2003 NISSAN X-TRAIL low oil pressure

AT-4
Differential Side Oil Seal Replacement .................457
Revolution Sensor Replacement ..........................457
REMOVAL AND INSTALLATION ...........................458
Removal ...............................................................458
Installation .............................................................459
OVERHAUL .............................................................461
Components .........................................................461
Oil Channel ...........................................................464
Locations of Adjusting Shims, Needle Bearings,
Thrust Washers and Snap Rings ..........................465
DISASSEMBLY .......................................................466
Disassembly .........................................................466
REPAIR FOR COMPONENT PARTS ......................482
Manual Shaft ........................................................482
Oil Pump ...............................................................485
Control Valve Assembly ........................................489
Control Valve Upper Body ....................................498
Control Valve Lower Body ....................................502
Reverse Clutch .....................................................504
High Clutch ...........................................................507
Forward and Overrun Clutches ............................512
Low & Reverse Brake ...........................................518
Rear Internal Gear, Forward Clutch Hub and Over-
run Clutch Hub ......................................................521
Output Shaft, Idler Gear, Reduction Pinion Gear and
Bearing Retainer ...................................................525
Band Servo Piston Assembly ...............................530
Final Drive ............................................................535ASSEMBLY ............................................................. 540
Assembly (1) ......................................................... 540
Adjustment (1) ....................................................... 541
Assembly (2) ......................................................... 546
Adjustment (2) ....................................................... 553
Assembly (3) ......................................................... 556
SERVICE DATA AND SPECIFICATIONS (SDS) .... 563
General Specifications .......................................... 563
Shift Schedule ....................................................... 563
Stall Revolution ..................................................... 563
Line Pressure ........................................................ 563
Control Valves ....................................................... 564
Accumulator .......................................................... 564
Clutch and Brakes ................................................. 564
Final Drive ............................................................. 566
Planetary Carrier and Oil Pump ............................ 567
Input Shaft ............................................................. 568
Reduction Pinion Gear .......................................... 568
Band Servo ........................................................... 569
Output Shaft .......................................................... 569
Bearing Retainer ................................................... 569
Total End Play ....................................................... 569
Reverse Clutch End Play ...................................... 570
Removal and Installation ....................................... 570
Shift Solenoid Valves ............................................ 570
Solenoid Valves .................................................... 570
A/T Fluid Temperature Sensor .............................. 570
Revolution Sensor ................................................. 571
Dropping Resistor ................................................. 571

AT-20
OVERALL SYSTEM
l*1: Operates when overdrive control switch is set in “OFF” position.
l*2: Oil pressure is applied to both 2nd “apply” side and 3rd “release” side of band servo piston. However, brake band does not con-
tract because oil pressure area on the “release” side is greater than that on the “apply” side.
l*3: Oil pressure is applied to 4th “apply” side in condition *2 above, and brake band contracts.
l*4: A/T will not shift to 4th when overdrive control switch is set in “OFF” position.
l*5: Operates when overdrive control switch is “OFF”.
l:Operates.
lA: Operates when throttle opening is less than 3/16, activating engine brake.
lB: Operates during “progressive” acceleration.
lC: Operates but does not affect power transmission.
lD: Operates when throttle opening is less than 3/16, but does not affect engine brake.
POWER TRANSMISSION
“N” and “P” Positions
l“N” position
Power from the input shaft is not transmitted to the output shaft because the clutches do not operate.
l“P” position
NNEUTRAL
POSITION
D*41st *1D B B
Automatic
shift
1Û2Û3Û
4 2nd *1A B
3rd *1A *2C C B
*5
4th C *3C C
21st D B BAutomatic
shift
1Û2 2nd A B
11stBLocks (held
stationary) in
1st speed
1Ü2 2ndB Shift positionRever
se
clutch
5High
clutch
6For-
ward
clutch
15Over-
run
clutch
17Band servo
Forward
one-way
clutch
16Low
one-
way
clutch
18Low &
revers
e
brake
19Lock-
upRemarks
2nd
apply3rd
releas
e4th
apply

AT-34
OVERALL SYSTEM
Overrun clutch control valve Switches hydraulic circuits to prevent engagement of the overrun clutch simultaneously with appli-
cation of the brake band in D
4. (Interlocking occurs if the overrun clutch engages during D4.)
1st reducing valve Reduces low & reverse brake pressure to dampen engine-brake shock when down-shifting from
the “1” position 1
2to 11.
Overrun clutch reducing valve Reduces oil pressure directed to the overrun clutch and prevents engine-brake shock.
In “1” and “2” positions, line pressure acts on the overrun clutch reducing valve to increase the
pressure-regulating point, with resultant engine brake capability.
Torque converter relief valve Prevents an excessive rise in torque converter pressure.
Torque converter clutch control
valve, plug and sleeveActivates or inactivates the lock-up function.
Also provides smooth lock-up through transient application and release of the lock-up system.
1-2 accumulator valve and piston Dampens the shock encountered when 2nd gear band servo contracts, and provides smooth
shifting.
3-2 timing valve Switches oil pressure with 3-2 timing valve according to throttle opening.
Shuttle control valve Reduces shock when down-shifting from 3rd to 2nd and regulates overrun clutch.
Cooler check valve Regulates oil pressure which causes lock-up when driving at low speeds.Valve name Function

TROUBLE DIAGNOSIS — BASIC INSPECTION
AT-69
[EURO-OBD]
D
E
F
G
H
I
J
K
L
MA
B
AT
5. Start engine and measure line pressure at idle and stall speed.
lWhen measuring line pressure at stall speed, follow the
stall test procedure.
Line pressure: Refer toAT-563, "
SERVICE DATA AND SPECIFI-
CATIONS (SDS)".
JUDGEMENT OF LINE PRESSURE TEST
Road TestECS004QT
DESCRIPTION
lThe purpose of the test is to determine overall performance of A/
T and analyze causes of problems.
lThe road test consists of the following three parts:
1. Check before engine is started
2. Check at idle
SAT493G
Judgement Suspected parts
At idleLine pressure is low in all positions.
lOil pump wear
lControl piston damage
lPressure regulator valve or plug sticking
lSpring for pressure regulator valve damaged
lFluid pressure leakage between oil strainer and pressure regulator valve
lClogged strainer
Line pressure is low in particular posi-
tion.
lFluid pressure leakage between manual valve and particular clutch
lFor example, line pressure is:
-Low in “R” and “1” positions, but
-Normal in “D” and “2” positions.
Therefore, fluid leakage exists at or around low and reverse brake circuit.
Refer to “CLUTCH AND BAND CHART”,AT-19, "
CLUTCH AND BAND
CHART".
Line pressure is high.
lMaladjustment of throttle position sensor
lA/T fluid temperature sensor damaged
lLine pressure solenoid valve sticking
lShort circuit of line pressure solenoid valve circuit
lPressure modifier valve sticking
lPressure regulator valve or plug sticking
lOpen in dropping resistor circuit
At stall
speedLine pressure is low.
lMaladjustment of throttle position sensor
lLine pressure solenoid valve sticking
lShort circuit of line pressure solenoid valve circuit
lPressure regulator valve or plug sticking
lPressure modifier valve sticking
lPilot valve sticking
SAT786A

TROUBLE DIAGNOSIS — GENERAL DESCRIPTION
AT-93
[EURO-OBD]
D
E
F
G
H
I
J
K
L
MA
B
AT
Clutches or brakes slip somewhat in
starting.ON vehicle1. Fluid levelAT-64,
"FLUID
LEVEL
CHECK"
¬
2. Control cable adjustmentAT-456,
"Control
Cable
Adjustment"
¬
3. Throttle position sensor (Accelerator
pedal position (App) sensor) AdjustmentEC-154, "
DTC P0121 APP
SENSOR"
4. Line pressure testAT-68, "
Line
Pressure
Te s t"
¬
5. Line pressure solenoid valveAT-436,
"LINE
PRES-
SURE
SOLENOID
VA LV E"
AT-186,
"DTC P0745
LINE PRES-
SURE
SOLENOID
VA LV E"
6. Control valve assemblyAT-454,
"Control
Va lv e
Assembly
and Accu-
mulators"
¬
7. Accumulator N-DAT-454,
"Control
Va lv e
Assembly
and Accu-
mulators"
¬
OFF vehicle8. Forward clutchAT-512,
"Forward
and Overrun
Clutches"
¬
9. Reverse clutchAT-504,
"Reverse
Clutch"
¬
10. Low & reverse brakeAT-518,
"Low&
Reverse
Brake"
¬
11. Oil pumpAT-485, "
Oil
Pump"¬
12. Torque converterAT-465,
"Locations
of Adjusting
Shims, Nee-
dle Bear-
ings, Thrust
Washers
and Snap
Rings"
¬ Symptom Condition Diagnostic ItemReference Page
Except for
Euro-OBDEURO-OBD

TROUBLE DIAGNOSIS — GENERAL DESCRIPTION
AT-113
[EURO-OBD]
D
E
F
G
H
I
J
K
L
MA
B
AT
Vehicle will not run in any position.ON vehicle1. Fluid levelAT-64,
"FLUID
LEVEL
CHECK"
¬
2. Control cable adjustmentAT-456,
"Control
Cable
Adjustment"
¬
3. Line pressure testAT-68, "
Line
Pressure
Te s t"
¬
4. Line pressure solenoid valveAT-436,
"LINE
PRES-
SURE
SOLENOID
VA LV E"
AT-186,
"DTC P0745
LINE PRES-
SURE
SOLENOID
VA LV E"
OFF vehicle5. Oil pumpAT-485, "
Oil
Pump"¬
6. High clutchAT-507,
"High
Clutch"
¬
7. Brake bandAT-530,
"Band
Servo Pis-
ton Assem-
bly"
¬
8. Low & reverse brakeAT-518,
"Low&
Reverse
Brake"
¬
9. Torque converterAT-465,
"Locations
of Adjusting
Shims, Nee-
dle Bear-
ings, Thrust
Washers
and Snap
Rings"
¬
10. Parking componentsAT-461,
"Compo-
nents"
¬
Transmission noise in “D”, “2”, “1”
and “R” positions.ON vehicle 1. Fluid levelAT-64,
"FLUID
LEVEL
CHECK"
¬
OFF vehicle 2. Torque converterAT-465,
"Locations
of Adjusting
Shims, Nee-
dle Bear-
ings, Thrust
Washers
and Snap
Rings"
¬ Symptom Condition Diagnostic ItemReference Page
Except for
Euro-OBDEURO-OBD

AT-172
[EURO-OBD]
DTC P0734 A/T 4TH GEAR FUNCTION
DTC P0734 A/T 4TH GEAR FUNCTION
PFP:31940
DescriptionECS0 04 RM
lThis is an OBD-II self-diagnostic item and not available in TCM self-diagnosis.
lThis malfunction will not be detected while the O/D OFF indicator lamp is indicating another self-diagnosis
malfunction.
lThis malfunction is detected when the A/T does not shift into fourth gear position or the torque converter
clutch does not lock up as instructed by the TCM. This is not caused by electrical malfunction (circuits
open or shorted) but by mechanical malfunction such as control valve sticking, improper solenoid valve
operation, malfunctioning oil pump or torque converter clutch, etc.
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Specification data are reference values.
TCM TERMINALS AND REFERENCE VALUE
Remarks: Specification data are reference values.
ON BOARD DIAGNOSTIC LOGIC
This diagnosis monitors actual gear position by checking the torque converter slip ratio calculated by TCM as
follows:
Torque converter slip ratio = A x C/B
A: Output shaft revolution signal from revolution sensor
B: Engine speed signal from ECM
C: Gear ratio determined as gear position which TCM supposes
Gear position 1 2 3 4
Shift solenoid valve A ON (Closed) OFF (Open) OFF (Open) ON (Closed)
Shift solenoid valve B ON (Closed) ON (Closed) OFF (Open) OFF (Open)
Monitor item Condition Specification
Line pressure solenoid valve dutySmall throttle opening
(Low line pressure)
¯
Large throttle opening
(High line pressure)Approximately 24%
¯
Approximately 95%
Te r m i -
nal No.Wire color Item ConditionJudgement stan-
dard
(Approx.)
1R/WLine pressure
solenoid valveWhen releasing accelerator pedal
after warming up engine.1.5 - 3.0V
When depressing accelerator pedal
fully after warming up engine.0V
2P/BLine pressure
solenoid valve
(with dropping
resistor)When releasing accelerator pedal
after warming up engine.5 - 14V
When depressing accelerator pedal
fully after warming up engine.0V
11 L /WShift solenoid
valve AWhen shift solenoid valve A oper-
ates.
(When driving in “D
1”or“D4”.)Battery voltage
When shift solenoid valve A does not
operate.
(When driving in “D
2”or“D3”.)0V
12 L/YShift solenoid
valve BWhen shift solenoid valve B oper-
ates.
(When driving in “D
1”or“D2”.)Battery voltage
When shift solenoid valve B does not
operate.
(When driving in “D
3”or“D4”.)0V

AT-186
[EURO-OBD]
DTC P0745 LINE PRESSURE SOLENOID VALVE
DTC P0745 LINE PRESSURE SOLENOID VALVE
PFP:31940
DescriptionECS004RU
The line pressure solenoid valve regulates the oil pump discharge
pressure to suit the driving condition in response to a signal sent
from the TCM.
The line pressure duty cycle value is not consistent when the
closed throttle position switch is “ON”. To confirm the line
pressure duty cycle at low pressure, the accelerator (throttle)
should be open until the closed throttle position switch is
“OFF”.
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Specification data are reference values.
NOTE:
The line pressure duty cycle value is not consistent when the closed throttle position switch is “ON”. To confirm the line pressure duty
cycle at low pressure, the accelerator (throttle) should be open until the closed throttle position switch is “OFF”.
TCM TERMINALS AND REFERENCE VALUE
Remarks: Specification data are reference values.
ON BOARD DIAGNOSIS LOGIC
SCIA0735E
Monitor item Condition Specification
Line pressure solenoid valve dutySmall throttle opening
(Low line pressure)
¯
Large throttle opening
(High line pressure)Approximately 24%
¯
Approximately 95%
Te r m i -
nal No.Wire color Item ConditionJudgement stan-
dard
(Approx.)
1R/WLine pressure
solenoid valveWhen releasing accelerator pedal
after warming up engine.1.5 - 2.5V
When depressing accelerator pedal
fully after warming up engine.0V
2P/BLine pressure
solenoid valve
(with dropping
resistor)When releasing accelerator pedal
after warming up engine.5 - 14V
When depressing accelerator pedal
fully after warming up engine.0V
Diagnostic trouble code Malfunction is detected when ... Check items (Possible cause)
: L/PRESS SOL/CIRC
TCM detects an improper voltage drop
when it tries to operate the solenoid valve.
lHarness or connectors
(The solenoid circuit is open or shorted.)
lLine pressure solenoid valve
: P0745