2007 INFINITI QX56 diagram

AT-4
DTC Confirmation Procedure ................................152
Diagnosis Procedure .............................................152
DTC P1845 ATF PRESSURE SWITCH 5 ........154
Description .............................................................154
CONSULT-II Reference Value in Data Monitor
Mode ......................................................................
154
On Board Diagnosis Logic .....................................154
Possible Cause ......................................................154
DTC Confirmation Procedure ................................154
Diagnosis Procedure .............................................154
DTC P1846 ATF PRESSURE SWITCH 6 ........156
Description .............................................................156
CONSULT-II Reference Value in Data Monitor
Mode ......................................................................
156
On Board Diagnosis Logic .....................................156
Possible Cause ......................................................156
DTC Confirmation Procedure ................................156
Diagnosis Procedure .............................................156
MAIN POWER SUPPLY AND GROUND CIR-
CUIT .................................................................
158
Wiring Diagram - AT - MAIN ..................................158
Diagnosis Procedure .............................................159
CLOSED THROTTLE POSITION AND WIDE
OPEN THROTTLE POSITION CIRCUIT .........
161
CONSULT-II Reference Value in Data Monitor
Mode ......................................................................
161
Diagnosis Procedure .............................................161
BRAKE SIGNAL CIRCUIT ..............................162
CONSULT-II Reference Value in Data Monitor
Mode ......................................................................
162
Diagnosis Procedure .............................................162
TOW MODE SWITCH ......................................163
Description .............................................................163
Wiring Diagram - AT - TMSW ................................163
Diagnosis Procedure .............................................164
TROUBLE DIAGNOSIS FOR SYMPTOMS .....165
Wiring Diagram - AT - NONDTC ............................165
A/T Check Indicator Lamp Does Not Come On .....167
Engine Cannot Be Started in "P" or "N" Position ...168
In "P" Position, Vehicle Moves When Pushed .......168
In "N" Position, Vehicle Moves ..............................169
Large Shock ("N" to "D" Position) ..........................170
Vehicle Does Not Creep Backward in "R" Position ..172
Vehicle Does Not Creep Forward in "D" Position ..175
Vehicle Cannot Be Started from D1 .......................177
A/T Does Not Shift: D1→ D2 ..................................179
A/T Does Not Shift: D2→ D3 ..................................181
A/T Does Not Shift: D3→ D4 ..................................183
A/T Does Not Shift: D4→ D5 ..................................185
A/T Does Not Perform Lock-up .............................187
A/T Does Not Hold Lock-up Condition ...................189
Lock-up Is Not Released .......................................190
Engine Speed Does Not Return to Idle .................191
A/T Does Not Shift: 5th gear → 4th gear ..............192
A/T Does Not Shift: 4th gear → 3rd gear ..............194
A/T Does Not Shift: 3rd gear → 2nd gear .............196
A/T Does Not Shift: 2nd gear → 1st gear .............197
Vehicle Does Not Decelerate By Engine Brake ....199
A/T SHIFT LOCK SYSTEM ..............................202
Description ............................................................202
Shift Lock System Electrical Parts Location ..........202
Wiring Diagram - AT - SHIFT ................................203
Shift Lock Control Unit Reference Value ..............204
Component Inspection ..........................................204
SHIFT CONTROL SYSTEM .............................207
Control Device Removal and Installation ..............207
Adjustment of A/T Position ....................................208
Checking of A/T Position .......................................208
ON-VEHICLE SERVICE ...................................209
Oil Pan ..................................................................209
Control Valve with TCM and A/T Fluid Tempera-
ture Sensor 2 ........................................................
210
Rear Oil Seal .........................................................219
AIR BREATHER HOSE ....................................221
Removal and Installation .......................................221
TRANSMISSION ASSEMBLY ..........................223
Removal and Installation (2WD) ...........................223
Removal and Installation (4WD) ...........................225
OVERHAUL ......................................................228
Component ...........................................................228
Oil Channel ...........................................................235
Location of Adjusting Shims, Needle Bearings,
Thrust Washers and Snap Rings ..........................
237
DISASSEMBLY ................................................240
Disassembly ..........................................................240
REPAIR FOR COMPONENT PARTS ..............258
Oil Pump ...............................................................258
Front Sun Gear, 3rd One-Way Clutch ...................260
Front Carrier, Input Clutch, Rear Internal Gear .....262
Mid Sun Gear, Rear Sun Gear, High and Low Re-
verse Clutch Hub ..................................................
267
High and Low Reverse Clutch ..............................272
Direct Clutch .........................................................274
ASSEMBLY ......................................................277
Assembly (1) .........................................................277
Adjustment ............................................................290
Assembly (2) .........................................................292
SERVICE DATA AND SPECIFICATIONS
(SDS) ................................................................
298
General Specification ............................................298
Vehicle Speed When Shifting Gears .....................298
Vehicle Speed When Performing and Releasing
Complete Lock-up .................................................
299
Stall Speed ............................................................299

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-35
< SERVICE INFORMATION >
D
E
F
G
H
I
J
K
L
MA
B
AT
N
O
P
The necessary and adequate line pressure for shift change is set.
For this reason, line pressure pattern setting corresponds to input
torque and gearshift selection. Also, line pressure characteristic is
set according to engine speed, during engine brake operation.
At Low Fluid Temperature
When the A/T fluid temperature drops below the prescribed tempera-
ture, in order to speed up the action of each friction element, the line
pressure is set higher than the normal line pressure characteristic.
Shift ControlINFOID:0000000003532234
The clutch pressure control solenoid is controlled by the signals from the switches and sensors. Thus, the
clutch pressure is adjusted to be appropriate to the engine load state and vehicle driving state. It becomes
possible to finely control the clutch hydraulic pressure with high precision and a smoother shift change charac-
teristic is attained.
SHIFT CHANGE
The clutch is controlled with the optimum timing and oil pressure by the engine speed, engine torque informa-
tion, etc.
Shift Change System Diagram
PCIA0010E
PCIA0011E
PCIA0012E

AT-36
< SERVICE INFORMATION >
A/T CONTROL SYSTEM
*1: Full phase real-time feedback control monitors movement of gear ratio at gear change, and controls oil
pressure at real-time to achieve the best gear ratio.
Lock-up ControlINFOID:0000000003532235
The torque converter clutch piston in the torque converter is engaged to eliminate torque converter slip to
increase power transmission efficiency.
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.
Lock-up Operation Condition Table
TORQUE CONVERTER CLUTCH CONTROL VALVE CONTROL
Lock-up Control System Diagram
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
PCIA0013E
Select lever D position 4 position 3 position 2 position
Gear position 5 4 4 3 2
Lock-up×–×××
Slip lock-up××–––
PCIA0014E

TROUBLE DIAGNOSIS
AT-51
< SERVICE INFORMATION >
D
E
F
G
H
I
J
K
L
MA
B
AT
N
O
P
Circuit DiagramINFOID:0000000003532247
Inspections Before Trouble DiagnosisINFOID:0000000003532248
A/T FLUID CHECK
Fluid Leakage and Fluid Level Check
• Inspect for fluid leakage and check the fluid level. Refer to AT-13, "Changing Automatic Transmission Fluid
(ATF)".
BCWA0496E

AT-92
< SERVICE INFORMATION >
DTC U1000 CAN COMMUNICATION LINE
Wiring Diagram - AT - CAN
INFOID:0000000003532264
TCM Input/Output Signal Reference Values
Refer to AT-82, "TCM Input/Output Signal Reference Value".
BCWA0320E

DTC P0615 START SIGNAL CIRCUIT
AT-95
< SERVICE INFORMATION >
D
E
F
G
H
I
J
K
L
MA
B
AT
N
O
P
Wiring Diagram - AT - STSIGINFOID:0000000003532271
TCM Input/Output Signal Reference Values
Refer to AT-82, "TCM Input/Output Signal Reference Value".
Diagnosis ProcedureINFOID:0000000003532272
1.CHECK STARTER RELAY
BCWA0321E

AT-100
< SERVICE INFORMATION >
DTC P0705 PARK/NEUTRAL POSITION SWITCH
Wiring Diagram - AT - PNP/SW
INFOID:0000000003532283
Diagnosis ProcedureINFOID:0000000003532284
1.CHECK PNP SW CIRCUIT
With CONSULT-II
BCWA0520E