2007 INFINITI FX35 oil pressure

AT-38
A/T CONTROL SYSTEM
Revision: 2006 July 2007 FX35/FX45
Engine Brake ControlNCS001B5

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 ValveNCS001B6
FUNCTION OF CONTROL VALVE
SCIA1520E
Name Function
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 SYSTEM AT-39
D E
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G H
I
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K L
M A
B
AT
Revision: 2006 July 2007 FX35/FX45
FUNCTION OF ATF PRESSURE SWITCH
Input clutch control valve When 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 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 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
Name Function
ATF 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.
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.
ATF 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.
ATF 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.
ATF 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-54
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
8. Cool down the ATF.
CAUTION:
Run the engine at idle for at least 1 minute.
9. Repeat steps 5 through 8 with selector lever in “R” position.
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 A/T fluid temperature rises in range of 50 to 80 °C (122 to 176 °F) during 10 minutes of driving.
3. Remove the front propeller shaft from vehicle (with AWD models). Refer to PR-5, "
Removal and Installa-
tion" .
Selector lever position
Expected problem location
“D”, “M” “R”
Stall speed 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” 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

TROUBLE DIAGNOSIS AT-55
D E
F
G H
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K L
M A
B
AT
Revision: 2006 July 2007 FX35/FX45
4. 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.
5. Securely engage the parking brake so that the tires do not turn.
6. 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 3 , "
STALL TEST" .
7. After the measurements are complete, install the oil pressure detection plug and tighten to the specified torque.
CAUTION:

Do not reuse the O-ring.

Apply ATF to the O-ring.
Line Pressure
SCIA5309E
SCIA7463E
: 7.3 N·m (0.74 kg-m, 65 in-lb)SAT493G
Engine speed Line pressure kPa (kg/cm2 , psi)
“R” position “D” and “M” positions
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-56
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
Judgement of Line Pressure Test
ROAD TEST
Description

The road test checks 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 7
.
2. Check at idle. Refer to AT- 5 7
.
3. Cruise test

Inspect all the items from Part 1 to Part 3. Refer to AT- 5 8 , AT- 6 0 , AT- 6 1 .

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”,
“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 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 Line pressure does
not rise higher than
the line 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-72
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
23
Slips/Will
Not
Engage Vehicle cannot be
started from D
1 .
Refer to AT-201,
"Vehicle Cannot Be
Started From D1" . ON vehicle
1. A/T fluid level and state
AT- 5 3
2. Accelerator pedal position sensorAT- 1 3 1
3. Line pressure test AT- 5 4
4. CAN communication lineAT- 1 0 4
5. Control valve with TCMAT- 2 3 9
OFF vehicle 6. Torque converter
AT- 2 9 4
7. Oil pump assemblyAT- 3 1 2
8. 3rd one-way clutchAT- 3 1 5
9. 1st one-way clutch AT- 3 2 3
10. Gear systemAT- 2 7 4
11. Reverse brakeAT- 2 9 4
12. Forward one-way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to
AT-18, "
Cross-sectional View (2WD Models)" , AT- 1 9 ,
"Cross-sectional View (VQ35DE Models for AWD)" or AT-
20, "Cross-sectional View (VK45DE Models for AWD)" ) AT- 2 9 4
13. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-18,
"Cross-sectional View (2WD Models)" , AT-19, "Cross-sec-
tional View (VQ35DE Models for AWD)" or AT- 2 0 , "Cross-
sectional View (VK45DE Models for AWD)" ) AT- 2 9 4
24
Does not lock-up.
Refer to AT-213, "A/T
Does Not Lock-up" . ON vehicle 1. A/T fluid level and state
AT- 5 3
2. Line pressure testAT- 5 4
3. Engine speed signalAT- 1 2 3
4. Turbine revolution sensor AT- 11 6
5. Torque converter clutch solenoid valveAT- 1 2 5
6. CAN communication lineAT- 1 0 4
7. Control valve with TCMAT- 2 3 9
OFF vehicle 8. Torque converter
AT- 2 9 49. Oil pump assemblyAT- 3 1 2
25 Does not hold lock-up
condition.
Refer to AT-215, "A/T
Does Not Hold Lock-
up Condition" . ON vehicle 1. A/T fluid level and state
AT- 5 3
2. Line pressure testAT- 5 4
3. Engine speed signalAT- 1 2 3
4. Turbine revolution sensor AT- 11 6
5. Torque converter clutch solenoid valveAT- 1 2 5
6. CAN communication lineAT- 1 0 4
7. Control valve with TCMAT- 2 3 9
OFF vehicle 8. Torque converter
AT- 2 9 49. Oil pump assemblyAT- 3 1 2
No. Items Symptom Condition Diagnostic Item Reference
page

TROUBLE DIAGNOSIS AT-73
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AT
Revision: 2006 July 2007 FX35/FX4526
Slips/Will
Not
Engage Lock-up is not
released.
Refer to AT-217,
"Lock-up Is Not
Released" . ON vehicle 1. A/T fluid level and state
AT- 5 3
2. Line pressure testAT- 5 4
3. Engine speed signalAT-123
4. Turbine revolution sensor AT- 11 6
5. Torque converter clutch solenoid valveAT-125
6. CAN communication lineAT-104
7. Control valve with TCMAT-239
OFF vehicle 8. Torque converter
AT-2949. Oil pump assemblyAT-312
27 No shock at all or the
clutch slips when
vehicle changes
speed D
1 → D2 or
M
1 → M2 . ON vehicle
1. A/T fluid level and state
AT- 5 3
2. Vehicle speed sensor A/T and vehicle speed sensor MTR AT- 11 8,
AT-139
3. ATF pressure switch 5 and direct clutch solenoid valve AT-175,
AT-154
4. CAN communication line AT-104
5. Line pressure test AT- 5 4
6. Control valve with TCMAT-239
OFF vehicle 7. Torque converter
AT-294
8. Oil pump assemblyAT-312
9. 3rd one-way clutchAT-315
10. Gear systemAT-274
11. Direct clutchAT-332
12. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-18,
"Cross-sectional View (2WD Models)" , AT- 1 9 , "Cross-sec-
tional View (VQ35DE Models for AWD)" or AT-20, "Cross-
sectional View (VK45DE Models for AWD)" ) AT-294
No. Items Symptom Condition Diagnostic Item
Reference
page

AT-74
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
28
Slips/Will
Not
Engage No shock at all or the
clutch slips when
vehicle changes
speed D
2 → D3 or
M
2 → M3 . ON vehicle
1. A/T fluid level and state
AT- 5 3
2. Vehicle speed sensor A/T and vehicle speed sensor MTR AT- 11 8,
AT- 1 3 9
3. ATF pressure switch 6, high and low reverse clutch sole-
noid valve AT- 1 7 7,
AT- 1 5 8
4. CAN communication line AT- 1 0 4
5. Line pressure test AT- 5 4
6. Control valve with TCMAT- 2 3 9
OFF vehicle 7. Torque converter
AT- 2 9 4
8. Oil pump assemblyAT- 3 1 2
9. 3rd one-way clutchAT- 3 1 5
10. Gear systemAT- 2 7 4
11. High and low reverse clutchAT- 3 2 9
12. Forward one-way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to
AT-18, "
Cross-sectional View (2WD Models)" , AT- 1 9 ,
"Cross-sectional View (VQ35DE Models for AWD)" or AT-
20, "Cross-sectional View (VK45DE Models for AWD)" ) AT- 2 9 4
13. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-18,
"Cross-sectional View (2WD Models)" , AT-19, "Cross-sec-
tional View (VQ35DE Models for AWD)" or AT- 2 0 , "Cross-
sectional View (VK45DE Models for AWD)" ) AT- 2 9 4
29No shock at all or the
clutch slips when
vehicle changes
speed D
3 → D4 or
M
3 → M4 . ON vehicle
1. A/T fluid level and state
AT- 5 3
2. Vehicle speed sensor A/T and vehicle speed sensor MTR AT- 11 8,
AT- 1 3 9
3. ATF pressure switch 3 and input clutch solenoid valve AT- 1 7 3,
AT- 1 4 6

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