2004 INFINITI FX35 oil pressure

AT-36
A/T CONTROL SYSTEM
Revision: 2004 November 2004 FX35/FX45
Engine Brake ControlACS002LL

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 ValveACS002LM
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.)

A/T CONTROL SYSTEM
AT-37
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: 2004 November 2004 FX35/FX45
FUNCTION OF ATF 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 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 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 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 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-52
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
CAUTION:
Run the engine at idle for at least one minute.
Judgement 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 A/T fluid reaches in range of 50 to 80°C (122
to 176°F), then inspect the amount of A/T fluid 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 front propeller shaft from vehicle (with AWD models). Refer to PR-4, "
Removal and Installation" . Stall speed:
VQ35DE engine: 2,650 - 2,950 rpm
VK45DE engine: 2,300 - 2,600 rpm
Selector lever position
Expected problem location
D, 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, M position 1 → 2 Slipping in 2nd, 3rd, 4th gears Direct clutch slippage
Does not shift up D, M position 2 → 3 Slipping in 3rd, 4th, 5th gears high and low reverse clutch slippage
Does not shift up D, M position 3 → 4 Slipping in 4th, 5th gears Input clutch slippage
Does not shift up D, M position 4 → 5 Slipping in 5th gear Front brake slippage
SCIA2187E

TROUBLE DIAGNOSIS
AT-53
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: 2004 November 2004 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 1 , "
STALL TEST" .
7. 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 speedLine pressure [kPa (kg/cm
2 , psi)]
R position D, M positions
At idle speed 392 - 441 (4.0 - 4.5, 57 - 64) 373 - 422 (3.8 - 4.3, 54 - 61)
At stall speed 1,700 - 1,890 (17.3 - 19.3, 247 - 274) 1,310 - 1,500 (13.3 - 15.3, 190 - 218)

AT-54
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
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 7 , 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
complete.
Judgement 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 spe-
cific 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 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 speedOil 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 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.

TROUBLE DIAGNOSIS
AT-73
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: 2004 November 2004 FX35/FX45
23
Slips/Will
Not
EngageVehicle cannot be
started from D
1 .
Refer to AT-203,
"Vehicle Cannot Be
Started From D1" .ON vehicle1. Fluid level and stateAT- 5 1
2. Accelerator pedal position sensorAT-136
3. Line pressure testAT- 5 2
4. CAN communication lineAT-105
5. Control valve with TCMAT-242
OFF vehicle6. Torque converterAT-286
7. Oil pump assemblyAT-303
8. 3rd one-way clutchAT-306
9. 1st one-way clutch AT-314
10. Gear systemAT-274
11. Reverse brakeAT-286
12. Forward one-way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to
AT- 1 7 , "
Cross-Sectional View (2WD Models)" or AT- 1 8 ,
"Cross-Sectional View (AWD Models)" )AT-286
13. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-17,
"Cross-Sectional View (2WD Models)" or AT-18, "Cross-
Sectional View (AWD Models)" )AT-286
24Does not lock-up.
Refer to AT-216, "A/T
Does Not Perform
Lock-up" .ON vehicle1. Fluid level and stateAT- 5 1
2. Line pressure testAT- 5 2
3. Engine speed signalAT-121
4. Turbine revolution sensorAT-143
5. Torque converter clutch solenoid valveAT-123
6. CAN communication lineAT-105
7. Control valve with TCMAT-242
OFF vehicle8. Torque converterAT-2869. Oil pump assemblyAT-303
25Does not hold lock-up
condition.
Refer to AT-218, "A/T
Does Not Hold Lock-
up Condition" .ON vehicle1. Fluid level and stateAT- 5 1
2. Line pressure testAT- 5 2
3. Engine speed signalAT-121
4. Turbine revolution sensorAT-143
5. Torque converter clutch solenoid valveAT-123
6. CAN communication lineAT-105
7. Control valve with TCMAT-242
OFF vehicle8. Torque converterAT-2869. Oil pump assemblyAT-303
No. Items Symptom Condition Diagnostic ItemReference
page

AT-74
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
26
Slips/Will
Not
engageLock-up is not
released.
Refer to AT-220,
"Lock-up Is Not
Released" .ON vehicle1. Fluid level and stateAT- 5 1
2. Line pressure testAT- 5 2
3. Engine speed signalAT- 1 2 1
4. Turbine revolution sensorAT- 1 4 3
5. Torque converter clutch solenoid valveAT- 1 2 3
6. CAN communication lineAT- 1 0 5
7. Control valve with TCMAT- 2 4 2
OFF vehicle8. Torque converterAT- 2 8 69. Oil pump assemblyAT- 3 0 3
27No shock at all or the
clutch slips when
vehicle changes
speed D
1 → D2 or
M
1 → M2 . ON vehicle1. Fluid level and stateAT- 5 1
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 6,
AT- 1 4 5
3. ATF pressure switch 5 and direct clutch solenoid valveAT- 1 8 2,
AT- 1 6 0
4. CAN communication lineAT- 1 0 5
5. Line pressure testAT- 5 2
6. Control valve with TCMAT- 2 4 2
OFF vehicle7. Torque converterAT- 2 8 6
8. Oil pump assemblyAT- 3 0 3
9. 3rd one-way clutchAT- 3 0 6
10. Gear systemAT- 2 7 4
11. Direct clutchAT- 3 2 3
12. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-17,
"Cross-Sectional View (2WD Models)" or AT- 1 8 , "Cross-
Sectional View (AWD Models)" )AT- 2 8 6
No. Items Symptom Condition Diagnostic ItemReference
page

TROUBLE DIAGNOSIS
AT-75
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: 2004 November 2004 FX35/FX45
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. Fluid level and stateAT- 5 1
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 6,
AT-145
3. ATF pressure switch 6, high and low reverse clutch sole-
noid valveAT-184,
AT-164
4. CAN communication lineAT-105
5. Line pressure testAT- 5 2
6. Control valve with TCMAT-242
OFF vehicle7. Torque converterAT-286
8. Oil pump assemblyAT-303
9. 3rd one-way clutchAT-306
10. Gear systemAT-274
11. High and low reverse clutchAT-320
12. Forward one-way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to
AT- 1 7 , "
Cross-Sectional View (2WD Models)" or AT- 1 8 ,
"Cross-Sectional View (AWD Models)" )AT-286
13. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-17,
"Cross-Sectional View (2WD Models)" or AT-18, "Cross-
Sectional View (AWD Models)" )AT-286
29No shock at all or the
clutch slips when
vehicle changes
speed D
3 → D4 or
M
3 → M4 .ON vehicle1. Fluid level and stateAT- 5 1
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 6,
AT-145
3. ATF pressure switch 3 and input clutch solenoid valveAT-180,
AT-152

4. ATF pressure switch 1 and front brake solenoid valveAT-178
,
AT-156
5. CAN communication lineAT-105
6. Line pressure testAT- 5 2
7. Control valve with TCMAT-242
OFF vehicle8. Torque converterAT-286
9. Oil pump assemblyAT-303
10. Input clutchAT-308
11. Gear systemAT-274
12. High and low reverse clutchAT-320
13. Direct clutchAT-323
No. Items Symptom Condition Diagnostic ItemReference
page