2004 INFINITI QX56 oil pressure

QUICK REFERENCE CHART: QX562004

QUICK REFERENCE CHART: QX56PFP:00000
Engine Tune-Up DataELS000YK
Cylinder arrangementV- 8
Displacement 5,552 cm
3 (338.80 in3 )
Bore and stroke 98 x 92 mm (3.86 x 3.62 in)
Valve arrangement DOHC
Firing order 1-8-7-3-6-5-4-2
Number of piston rings Compression 2
Oil 1
Number of main bearings 5
Compression ratio 9.8:1
Compression pressure Standard
1,520 kPa (15.5 kg/cm
2 , 220 psi) / 200 rpm
Minimum 1,324 kPa (13.5 kg/cm
2 , 192 psi) / 200 rpm
Differential limit between cylinders 98 kPa (1.0 kg/cm
2 , 14 psi) / 200 rpm
Cylinder number
Valve timing Unit: degree
abcde f
232 ° 230° 2° 48° 3° 49°
SEM957C
PBIC0187E

ACS-12
[ICC]
LASER BEAM AIMING ADJUSTMENT
Revision: August 20072004 QX56
LASER BEAM AIMING ADJUSTMENTPFP:00026
Outline of Laser Beam Aiming Adjustment ProcedureEKS007TI
CAUTION:

The laser beam aiming adjustment cannot be performed without CONSULT-II.

The laser beam aiming adjustment must be performed every time the ICC sensor is removed,
installed or has been moved as a result of a collision.
1. Prepare the vehicle and the work area.
2. Set up the ICC target board.
3. Adjust the sensor following the procedure on CONSULT-II.
4. Check system operation after the adjustment.
PreparationEKS007PC

Place the vehicle on level ground. Shift the transmission into "P" position and release the parking brake.

Adjust the tire pressure to the specified value.

See that there is no load in the vehicle. Coolant, engine oil and fuel should be filled to correct level.

Check that the vehicle suspension has been adjusted to the standard height by the load leveling rear air
suspension system. Refer to RSU-12, "
Basic Inspection" .

Clean the ICC sensor with a soft cloth.
Setting up the ICC Target BoardEKS007PE
CAUTION:
Accuracy in setting up the ICC target board is essential for the laser beam aiming adjustment.
ADJUSTING HEIGHT OF THE ICC TARGET BOARD
1. Attach a triangle scale as shown.Tool number : KV99110100 (J-45718)
WKIA1848E
WKIA1849E

AT-4Revision: August 20072004 QX56 A/T Does Not Shift: 2nd gear → 1st gear .............227
Vehicle Does Not Decelerate By Engine Brake ....230
SHIFT CONTROL SYSTEM ....................................233
Control Device Removal and Installation ..............233
Adjustment of A/T Position ...................................234
Checking of A/T Position ......................................234
A/T SHIFT LOCK SYSTEM .....................................236
Description ............................................................236
Shift Lock System Electrical Parts Location .........236
Wiring Diagram — A/T — SHIFT ..........................237
Shift Lock Control Unit Reference Values .............238
Component Inspection ..........................................239
ON-VEHICLE SERVICE ..........................................241
Control Valve With TCM and A/T Fluid Temperature
Sensor 2 ...............................................................241
Rear Oil Seal ........................................................252
AIR BREATHER HOSE ...........................................253
Removal and Installation ......................................253
TRANSMISSION ASSEMBLY ................................255
Removal and Installation (4x2) .............................255
Removal and Installation (4x4) .............................258
OVERHAUL .............................................................261
Components .........................................................261
Oil Channel ...........................................................269
Locations of Adjusting Shims, Needle Bearings,
Thrust Washers and Snap Rings ..........................271
DISASSEMBLY .......................................................273
Disassembly .........................................................273REPAIR FOR COMPONENT PARTS ...................... 290
Oil Pump ............................................................... 290
Front Sun Gear, 3rd One-Way Clutch ................... 292
Front Carrier, Input Clutch, Rear Internal Gear ..... 295
Mid Sun Gear, Rear Sun Gear, High and Low
Reverse Clutch Hub .............................................. 300
High and Low Reverse Clutch .............................. 305
Direct Clutch ......................................................... 307
ASSEMBLY ............................................................. 309
Assembly (1) ......................................................... 309
Adjustment ............................................................ 322
Assembly (2) ......................................................... 324
SERVICE DATA AND SPECIFICATIONS (SDS) .... 331
General Specifications .......................................... 331
Vehicle Speed When Shifting Gears ..................... 331
Vehicle Speed When Performing and Releasing
Complete Lock-up ................................................. 332
Vehicle Speed When Performing and Releasing
Slip Lock-up .......................................................... 332
Stall Speed ............................................................ 332
Line Pressure ........................................................ 332
A/T Fluid Temperature Sensor .............................. 332
Turbine Revolution Sensor .................................... 332
Vehicle Speed Sensor A/T (Revolution Sensor) ... 332
Reverse brake ....................................................... 333
Total End Play ....................................................... 333

AT-10
PREPARATION
Revision: August 20072004 QX56
PREPARATIONPFP:00002
Special Service ToolsUCS002C6
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Tool number
(Kent-Moore No.)
Tool nameDescription
ST2505S001
(J-34301-C)
Oil pressure gauge set
1 ST25051001
(—)
Oil pressure gauge
2 ST25052000
(—)
Hose
3 ST25053000
(—)
Joint pipe
4 ST25054000
(—)
Adapter
5 ST25055000
(—)
AdapterMeasuring line pressure
KV31103600
(J-45674)
Joint pipe adapter
(With ST25054000)Measuring line pressure
ST33400001
(J-26082)
Drift
a: 60 mm (2.36 in) dia.
b: 47 mm (1.85 in) dia.

Installing rear oil seal (2WD models)

Installing oil pump housing oil seal
KV31102400
(J-34285 and J-34285-87)
Clutch spring compressor
a: 320 mm (12.60 in)
b: 174 mm (6.85 in)Installing reverse brake return spring retainer
ZZA0600D
ZZA1227D
NT086
NT423

A/T CONTROL SYSTEM
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Revision: August 20072004 QX56
Line Pressure ControlUCS002C H

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.

This line pressure solenoid controls the pressure regulator valve as the signal pressure and adjusts the
pressure of the operating oil discharged from the oil pump to the line pressure most appropriate to the
driving state.
LINE PRESSURE CONTROL IS BASED ON THE TCM LINE PRESSURE CHARACTERISTIC
PATTERN

The TCM has stored in memory a number of patterns for the optimum line pressure characteristic for the
driving state.

In order to obtain the most appropriate line pressure characteristic to meet the current driving state, the
TCM controls the line pressure solenoid current valve and thus controls the line pressure.
Normal Control
Each clutch is adjusted to the necessary pressure to match the
engine drive force.
Back-up Control (Engine Brake)
When the select operation is performed during driving and the trans-
mission is shifted down, the line pressure is set according to the
vehicle speed.
PCIA0007E
PCIA0008E
PCIA0009E

AT-34
A/T CONTROL SYSTEM
Revision: August 20072004 QX56
During Shift Change
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 ControlUCS002CI
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.
PCIA0010E
PCIA0 011 E
PCIA0012E

A/T CONTROL SYSTEM
AT-35
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Revision: August 20072004 QX56
Shift Change System Diagram
*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 ControlUCS002CJ
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.
PCIA0013E
Select lever D position 4 position 3 position 2 position
Gear position 5 4 4 3 2
Lock-up×–×××
Slip lock-up××–––
PCIA0014E

A/T CONTROL SYSTEM
AT-37
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Revision: August 20072004 QX56
Engine Brake ControlUCS002CK

The forward one-way clutch transmits the drive force from the engine to the rear wheels. But the reverse
drive from the rear wheels is not transmitted to the engine because the one-way clutch is idling.
Therefore, the low coast brake solenoid is operated to prevent the forward one-way clutch from idling and
the engine brake is operated in the same manner as conventionally.

The operation of the low coast brake solenoid switches the low coast brake switching valve and controls
the coupling and releasing of the low coast brake.
The low coast brake reducing valve controls the low coast brake coupling force.
Control ValveUCS002CL
FUNCTION OF CONTROL VALVE
SCIA1520E
Name Function
Torque converter regulator valveIn order to prevent the pressure supplied to the torque converter from being excessive,
the line pressure is adjusted to the optimum pressure (torque converter operating pres-
sure).
Pressure regulator valve
Pressure regulator plug
Pressure regulator sleeveAdjusts the oil discharged from the oil pump to the optimum pressure (line pressure) for
the driving state.
Front brake control valveWhen the front brake is coupled, adjusts the line pressure to the optimum pressure
(front brake pressure) and supplies it to the front brake. (In 1st, 2nd, 3rd, and 5th gears,
adjusts the clutch pressure.)
Accumulator control valveAdjusts the pressure (accumulator control pressure) acting on the accumulator piston
and low coast reducing valve to the pressure appropriate to the driving state.
Pilot valve AAdjusts the line pressure and produces the constant pressure (pilot pressure) required
for line pressure control, shift change control, and lock-up control.
Pilot valve BAdjusts the line pressure and produces the constant pressure (pilot pressure) required
for shift change control.
Low coast brake switching valve During engine braking, supplies the line pressure to the low coast brake reducing valve.
Low coast brake reducing valveWhen the low coast brake is coupled, adjusts the line pressure to the optimum pressure
(low coast brake pressure) and supplies it to the low coast brake.
N-R accumulator Produces the stabilizing pressure for when N-R is selected.
Direct clutch piston switching valve Operates in 4th gear and switches the direct clutch coupling capacity.
High and low reverse clutch control valveWhen the high and low reverse clutch is coupled, adjusts the line pressure to the opti-
mum pressure (high and low reverse clutch pressure) and supplies it to the high and low
reverse clutch. (In 1st, 3rd, 4th and 5th gears, adjusts the clutch pressure.)