal
A/T fluid temperature sensor
Output speed sensor
Vehicle speed signal
Manual mode switch signal
Stop lamp switch signal
Input speed sensor 1, 2
Yaw rate/side/decel G sensor
Tow mode switch signal Line pressure control (
TM-48
)
Shift change control ( TM-50
)
Shift pattern control ( TM-54
)
Lock-up control ( TM-56
)
Fail-safe control ( TM-45
)
Self-diagnosis ( TM-61
)
CONSULT-III communication line ( TM-61
)
CAN communication line ( TM-103
)Input clutch solenoid valve
Direct clutch solenoid valve
Front brake solenoid valve
High and low reverse clutch solenoid valve
Low brake solenoid valve
Torque converter clutch solenoid valve
Line pressure solenoid valve
Anti-interlock solenoid valve
2346 brake solenoid valve
A/T CHECK indicator lamp
Tow mode indicator lamp
Shift position indicator
Back-up lamp relay
Starter relay
Revision: 2010 May2011 QX56

SYSTEMTM-53
< SYSTEM DESCRIPTION > [7AT: RE7R01B]
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Input/Output Signal Chart
*: This signal is transmitted via communication line.
The TCM activates low brake solenoid valve and controls t he low brake oil pressure to the low pressure level
if the driver does not intend to start the vehicle while the vehicle is being stopped in the “D” position. Therefore,
the low brake is in the release (slip) status and the pow er transmission route of A/T is the same status as the
“N” position. This can decrease the engine load and im proves the fuel economy because the drive force of
engine is not transmitted to the output shaft of A/T.
Idle Neutral Contro l Start Condition
Idle neutral control starts when all of the following c onditions are satisfied. However, the control ends when
any one of the following conditions becomes insufficient during idle neutral control.
NOTE:
The idle neutral control is terminated or prohibited when the TCM and ECM detect that the vehicle is in any of
the conditions as per the following.
 Engine cooling water temperature and A/T fluid temperature are below or above a prescribed temperature.
 A/T malfunction occurs.
 DTC is detected.
 Fail-safe mode activates.
 Idle neutral control is performed continuously for a certain period of time.
Idle Neutral Contro l Resume Condition
Idle neutral control can be resumed when its start condition is fulfilled after any of the following operations is
performed (unless a malfunction occurs in the vehicle).
 After driving at more than a prescribed speed.
 When idle neutral control start conditions are fulfilled for a certain period of time.
SHIFT PATTERN CONTROL
Item Signal
TCM function Actuator
Each sensor, switch and
control unit ⇒ TCM TCM
⇒ ECM ECM ⇒ TCM
Input speed sensor 1, 2 Input speed
N idle instruction
signal (Standby sig- nal)* N idle instruction
signal (Start signal)* Idle neutral con-
trol Low brake sole-
noid valve
Output speed sensor Output shaft revolution
A/T fluid temperature
sensor
ATF temperature
Transmission range
switch Selector lever position
ECM Engine speed signal*
Accelerator pedal posi-
tion signal*
Throttle position signal*
BCM Stop lamp switch signal*
Turn indicator signal*
ABS actuator electric
unit (control unit) Pressure sensor signal*
Decel G sensor signal*
Combination meter Vehicle speed signal*
Driving location : Level road and gentle slope
Selector lever position : “D” position
Vehicle speed : 0 km/h (0 MPH)
Accelerator pedal opening : 0.0 / 8
Brake pedal : Depress
Engine speed : Idle speed
Snow mode switch : OFF
Turn signal lamp and ha zard warning lamp : OFF
Revision: 2010 May2011 QX56

TM-56
< SYSTEM DESCRIPTION >[7AT: RE7R01B]
SYSTEM
Input/Output Signal Chart
*: This signal is transmitted via CAN communication line.
 The TCM receives the manual mode signal, non-manual mode signal, manual mode shift up signal and
manual mode shift down signal from combination meter via CAN communication line. The TCM shifts shift
pattern control to the manual mode based on these signal s, and then shifts the A/T by operating each sole-
noid valve according to the shift operation of the driver.
 The TCM prohibits the manual mode while being in fail-safe mode due to an A/T malfunction, etc. Refer to TM-74, "
Fail-Safe".
Manual Mode Information
 The TCM transmits the manual mode shift refusal signal to the combination meter if the TCM refuses the
transmission from the driving status of vehicle when the selector lever shifts to “UP (+ side)” or “DOWN (−
side)” side. The combination meter blinks shift indicator on the combination meter and sounds the buzzer to
indicate the driver that the shifting is not performed when receiving this signal. However, the TCM does not
transmit the manual mode shift refusal signal in the conditions as per the following.
- When the selector lever shifts to “DOWN ( − side)” side in 1GR.
- When the selector lever shifts to “UP (+ side)” side in 7GR.
LOCK-UP CONTROL
LOCK-UP CONTROL : System DiagramINFOID:0000000006226777
LOCK-UP CONTROL : System DescriptionINFOID:0000000006226778
 The torque converter clutch piston in the torque conv erter is engaged to eliminate torque converter slip to
increase power transmission efficiency.
 Lock-up operation, however, is prohibited when A/T fluid temperature is too low.
 The torque converter clutch control valve operation is controlled by the torque converter clutch solenoid
valve, which is controlled by a signal from TCM, and the torque converter clutch control valve engages or
releases the torque converter clutch piston.
Item Signal TCM function Actuator
Output speed sensor Vehicle speed
Manual mode High and low reverse clutch
solenoid valve
 Direct clutch solenoid valve
 Input clutch solenoid valve
 Low brake solenoid valve
 2346 brake solenoid valve
 Front brake solenoid valve
 Torque converter clutch sole- noid valve
 Line pressure solenoid valve
 Anti-interlock solenoid valve
A/T fluid temperature sensor ATF temperature
ECM
Engine speed signal*
Accelerator pedal position sig-
nal*
Combination meter Manual mode signal*
Non-manual mode signal*
Manual mode shift up signal*
Manual mode shift down signal*
JSDIA1350GB
Revision: 2010 May2011 QX56

TM-78
< ECU DIAGNOSIS INFORMATION >[7AT: RE7R01B]
TCM
DTC Index
INFOID:0000000006226786
NOTE:
 If some DTCs are displayed at the same time, per form inspections one by one based on the priority as per
the following list. Refer to TM-77, "
DTC Inspection Priority Chart".
 The IGN counter is indicated in Freeze frame data (FFD). Refer to TM-61, "
CONSULT-III Function (TRANS-
MISSION)".
2P0615 STARTER RELAY
TM-104, "
DTC Logic"
P0705 T/M RANGE SWITCH ATM-106, "DTC Logic"
P0710 FLUID TEMP SENSOR ATM-107, "DTC Logic"
P0717 INPUT SPEED SENSOR ATM-109, "DTC Logic"
P0720 OUTPUT SPEED SENSOR TM-110, "DTC Logic"
P0740 TORQUE CONVERTERTM-128, "DTC Logic"
P0745 PC SOLENOID ATM-131, "DTC Logic"
P0750 SHIFT SOLENOID ATM-132, "DTC Logic"
P0775 PC SOLENOID BTM-133, "DTC Logic"
P0795 PC SOLENOID CTM-136, "DTC Logic"
P2713 PC SOLENOID DTM-147, "DTC Logic"
P2722 PC SOLENOID ETM-148, "DTC Logic"
P2731 PC SOLENOID FTM-149, "DTC Logic"
P2807 PC SOLENOID GTM-150, "DTC Logic"
3P0729 6GR INCORRECT RATIO
TM-114, "
DTC Logic"
P0730 INCORRECT GR RATIOTM-116, "DTC Logic"
P0731 1GR INCORRECT RATIOTM-118, "DTC Logic"
P0732 2GR INCORRECT RATIOTM-120, "DTC Logic"
P0733 3GR INCORRECT RATIOTM-122, "DTC Logic"
P0734 4GR INCORRECT RATIOTM-124, "DTC Logic"
P0735 5GR INCORRECT RATIOTM-126, "DTC Logic"
P0744 TORQUE CONVERTERTM-129, "DTC Logic"
P0780 SHIFTTM-134, "DTC Logic"
P1730 INTERLOCKTM-140, "DTC Logic"
P1734 7GR INCORRECT RATIOTM-142, "DTC Logic"
4U0300 CAN COMM DATA
TM-102, "
DTC Logic"
P0725 ENGINE SPEED TM-112, "DTC Logic"
P1705 TP SENSORTM-137, "DTC Logic"
P1721 VEHICLE SPEED SIGNALTM-138, "DTC Logic"
P1815 M-MODE SWITCHTM-144, "DTC Logic"
Priority Detected items (DTC) Reference
DTC*1
Items
(CONSULT-III screen terms) Reference
MIL*2, “ENGINE” with
CONSULT-III or GST CONSULT-III only
“TRANSMISSION”
— P0615 STARTER RELAY TM-104
P0705 P0705 T/M RANGE SWITCH A TM-106
P0710 P0710 FLUID TEMP SENSOR ATM-107
P0717 P0717 INPUT SPEED SENSOR ATM-109
P0720 P0720 OUTPUT SPEED SENSOR TM-110
Revision: 2010 May2011 QX56

TM-96
< BASIC INSPECTION >[7AT: RE7R01B]
A/T FLUID
1. Install the O-ring (315268E000) (A) to the charging pipe
(310811EA5A) (B).
2. Start the engine.
3. Make the ATF temperature approximately 40 °C (104 °F).
NOTE:
The ATF level is greatly affected by the temperature. Always
check the ATF temperature on “ATF TEMP 1” of “Data Monitor”
using CONSULT-III.
4. Park vehicle on level surface and set parking brake.
5. Shift the selector lever through each gear position. Leave selec- tor lever in “P” position.
6. Lift up the vehicle.
7. Check the ATF leakage from transmission.
8. Remove overflow plug from oil pan.
9. Install the charging pipe (A) to the overflow plug hole. CAUTION:
Tighten the charging pipe by hand.
10. Install the bucket pump hose (B) to the charging pipe. CAUTION:
Insert the bucket pump hose all the way to the end of the
charging pipe.
11. Fill approximately 0.5 liters (1/2 US qt, 1/2 lmp qt) of the ATF.
12. Check that the ATF leaks when removing the charging pipe and the bucket pump hose. If the A TF does not leak, refill the ATF.
CAUTION:
Perform “Step 12” with the engine at idle.
13. When the ATF starts to drip, tighten the overflow pl ug to the oil pan to the specified torque. Refer to TM-
182, "Exploded View".
CAUTION:
Never reuse overflow plug.
JSDIA1334ZZ
JSDIA1335ZZ
Revision: 2010 May2011 QX56

A/T FLUID COOLERTM-97
< BASIC INSPECTION > [7AT: RE7R01B]
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A/T FLUID COOLER
CleaningINFOID:0000000006233276
Whenever an A/T is replaced, the A/ T fluid cooler mounted in the radiator must be inspected and cleaned.
Metal debris and friction material, if present, can becom e trapped in the A/T fluid cooler. This debris can con-
taminate the newly serviced A/T or, in severe cases, can bl ock or restrict the flow of ATF. In either case, mal-
function of the newly se rviced A/T may result.
Debris, if present, may build up as ATF 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.
CLEANING PROCEDURE
1. Position an oil pan under the A/T inlet and outlet cooler hoses.
2. Identify the inlet and outlet fluid cooler hoses.
3. Disconnect the A/T fluid cooler inlet and outlet rubber hoses
from the steel cooler tubes or by-pass valve.
NOTE:
Replace the cooler hoses if rubber material from the hose
remains on the tube fitting.
4. Allow any ATF 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 theTransmission Cooler Cleaner.
 Spray Transmission Cooler Cleaner only with adequate
ventilation.
 Avoid contact with eyes and skin.
 Never breath vapors or spray mist.
6. 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 ATF 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 to 9 kg/cm
2 (71 to 128 psi)
through the cooler outlet hose for 10 seconds to force out any
remaining ATF.
10. Repeat steps 5 through 9 three additional times.
11. Position an oil pan under the banjo bolts that connect the A/T fluid cooler steel lines to the A/T.
12. Remove the banjo bolts.
13. Flush each steel line from the cooler side back toward the A/T by spraying Transmission Cooler Cleaner in a continuous stream for 5 seconds.
14. Blow compressed air regulated to 5 to 9 kg/cm
2 (71 to 128 psi) through each steel line from the cooler
side back toward the A/T for 10 seconds to force out any remaining ATF.
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 “DIAGNOSIS PROCEDURE”.
JPDIA0711GB
JPDIA0712GB
JPDIA0713GB
Revision: 2010 May2011 QX56