2011 INFINITI QX56 Fuel

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

SYSTEMTM-53
< SYSTEM DESCRIPTION > [7AT: RE7R01B]
C
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M A
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TM
N
O P
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

SYSTEMTM-57
< SYSTEM DESCRIPTION > [7AT: RE7R01B]
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O PLock-up Operation Condition Table
Lock-up released
 In the lock-up released state, the torque converter clutch control valve is set into the unlocked state by the
torque converter clutch solenoid and the lock-up apply pressure is drained.
in this way, the torque converter clutch piston is not coupled.
Lock-up Applied
 In the lock-up applied state, the torque converter clutch control valve is set into the locked state by the
torque converter clutch solenoid and lock-up apply pressure is generated.
In this way, the torque converter clutch piston is pressed and coupled.
Smooth Lock-up Control
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 this 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 steadily 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 states, the torque conv erter clutch piston 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 fo r 2GR, 3GR, 4GR, 5GR, 6GR and 7GR.
A/T SHIFT LOCK SYSTEM
JSDIA0847GB
Selector lever “D” position “M” position
Gear position 765432765432
Lock-up×––––– ××××××
Slip lock-up ××××××××××××
Revision: 2010 May2011 QX56

TM-116
< DTC/CIRCUIT DIAGNOSIS >[7AT: RE7R01B]
P0730 INCORRECT GEAR RATIO
P0730 INCORRECT GEAR RATIO
DescriptionINFOID:0000000006226818
 TCM detects a high-rpm state of the under drive sun gear.
 The number of revolutions of the under drive sun gear
is calculated with the input speed sensor 1 and 2.
DTC LogicINFOID:0000000006226819
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
CAUTION:
“TM-116, "
Diagnosis Procedure"” must be performed before starting “DTC CONFIRMATION PROCE-
DURE”.
 Never perform “DTC CONFIRMATION PROCEDURE” before completing the repair, which may cause secondary malfunction.
 Always drive vehicle at a safe speed.
1.PRECONDITIONING
If “DTC CONFIRMATION PROCEDURE” is previously c onducted, always turn ignition switch OFF and wait at
least 10 seconds before performing the next test.
>> GO TO 2.
2.CHECK DTC DETECTION
With CONSULT-III
1. Start the engine.
2. Select “Self Diagnostic Results” in “ENGINE”.
3. Drive vehicle under the similar conditions to (1st trip) Freeze Frame Data for 10 minutes. Refer to the
table below.
Hold the accelerator pedal as steady as possible.
With GST
Follow the procedure “With CONSULT-III”.
Is
“P0730” detected?
YES >> Go to TM-116, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006226820
1.DETECT MALFUNCTIONING ITEM
Disassemble the A/T assembly to check component parts. Refer to TM-211, "
Exploded View".
NOTE:
Check the component parts, referring to “Possible cause” in “DTC DETECTION LOGIC”. Refer to TM-116,
"DTC Logic".
Is the inspection result normal?
DTC Trouble diagnosis name DTC is detected if... Possible cause
P0730 Incorrect Gear Ratio The revolution of under drive
sun gear is 8,000 rpm or more.
NOTE:
Not detected when in “P” or “N”
position and during a shift to “P”
or “N” position. 2346 brake solenoid valve
 Front brake solenoid valve
 Input speed sensor 2
ENGINE SPEED Same value as
the Freeze Frame Data.
VEHICLE SPEED Same value as the Freeze Frame Data.
B/FUEL SCHDL Same value as the Freeze Frame Data.
Revision: 2010 May2011 QX56

WCS-14
< SYSTEM DESCRIPTION >
DIAGNOSIS SYSTEM (COMBINATION METER)
DIAGNOSIS SYSTEM (COMBINATION METER)
CONSULT-III FunctionINFOID:0000000006222742
CONSULT-III APPLICATION ITEMS
CONSULT-III can perform the following diagnosis modes via CAN communication and the combination meter.
SELF DIAG RESULT
Refer to MWI-43, "DTC Index".
DATA MONITOR
Display Item List
X: Applicable
System Diagnosis mode Description
METER/M&A Self Diagnostic Result The combination meter checks the conditions and displays memorized errors.
Data Monitor Displays the combination meter input/output data in real time.
Special function Lighting history of the warning lamp and indicator lamp can be checked.
Display item [Unit]
MAIN
SIGNALS Description
SPEED METER
[km/h] XValue of vehicle speed
signal received from ABS actuator and el ectric unit (control
unit) via CAN communication.
NOTE:
655.35 is displayed when the malfunction signal is received.
SPEED OUTPUT
[km/h] XVehicle speed signal value transmitted to other units via CAN communication.
NOTE:
655.35 is displayed when the malfunction signal is received.
ODO OUTPUT
[km/h or mph] Odometer signal value transmitted to other units via CAN communication.
TACHO METER
[rpm] XValue of the engine speed signal received from ECM via CAN communication.
NOTE:
8191.875 is displayed when the malfunction signal is received.
FUEL METER
[L] X Fuel level indicated on combination meter.
W TEMP METER
[ ° C] XValue of engine coolant temperature signal is received from ECM via CAN com-
munication.
NOTE:
215 is displayed when the malfunction signal is input.
ABS W/L
[On/Off] Status of ABS warning lamp
detected from ABS warning lamp signal is received
from ABS actuator and electric unit (control unit) via CAN communication.
VDC/TCS IND
[On/Off] Status of VDC OFF indicator lamp detected from VDC OFF indicator lamp signal
is received from ABS actuator and electric
unit (control unit) via CAN communica-
tion.
SLIP IND
[On/Off] Status of VDC warning lamp detected from VDC warning lamp signal received
from ABS actuator and electric unit (control unit) via CAN communication.
BRAKE W/L
[On/Off] Status of brake warning lamp detected from brake warning lamp signal is received
from ABS actuator and electric unit (control unit) via CAN communication.
NOTE:
Displays “Off” if the brake warning lamp is illuminated when the valve check starts,
the parking brake switch is turned ON or the brake fluid level switch is turned ON.
DOOR W/L
[On/Off] Status of door open warning detected from door switch signal received from BCM
via CAN communication.
HI-BEAM IND
[On/Off] Status of high beam indicator lamp detected from high beam request signal is re-
ceived from BCM via CAN communication.
TURN IND
[On/Off] Status of turn indicator lamp detected from turn indicator signal is received from
BCM via CAN communication.
Revision: 2010 May2011 QX56

WCS
DIAGNOSIS SYSTEM (COMBINATION METER)
WCS-15
< SYSTEM DESCRIPTION >
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FR FOG IND
[Off] This item is displayed, but cannot be monitored.
RR FOG IND
[Off] This item is displayed, but cannot be monitored.
LIGHT IND
[On/Off] Status of light indicator lamp detected from position light request signal is received
from BCM via CAN communication.
OIL W/L
[On/Off] Status of oil pressure warning lamp detected from oil pressure switch signal is re-
ceived from BCM via CAN communication.
MIL
[On/Off] Status of malfunction indicator lamp detected from malfunctioning indicator lamp
signal is received from ECM via CAN communication.
GLOW IND
[Off] This item is displayed, but cannot be monitored.
CRUISE IND
[On/Off]  Status of CRUISE indicator detected from ASCD status signal is received from
ECM via CAN communicat ion. (ASCD models)
 Status of CRUISE indicator de tected from meter display signal is received from
ADAS control unit via CAN communication. (ICC models)
SET IND
[On/Off] Status of SET indicator detected from meter display signal is received from ADAS
control unit via CAN communication.
CRUISE W/L
[On/Off] Status of CRUISE warning lamp
judged from ICC warning lamp signal received
from ADAS control unit with CAN communication line.
BA W/L
[On/Off] Status of IBA OFF indicator lamp judged from IBA OFF indicator lamp signal re-
ceived from ADAS control unit with CAN communication line.
ATC/T-AMT W/L
[On/Off] Status of A/T CHECK warning lamp judged
from A/T CHECK indicator lamp signal
received from TCM with CAN communication line.
ATF TEMP W/L
[Off] This item is displayed, but cannot be monitored.
4WD W/L
[On/Off] Status of 4WD warning lamp judged from 4WD warning lamp signal received from
4WD control unit with
CAN communication line.
FUEL W/L
[On/Off] Low-fuel warning lamp status detected by the identified fuel level.
WASHER W/L
[On/Off] Status of low washer fluid warning judged from washer level switch input to com-
bination meter.
AIR PRES W/L
[On/Off] Status of low tire pressure warning lamp judged from low tire pressure warning
lamp signal received from BCM with CAN communication line.
KEY G/Y W/L
[On/Off] Status of KEY warning lamp
(Green/Yellow) detected from KEY warning lamp sig-
nal is received from BCM via CAN communication.
KEY KNOB W/L
[Off] This item is displayed, but cannot be monitored.
AFS OFF IND
[On/Off] Status of AFS OFF indicator lamp judged from AFS OFF indicator lamp signal re-
ceived from AFS control unit with CAN communication line.
DDS
* W/L
[Off] This item is displayed, but cannot be monitored.
LANE W/L
[On/Off] Status of lane departure warning lamp judged from lane departure warning lamp
signal received from ADAS control unit with CAN communication line.
LDP IND
[On/Off] Status of LDP ON indicator lamp judged from LDP ON indicator lamp signal re-
ceived from ADAS control unit with CAN communication line.
AT P W / L
[On/Off] Status of ATP warning lamp judged from ATP warning lamp signal received from
4WD control unit with
CAN communication line.
DCA IND
[Off] This item is displayed, but cannot be monitored.
CHECK SUS IND
[On/Off] Status of CK SUSP indicator lamp judged from CK SUSP indicator lamp signal re-
ceived from E-SUS control unit with CAN communication line.
Display item [Unit]
MAIN
SIGNALS Description
Revision: 2010 May2011 QX56

WCS
DIAGNOSIS SYSTEM (COMBINATION METER)
WCS-17
< SYSTEM DESCRIPTION >
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*: DDS (hill descent control) NOTE:
Some items are not available according to vehicle specification.
SPECIAL FUNCTION
Special menu
W/L ON HISTORY
 Stores histories when warning/indicator lamp is turned on.
 “W/L ON HISTORY” indicates the “TIME” when the warning/ indicator lamp is turned on.
 The “TIME” above is:
- 0: The condition that the warning/indicator lamp has been turned on 1 or more times after starting the engine and waiting for 30 seconds.
- 1 - 39: The number of times the engine was restarted after the 0 condition.
- NO W/L ON HISTORY: Stores NO (0) turning on history of warning/indicator lamp.
NOTE:
 W/L ON HISTORY is not stored for approximately 30 seconds after the engine starts.
 Brake warning lamp does not store any history when the parking brake is applied or the brake fluid level gets
low.
Display Item
FUEL LOW SIG
[On/Off] Status of fuel level low warning signal to output to AV control unit via CAN com-
munication.
TOW MODE IND
[On/Off] Status of TOW mode indicator lamp judged from TOW mode indicator lamp signal
received from TCM with CAN communication line.
BUZZER
[On/Off] XBuzzer status (in the combination meter) is detected from the buzzer output signal
received from each unit via CAN communication and the warning output condition
of the combination meter.
Display item [Unit]
MAIN
SIGNALS Description
Display item Description
W/L ON HISTORY Lighting history of warning lamp and indicator lamp can be checked.
Display item Description
ABS W/L Lighting history of ABS warning lamp.
VDC/TCS IND Lighting history of VDC OFF indicator lamp.
SLIP IND Lighting history of VDC warning lamp.
BRAKE W/L Lighting history of brake warning lamp.
DOOR W/L Lighting history of door open warning.
TRUNK/GLAS-H This item is displayed, but cannot be monitored.
OIL W/L Lighting history of oil pressure warning lamp.
C-ENG W/L Lighting history of malfunction indicator lamp.
C-ENG2 W/L This item is displayed, but cannot be monitored.
CRUISE IND Lighting history of CRUISE indicator lamp.
SET IND Lighting history of SET indicator lamp.
CRUISE W/L Lighting histor y of CRUISE warning lamp.
BA W/L Lighting history of IBA OFF indicator lamp.
O/D OFF IND This item is displayed, but cannot be monitored.
ATC/T-AMT W/L Lighting history of A/T CHECK warning lamp.
ATF TEMP W/L This item is displayed, but cannot be monitored.
CVT IND This item is displayed, but cannot be monitored.
SPORT IND This item is displayed, but cannot be monitored.
Revision: 2010 May2011 QX56

WCS-18
< SYSTEM DESCRIPTION >
DIAGNOSIS SYSTEM (COMBINATION METER)
4WD W/L Lighting history of 4WD warning lamp.
FUEL W/L Lighting history of low fuel level warning.
WASHER W/L Lighting history of low washer fluid warning.
AIR PRES W/L Lighting history of low tire pressure warning lamp.
KEY G/Y W/L Lighting history of KEY warning lamp.
KEY R W/L This item is displayed, but cannot be monitored.
KEY KNOB W/L This item is displa yed, but cannot be monitored.
EPS W/L This item is displayed, but cannot be monitored.
e-4WD This item is displayed, but cannot be monitored.
AFS OFF IND This item is displayed, but cannot be monitored.
4WAS/RAS W/L This item is displayed, but cannot be monitored.
HDC W/L This item is displayed, but cannot be monitored.
SYS FAIL W/L This item is displa yed, but cannot be monitored.
SFT POSI W/L This item is displayed, but cannot be monitored.
HV BAT W/L This item is displayed, but cannot be monitored.
HEV BRAKE W/L This item is displayed, but cannot be monitored.
SFT OPER W/L This item is displayed, but cannot be monitored.
LANE W/L Lighting history of lane departure warning lamp.
CHAGE W/L This item is displayed, but cannot be monitored.
OIL LEV LOW This item is displayed, but cannot be monitored.
DPF W/L This item is displayed, but cannot be monitored.
TRAILER IND This item is displayed, but cannot be monitored.
RUN FLAT W/L This item is displa yed, but cannot be monitored.
E-SUS W/L This item is displayed, but cannot be monitored.
LAUNCH CNT W/L This item is displayed, but cannot be monitored.
BRAKE PAD W/L This item is displa yed, but cannot be monitored.
Display item Description
Revision: 2010 May2011 QX56