low oil pressure INFINITI QX56 2006 Factory Service Manual

ACS-12
[ICC]
LASER BEAM AIMING ADJUSTMENT
Revision: November 20092006 QX56
LASER BEAM AIMING ADJUSTMENTPFP:00026
Outline of Laser Beam Aiming Adjustment ProcedureEKS00BLN
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. For details, refer to Technical Service Bulletin.
3. Adjust the sensor following the procedure on CONSULT-II.
4. Check system operation after the adjustment.
PreparationEKS00BLO

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 sensor with a soft cloth.
Setting up the ICC Target BoardEKS00BLP
CAUTION:
Accuracy in setting up the ICC target board is essential for the laser beam aiming adjustment.
For details, refer to Technical Service Bulletin.
ADJUSTING HEIGHT OF THE TARGET
1. Attach a triangle scale as shown.Tool number : KV99110100 (J-45718)
LKIA0632E
WKIA1849E

AT-4Revision: November 20092006 QX56
Shift Lock Control Unit Reference Values ............
.223
Component Inspection ......................................... .224
SHIFT CONTROL SYSTEM ................................... .226
Control Device Removal and Installation ............. .226
Adjustment of A/T Position .................................. .227
Checking of A/T Position ..................................... .227
ON-VEHICLE SERVICE ......................................... .228
Oil Pan ................................................................. .228
Control Valve With TCM and A/T Fluid Temperature
Sensor 2 .............................................................. .230
Rear Oil Seal ....................................................... .240
AIR BREATHER HOSE .......................................... .241
Removal and Installation ..................................... .241
TRANSMISSION ASSEMBLY ............................... .243
Removal and Installation (2WD) .......................... .243
Removal and Installation (4WD) .......................... .246
OVERHAUL ............................................................ .250
Components ........................................................ .250
Oil Channel .......................................................... .258
Locations of Adjusting Shims, Needle Bearings,
Thrust Washers and Snap Rings ......................... .260
DISASSEMBLY ...................................................... .264
Disassembly ........................................................ .264
REPAIR FOR COMPONENT PARTS ..................... .282
Oil Pump .............................................................. .282Front Sun Gear, 3rd One-Way Clutch ..................
.284
Front Carrier, Input Clutch, Rear Internal Gear .... .286
Mid Sun Gear, Rear Sun Gear, High and Low
Reverse Clutch Hub ............................................. .291
High and Low Reverse Clutch ............................. .296
Direct Clutch ........................................................ .298
ASSEMBLY ............................................................ .300
Assembly (1) ........................................................ .300
Adjustment ........................................................... .313
Assembly (2) ........................................................ .316
SERVICE DATA AND SPECIFICATIONS (SDS) ... .323
General Specifications ......................................... .323
Vehicle Speed When Shifting Gears .................... .323
Vehicle Speed When Performing and Releasing
Complete Lock-up ................................................ .324
Vehicle Speed When Performing and Releasing
Slip Lock-up ......................................................... .324
Stall Speed ........................................................... .324
Line Pressure ....................................................... .324
A/T Fluid Temperature Sensor ............................. .324
Turbine Revolution Sensor ................................... .324
Vehicle Speed Sensor A/T (Revolution Sensor) .. .324
Reverse brake ...................................................... .325
Total End Play ...................................................... .325

A/T CONTROL SYSTEMAT-33
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Revision: November 2009 2006 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 ControlECS00CE0
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
PCIA0011E
PCIA0012E

AT-36
A/T CONTROL SYSTEM
Revision: November 20092006 QX56
Engine Brake ControlECS00CE2

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 ValveECS00CE3
FUNCTION OF CONTROL VALVE
SCIA1520E
NameFunction
Torque converter regulator valve In 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 sleeve Adjusts the oil discharged from the oil pump to the optimum pressure (line pressure) for
the driving state.
Front brake control valve When 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 valve Adjusts 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 A Adjusts the line pressure and produces the constant pressure (pilot pressure) required
for line pressure control, shift change control, and lock-up control.
Pilot valve B Adjusts 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 valve When 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 valve When 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.)

A/T CONTROL SYSTEMAT-37
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Revision: November 2009 2006 QX56
FUNCTION OF PRESSURE SWITCH
Input clutch control valveWhen the input clutch is coupled, adjusts the line pressure to the optimum pressure
(input clutch pressure) and supplies it to the input clutch. (In 4th and 5th gears, adjusts
the clutch pressure.)
Direct clutch control valve When the direct clutch is coupled, adjusts the line pressure to the optimum pressure
(direct clutch pressure) and supplies it to the direct clutch. (In 2nd, 3rd, and 4th gears,
adjusts the clutch pressure.)
TCC control valve
TCC control plug
TCC control sleeve Switches the lock-up to operating or released. Also, by performing the lock-up operation
transiently, lock-up smoothly.
Torque converter lubrication valve Operates during lock-up to switch the torque converter, cooling, and lubrication system
oil path.
Cool bypass valve Allows excess oil to bypass cooler circuit without being fed into it.
Line pressure relief valve Discharges excess oil from line pressure circuit.
N-D accumulator Produces the stabilizing pressure for when N-D is selected.
Manual valve Sends line pressure to each circuit according to the select position. The circuits to which
the line pressure is not sent drain.
Name
Function
NameFunction
Pressure switch 1 (FR/B) Detects any malfunction in the front brake hydraulic pressure. When it detects any mal-
function, it puts the system into fail-safe mode.
Pressure switch 2 (LC/B) Detects any malfunction in the low coast brake hydraulic pressure. When it detects any
malfunction, it puts the system into fail-safe mode.
Pressure switch 3 (I/C) Detects any malfunction in the input clutch hydraulic pressure. When it detects any mal-
function, it puts the system into fail-safe mode.
Pressure switch 5 (D/C) Detects any malfunction in the direct clutch hydraulic pressure. When it detects any mal-
function, it puts the system into fail-safe mode.
Pressure switch 6 (HLR/C) Detects any malfunction in the high and low reverse clutch hydraulic pressure. When it
detects any malfunction, it puts the system into fail-safe mode.

AT-52
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
8. Cool down the ATF.
CAUTION:
Run the engine at idle for at least one minute.
Judgement of Stall Test
O: Stall speed within standard value position
H: Stall speed higher than standard value
L: Stall speed lower than standard value
Stall test standard value position
LINE PRESSURE TEST
Line Pressure Test Port
Line Pressure Test Procedure
1. Inspect the amount of engine oil and replenish if necessary.
2. Drive the car for about 10 minutes to warm it up so that the ATF reaches in range of 50 to 80 °C (122 to
176° F), then inspect the amount of ATF and replenish if necessary.
NOTE:
The automatic fluid temperature rises in range of 50 to 80 °C (122 to 176 °F) during 10 minutes of
driving. Stall speed: 2,500 - 2,800 rpm
Selector lever position
Expected problem location
DR
Stall rotation HO

Forward brake

Forward one-way clutch

1st one-way clutch

3rd one-way clutch
OH

Reverse brake
LL

Engine and torque converter one-way clutch
HH

Line pressure low
Does not shift-up D position 1 → 2 Slipping in 2nd, 3rd, 4th gears Direct clutch slippage
Does not shift-up D position 2 → 3 Slipping in 3rd, 4th, 5th gears High and low reverse clutch slippage
Does not shift-up D position 3 → 4 Slipping in 4th, 5th gears Input clutch slippage
Does not shift-up D position 4 → 5 Slipping in 5th gear Front brake slippage
SCIA2187E

TROUBLE DIAGNOSISAT-53
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Revision: November 2009 2006 QX56
3. After warming up remove the oil pressure detection plug and
install the oil pressure gauge [ST2505S001(J-34301-C)].
CAUTION:
When using the oil pressure gauge, be sure to use the O-
ring attached to the oil pressure detection plug.
4. Securely engage the parking brake so that the tires do not turn.
5. Start the engine, then measure the line pressure at both idle and the stall speed.
CAUTION:

Keep the brake pedal pressed all the way down during
measurement.

When measuring the line pressure at the stall speed,
refer to AT- 5 1 , "
STALL TEST" .
6. After the measurements are complete, install the oil pressure detection plug and tighten to the regulation torque below.
CAUTION:
Do not reuse the O-ring.
Line Pressure
SCIA5309E
SCIA1224E
:7.3 N·m (0.74 kg-m, 65 in-lb)SAT493G
Engine speed Line pressure [kPa (kg/cm2 , psi)]
R position D position
At idle speed 425 - 465 (4.3 - 4.7, 62 - 67) 379 - 428 (3.9 - 4.4, 55 - 62)
At stall speed 1,605 - 1,950 (16.4 - 19.9, 233 - 283) 1,310 - 1,500 (13.4 - 15.3, 190 - 218)

AT-54
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
Judgement of Line Pressure Test
ROAD TEST
Description

The road test inspects overall performance of the A/T and analyzes possible malfunction causes.

The road test is carried out in the following three stages.
1. Check before engine is started. Refer to AT- 5 5
.
2. Check at idle. Refer to AT- 5 5
.
3. Cruise test

Inspect all the items from Part 1 to Part 3. Refer to AT- 5 6 , AT- 5 8 , AT- 5 9 .

Before beginning the road test, check the test procedure and inspection items.

Test all inspection items until the symptom is uncovered. Diagnose NG items when all road tests are com-
plete.
Judgement Possible cause
Idle speed Low for all positions
(P, R, N, D)
Possible causes include malfunctions in the pressure supply system and low oil pump output.
For example

Oil pump wear

Pressure regulator valve or plug sticking or spring fatigue

Oil strainer

oil pump
pressure regulator valve passage oil leak

Engine idle speed too low
Only low for a spe-
cific position Possible causes include an oil pressure leak in a passage or device related to the position after
the pressure is distributed by the manual valve.
High Possible causes include a sensor malfunction or malfunction in the line pressure adjustment func-
tion.
For example

Accelerator pedal position signal malfunction

ATF temperature sensor malfunction

Line pressure solenoid malfunction (sticking in “
OFF” state, filter clog, cut line)

Pressure regulator valve or plug sticking
Stall speed Oil pressure does
not rise higher than
the oil pressure for
idle.
Possible causes include a sensor malfunction or malfunction in the pressure adjustment function.
For example

Accelerator pedal position signal malfunction

TCM breakdown

Line pressure solenoid malfunction (shorting, sticking in
“ ON ” state)

Pressure regulator valve or plug sticking

Pilot valve sticking or pilot filter clogged
The pressure rises,
but does not enter
the standard posi-
tion. Possible causes include malfunctions in the pressure supply system and malfunction in the pres-
sure adjustment function.
For example

Accelerator pedal position signal malfunction

Line pressure solenoid malfunction (sticking, filter clog)

Pressure regulator valve or plug sticking

Pilot valve sticking or pilot filter clogged
Only low for a spe-
cific position Possible causes include an oil pressure leak in a passage or device related to the position after
the pressure is distributed by the manual valve.

AT-68
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
22
Slips/Will
Not
Engage When
“D ” position,
remains in 5th gear. ON vehicle1. Fluid level and state
AT- 5 1
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 111,
AT- 1 3 2

3. ATF pressure switch 1 and front brake solenoid valve AT- 1 5 9
,
AT- 1 4 3
4. Line pressure test AT- 5 2
5. CAN communication lineAT- 9 6
6. Control valve with TCMAT- 2 3 0
OFF vehicle7. Front brake (brake band)
AT- 2 6 48. Input clutchAT- 2 8 6
9. Gear systemAT- 2 5 0
10. High and low reverse clutchAT- 2 9 6
23Vehicle cannot be
started from D
1 .
Refer to AT-191, "
Vehi-
cle Cannot Be Started
From D1" . ON vehicle
1. Fluid level and state
AT- 5 1
2. Accelerator pedal position sensorAT- 1 2 4
3. Line pressure test AT- 5 2
4. CAN communication lineAT- 9 6
5. Control valve with TCMAT- 2 3 0
OFF vehicle6. Torque converter
AT- 2 6 4
7. Oil pump assemblyAT- 2 8 2
8. 3rd one-way clutchAT- 2 8 4
9. 1st one-way clutchAT- 2 9 1
10. Gear systemAT- 2 5 0
11. Reverse brakeAT- 2 6 4
12. Forward one-way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to
AT- 1 7
, AT- 1 8 .) AT- 2 6 4
13. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to
AT- 1 7
, AT- 1 8
.) AT- 2 6 4
24Does not lock-up.
Refer to
AT-203, "A/T
Does Not Perform
Lock-up" . ON vehicle1. Fluid level and state
AT- 5 1
2. Line pressure testAT- 5 2
3. Engine speed signalAT- 11 6
4. Turbine revolution sensorAT- 1 0 9
5. Torque converter clutch solenoid valve AT- 11 8
6. CAN communication line AT- 9 6
7. Control valve with TCMAT- 2 3 0
OFF vehicle8. Torque converter
AT- 2 6 49. Oil pump assemblyAT- 2 8 2
No. ItemsSymptom Condition Diagnostic ItemReference
page

AT-70
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
28
Slips/Will
Not
engage No shock at all or the
clutch slips when
vehicle changes
speed D
2
→ D3 . ON vehicle
1. Fluid level and state
AT- 5 1
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 111,
AT- 1 3 2
3. ATF pressure switch 6, high and low reverse clutch sole-
noid valve AT- 1 6 5,
AT- 1 5 1
4. CAN communication line AT- 9 6
5. Line pressure testAT- 5 2
6. Control valve with TCMAT- 2 3 0
OFF vehicle7. Torque converter
AT- 2 6 4
8. Oil pump assemblyAT- 2 8 2
9. 3rd one-way clutchAT- 2 8 4
10. Gear systemAT- 2 5 0
11. High and low reverse clutchAT- 2 9 6
12. Forward one- way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to
AT- 1 7
, AT- 1 8 .) AT- 2 6 4
13. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to
AT- 1 7
, AT- 1 8
.) AT- 2 6 4
29No shock at all or the
clutch slips when
vehicle changes
speed D
3
→ D4 . ON vehicle 1. Fluid level and state
AT- 5 1
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 111,
AT- 1 3 2
3. ATF pressure switch 3 and input clutch solenoid valve AT- 1 6 1,
AT- 1 3 9

4. ATF pressure switch 1 and front brake solenoid valve AT- 1 5 9
,
AT- 1 4 3
5. CAN communication line AT- 9 6
6. Line pressure testAT- 5 2
7. Control valve with TCMAT- 2 3 0
OFF vehicle8. Torque converter
AT- 2 6 4
9. Oil pump assemblyAT- 2 8 2
10. Input clutchAT- 2 8 6
11. Gear systemAT- 2 5 0
12. High and low reverse clutchAT- 2 9 6
13. Direct clutchAT- 2 9 8
No. ItemsSymptom Condition Diagnostic ItemReference
page