2007 NISSAN 350Z low oil pressure

AT-4Revision: 2006 November2007 350Z Oil Channel ...........................................................252
Locations of Adjusting Shims, Needle Bearings,
Thrust Washers and Snap Rings ..........................253
DISASSEMBLY .......................................................255
Disassembly .........................................................255
REPAIR FOR COMPONENT PARTS ......................271
Oil Pump ...............................................................271
Front Sun Gear, 3rd One-way Clutch ...................274
Front Carrier, Input Clutch, Rear Internal Gear ....276
Mid Sun Gear, Rear Sun Gear, High and Low
Reverse Clutch Hub .............................................281
High and Low Reverse Clutch ..............................286
Direct Clutch .........................................................288
ASSEMBLY .............................................................290Assembly (1) .........................................................290
Adjustment ............................................................302
Assembly (2) .........................................................304
SERVICE DATA AND SPECIFICATIONS (SDS) ....311
General Specifications ..........................................311
Vehicle Speed at Which Gear Shifting Occurs ......311
Vehicle Speed at Which Lock-up Occurs/Releases .311
Stall Speed ............................................................311
Line Pressure ........................................................311
A/T Fluid Temperature Sensor ..............................312
Turbine Revolution Sensor ....................................312
Vehicle Speed Sensor A/T (Revolution Sensor) ...312
Reverse Brake ......................................................312
Total End Play .......................................................312

A/T CONTROL SYSTEM
AT-35
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: 2006 November2007 350Z
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 converter clutch solenoid is varied to gradually 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 status, the torque converter 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 torque fluctuation and lock-up operates from low speed.
This raises the fuel efficiency for 4th and 5th gears at both low speed and when the accelerator has a low
degree of opening.
Engine Brake ControlNCS0001S

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 ValveNCS0001T
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.)

AT-36
A/T CONTROL SYSTEM
Revision: 2006 November2007 350Z
FUNCTION OF ATF PRESSURE SWITCH
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.)
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 valveWhen 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 sleeveSwitches the lock-up to operating or released. Also, by performing the lock-up operation
transiently, lock-up smoothly.
Torque converter lubrication valveOperates during lock-up to switch the torque converter, cooling, and lubrication system
oil passage.
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 valveSends line pressure to each circuit according to the select position. The circuits to which
the line pressure is not sent drain. Name Function
Name Function
ATF 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.

AT-50
TROUBLE DIAGNOSIS
Revision: 2006 November2007 350Z
8. Cool down the ATF.
CAUTION:
Run the engine at idle for at least one minute.
9. Repeat steps 5 through 8 with selector lever in “R” position.
Judgment 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 A/T fluid temperature rises in range of 50 to 80°C (122 to 176°F) during 10 minutes of driving.
Selector lever position
Expected problem location
“D” and “M” “R”
Stall speedHO

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

AT-52
TROUBLE DIAGNOSIS
Revision: 2006 November2007 350Z
Judgment of Line Pressure Test
ROAD TEST
Description

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

The road test is performed in the following three stages.
1. Check before engine is started. Refer to AT- 5 3 , "
Check Before Engine is Started" .
2. Check at idle. Refer to AT- 5 3 , "
Check at Idle" .
3. Cruise test
–Inspect all the items from Part 1 to Part 3. Refer to AT- 5 5 , "Cruise Test — Part 1" , AT- 5 7 , "Cruise Test —
Part 2" and AT- 5 8 , "Cruise Test — Part 3" .

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.
Judgment Possible cause
Idle speedLow for all positions
(“P”, “R”, “N”, “D”, “M”)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 specific
positionPossible causes include an oil pressure leak in a passage or device related to the position after
the pressure is distributed by the manual valve.
HighPossible causes include a sensor malfunction or malfunction in the line pressure adjustment
function.
For example

Accelerator pedal position signal malfunction

A/T fluid temperature sensor malfunction

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

Pressure regulator valve or plug sticking
Stall speedLine pressure does
not rise higher than
the line pressure for
idle.Possible causes include a sensor malfunction or malfunction in the pressure adjustment func-
tion.
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 position.Possible causes include malfunctions in the pressure supply system and malfunction in the
pressure 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 specific
positionPossible 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: 2006 November2007 350Z
28
Slips/Will
Not
EngageNo shock at all or the
clutch slips when
vehicle changes
speed D
2 → D3 or
M
2 → M3 .ON vehicle1. A/T fluid level and stateAT- 4 9
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 1 0 8,
AT- 1 3 9
3. High and low reverse clutch solenoid valveAT- 1 5 1
4. CAN communication lineAT- 9 4
5. Line pressure testAT- 5 0
6. Control valve with TCMAT- 2 1 5
OFF vehicle7. Torque converterAT- 2 5 5
8. Oil pump assemblyAT- 2 7 1
9. 3rd one-way clutchAT- 2 7 4
10. Gear systemAT- 2 4 6
11. High and low reverse clutchAT- 2 8 6
12. Forward one-way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to
AT-17, "
Cross-sectional View" .)AT- 2 5 5
13. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-17,
"Cross-sectional View" .)AT- 2 5 5
29No shock at all or the
clutch slips when
vehicle changes
speed D
3 → D4 or
M
3 → M4 .ON vehicle1. A/T fluid level and stateAT- 4 9
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 1 0 8,
AT- 1 3 9
3. Input clutch solenoid valveAT- 1 4 5
4. Front brake solenoid valveAT- 1 4 7
5. CAN communication lineAT- 9 4
6. Line pressure testAT- 5 0
7. Control valve with TCMAT- 2 1 5
OFF vehicle8. Torque converterAT- 2 5 5
9. Oil pump assemblyAT- 2 7 1
10. Input clutchAT- 2 7 6
11. Gear systemAT- 2 4 6
12. High and low reverse clutchAT- 2 8 6
13. Direct clutchAT- 2 8 8
No. Items Symptom Condition Diagnostic ItemReference
page

TROUBLE DIAGNOSIS
AT-69
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: 2006 November2007 350Z
30
Slips/Will
Not
EngageNo shock at all or the
clutch slips when
vehicle changes
speed D
4 → D5 or
M
4 → M5 .ON vehicle1. A/T fluid level and stateAT- 4 9
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT-108,
AT-139
3. Front brake solenoid valveAT-147
4. Direct clutch solenoid valveAT-149
5. CAN communication lineAT- 9 4
6. Line pressure testAT- 5 0
7. Control valve with TCMAT-215
OFF vehicle8. Torque converterAT-255
9. Oil pump assemblyAT-271
10. Front brake (brake band)AT-255
11. Input clutchAT-276
12. Gear systemAT-246
13. High and low reverse clutchAT-286
31When you press the
accelerator pedal and
shift speed D5 → D4
or M
5 → M4 the
engine idles or the A/
T slips.ON vehicle1. A/T fluid level and stateAT- 4 9
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT-108,
AT-139
3. Front brake solenoid valveAT-147
4. Direct clutch solenoid valveAT-149
5. CAN communication lineAT- 9 4
6. Line pressure testAT- 5 0
7. Control valve with TCMAT-215
OFF vehicle8. Torque converterAT-255
9. Oil pump assemblyAT-271
10. Input clutchAT-276
11. Gear systemAT-246
12. High and low reverse clutchAT-286
13. Direct clutchAT-288
No. Items Symptom Condition Diagnostic ItemReference
page

AT-70
TROUBLE DIAGNOSIS
Revision: 2006 November2007 350Z
32
Slips/Will
Not
EngageWhen you press the
accelerator pedal and
shift speed D4 → D3
or M
4 → M3 the
engine idles or the A/
T slips.ON vehicle1. A/T fluid level and stateAT- 4 9
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 1 0 8,
AT- 1 3 9
3. Input clutch solenoid valveAT- 1 4 5
4. Front brake solenoid valveAT- 1 4 7
5. CAN communication lineAT- 9 4
6. Line pressure testAT- 5 0
7. Control valve with TCMAT- 2 1 5
OFF vehicle8. Torque converter AT- 2 5 5
9. Oil pump assemblyAT- 2 7 1
10. 3rd one-way clutchAT- 2 7 4
11. Gear systemAT- 2 4 6
12. High and low reverse clutchAT- 2 8 6
13. Forward one-way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to
AT-17, "
Cross-sectional View" .)AT- 2 5 5
14. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-17,
"Cross-sectional View" .)AT- 2 5 5
33When you press the
accelerator pedal and
shift speed D3 → D2
or M
3 → M2 the
engine idles or the A/
T slips.ON vehicle1. A/T fluid level and stateAT- 4 9
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 1 0 8,
AT- 1 3 9
3. High and low reverse clutch solenoid valveAT- 1 5 1
4. Direct clutch solenoid valveAT- 1 4 9
5. CAN communication lineAT- 9 4
6. Line pressure testAT- 5 0
7. Control valve with TCMAT- 2 1 5
OFF vehicle8. Torque converterAT- 2 5 5
9. Oil pump assemblyAT- 2 7 1
10. 3rd one-way clutchAT- 2 7 4
11. Gear systemAT- 2 4 6
12. Direct clutchAT- 2 8 8
13. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-17,
"Cross-sectional View" .)AT- 2 5 5
No. Items Symptom Condition Diagnostic ItemReference
page