torque INFINITI FX35 2005 Service Manual

AT-2Revision: 2005 July 2005 FX
Possible Cause ....................................................
.114
DTC Confirmation Procedure .............................. .114
Wiring Diagram — AT — PNP/SW ...................... .115
Diagnostic Procedure .......................................... .116
DTC P0720 VEHICLE SPEED SENSOR A/T (REV-
OLUTION SENSOR) .............................................. .118
Description ........................................................... .118
CONSULT-II Reference Value ............................. .118
On Board Diagnosis Logic ................................... .118
Possible Cause .................................................... .118
DTC Confirmation Procedure .............................. .118
Wiring Diagram — AT — VSSA/T ........................ .120
Diagnostic Procedure .......................................... .121
DTC P0725 ENGINE SPEED SIGNAL .................. .123
Description ........................................................... .123
CONSULT-II Reference Value ............................. .123
On Board Diagnosis Logic ................................... .123
Possible Cause .................................................... .123
DTC Confirmation Procedure .............................. .123
Diagnostic Procedure .......................................... .124
DTC P0740 TORQUE CONVERTER CLUTCH
SOLENOID VALVE ................................................ .125
Description ........................................................... .125
CONSULT-II Reference Value ............................. .125
On Board Diagnosis Logic ................................... .125
Possible Cause .................................................... .125
DTC Confirmation Procedure .............................. .125
Diagnostic Procedure .......................................... .126
DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP) .127
Description ........................................................... .127
CONSULT-II Reference Value ............................. .127
On Board Diagnosis Logic ................................... .127
Possible Cause .................................................... .127
DTC Confirmation Procedure .............................. .127
Diagnostic Procedure .......................................... .128
DTC P0745 LINE PRESSURE SOLENOID VALVE .129
Description ........................................................... .129
CONSULT-II Reference Value ............................. .129
On Board Diagnosis Logic ................................... .129
Possible Cause .................................................... .129
DTC Confirmation Procedure .............................. .129
Diagnostic Procedure .......................................... .130
DTC P1702 TRANSMISSION CONTROL MODULE
(RAM) ..................................................................... .131
Description ........................................................... .131
On Board Diagnosis Logic ................................... .131
Possible Cause .................................................... .131
DTC Confirmation Procedure .............................. .131
Diagnostic Procedure .......................................... .131
DTC P1703 TRANSMISSION CONTROL MODULE
(ROM) ..................................................................... .132
Description ........................................................... .132
On Board Diagnosis Logic ................................... .132
Possible Cause .................................................... .132
DTC Confirmation Procedure .............................. .132
Diagnostic Procedure .......................................... .132
DTC P1705 THROTTLE POSITION SENSOR ...... .133
Description ........................................................... .133
CONSULT-II Reference Value ............................. .133 On Board Diagnosis Logic ...................................
.133
Possible Cause .................................................... .133
DTC Confirmation Procedure ............................... .133
Diagnostic Procedure ........................................... .134
DTC P1710 A/T FLUID TEMPERATURE SENSOR
CIRCUIT ................................................................. .136
Description ........................................................... .136
CONSULT-II Reference Value .............................. .136
On Board Diagnosis Logic ................................... .136
Possible Cause .................................................... .136
DTC Confirmation Procedure ............................... .136
Wiring Diagram — AT — FTS .............................. .137
Diagnostic Procedure ........................................... .138
Component Inspection ......................................... .140
DTC P1716 TURBINE REVOLUTION SENSOR ... .141
Description ........................................................... .141
CONSULT-II Reference Value .............................. .141
On Board Diagnosis Logic ................................... .141
Possible Cause .................................................... .141
DTC Confirmation Procedure ............................... .141
Diagnostic Procedure ........................................... .142
DTC P1721 VEHICLE SPEED SENSOR MTR ...... .143
Description ........................................................... .143
CONSULT-II Reference Value .............................. .143
On Board Diagnosis Logic ................................... .143
Possible Cause .................................................... .143
DTC Confirmation Procedure ............................... .143
Diagnostic Procedure ........................................... .144
DTC P1730 A/T INTERLOCK ................................ .145
Description ........................................................... .145
On Board Diagnosis Logic ................................... .145
Possible Cause .................................................... .145
DTC Confirmation Procedure ............................... .145
Judgement of A/T Interlock .................................. .145
Diagnostic Procedure ........................................... .146
DTC P1731 A/T 1ST ENGINE BRAKING .............. .148
Description ........................................................... .148
CONSULT-II Reference Value .............................. .148
On Board Diagnosis Logic ................................... .148
Possible Cause .................................................... .148
DTC Confirmation Procedure ............................... .148
Diagnostic Procedure ........................................... .149
DTC P1752 INPUT CLUTCH SOLENOID VALVE . .150
Description ........................................................... .150
CONSULT-II Reference Value .............................. .150
On Board Diagnosis Logic ................................... .150
Possible Cause .................................................... .150
DTC Confirmation Procedure ............................... .150
Diagnostic Procedure ........................................... .151
DTC P1754 INPUT CLUTCH SOLENOID VALVE
FUNCTION ............................................................. .152
Description ........................................................... .152
CONSULT-II Reference Value .............................. .152
On Board Diagnosis Logic ................................... .152
Possible Cause .................................................... .152
DTC Confirmation Procedure ............................... .152
Diagnostic Procedure ........................................... .153
DTC P1757 FRONT BRAKE SOLENOID VALVE .. .154
Description ........................................................... .154

AT-8
PRECAUTIONS
Revision: 2005 July 2005 FX
Precautions ACS002L6

Before connecting or disconnecting the A/T assembly har-
ness connector, turn ignition switch OFF and disconnect
the battery cable from the negative terminal. Because bat-
tery voltage is applied to TCM even if ignition switch is
turned OFF.

After performing each TROUBLE DIAGNOSIS, perform
“DTC (Diagnostic Trouble Code) Confirmation Procedure”.
If the repair is completed the DTC should not be displayed
in the “DTC Confirmation Procedure”.

Always use the specified brand of ATF. Refer to MA-12, "Fluids and Lubricants" .

Use lint-free paper not cloth rags during work.

After replacing the ATF, dispose of the waste oil using the methods prescribed by law, ordinance, etc.

Before proceeding with disassembly, thoroughly clean the outside of the transmission. It is important to
prevent the internal parts from becoming contaminated by dirt or other foreign matter.

Disassembly should be done in a clean work area.

Use lint-free paper or towels for wiping parts clean. Common shop rags can leave fibers that could inter-
fere with the operation of the transmission.

Place disassembled parts in order for easier and proper assembly.

All parts should be carefully cleansed with a general purpose, non-flammable solvent before inspection or
reassembly.

Gaskets, seals and O-rings should be replaced any time the transmission is disassembled.

It is very important to perform functional tests whenever they are indicated.

The valve body contains precision parts and requires extreme care when parts are removed and serviced.
Place disassembled valve body parts in order for easier and proper assembly. Care will also prevent
springs and small parts from becoming scattered or lost.

Properly installed valves, sleeves, plugs, etc. will slide along bores in valve body under their own weight.

Before assembly, apply a coat of recommended ATF to all parts. Apply petroleum jelly to protect O-rings
and seals, or hold bearings and washers in place during assembly. Do not use grease.

Extreme care should be taken to avoid damage to O-rings, seals and gaskets when assembling.

After overhaul, refill the transmission with new ATF.

When the A/T drain plug is removed, only some of the ATF is drained. Old ATF will remain in torque con-
verter and ATF cooling system.
Always follow the procedures under “Changing A/T Fluid” in the AT section when changing A/T fluid. Refer
to AT- 1 2 , "
Changing A/T Fluid" , AT- 1 3 , "Checking A/T Fluid" .
SEF289H
SEF217U

AT-18
A/T CONTROL SYSTEM
Revision: 2005 July 2005 FX
A/T CONTROL SYSTEMPFP:31036
Cross-Sectional View (2WD Models)ACS002LD
1. Front planetary gear 2. Mid planetary gear 3. Rear planetary gear
4. Direct clutch 5. High and low reverse clutch 6. Reverse brake
7. Drum support 8. Forward brake 9. Low coast brake
10. Input shaft 11. Torque converter 12. Oil pump
13. Front brake 14. 3rd one-way clutch 15. Input clutch
16. 1st one-way clutch 17. Control valve with TCM 18. Forward one-way clutch
19. Rear extension 20. Output shaft
SCIA5262E

A/T CONTROL SYSTEM AT-19
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M A
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AT
Revision: 2005 July 2005 FX
Cross-Sectional View (AWD Models)ACS0033B
1. Front planetary gear 2. Mid planetary gear 3. Rear planetary gear
4. Direct clutch 5. High and low reverse clutch 6. Reverse brake
7. Drum support 8. Forward brake 9. Low coast brake
10. Input shaft 11. Torque converter 12. Oil pump
13. Front brake 14. 3rd one-way clutch 15. Input clutch
16. 1st one-way clutch 17. Control valve with TCM 18. Forward one-way clutch
19. Adapter case 20. Output shaft
SCIA5263E

AT-22
A/T CONTROL SYSTEM
Revision: 2005 July 2005 FX
POWER TRANSMISSION
“N” Position
Since both the forward brake and the reverse brake are released, torque from the input shaft drive is not trans-
mitted to the output shaft.
“P” Position

The same as for the “N” position, both the forward brake and the reverse brake are released, so torque
from the input shaft drive is not transmitted to the output shaft.

The parking pawl linked with the selector lever meshes with the parking gear and fastens the output shaft
mechanically.
1. Front brake 2. Input clutch 3. Direct clutch
4. High and low reverse clutch 5. Reverse brake 6. Forward brake
7. Low coast brake 8. 1st one-way clutch 9. Forward one-way clutch
10. 3rd one-way clutch 11. Front sun gear 12. Input shaft
13. Mid internal gear 14. Front internal gear 15. Rear carrier
16. Rear sun gear 17. Mid sun gear 18. Front carrier
19. Mid carrier 20. Rear internal gear 21. Output shaft
22. Parking gear 23. Parking pawl
PCIA0003J

A/T CONTROL SYSTEM AT-31
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M A
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AT
Revision: 2005 July 2005 FX
TCM FunctionACS002LF
The function of the TCM is to:

Receive input signals sent from various switches and sensors.

Determine required line pressure, shifting point, lock-up operation, and engine brake operation.

Send required output signals to the respective solenoids.
CONTROL SYSTEM OUTLINE
The automatic transmission senses vehicle operating conditions through various sensors or signals. It always
controls the optimum shift position and reduces shifting and lock-up shocks.
CONTROL SYSTEM DIAGRAM
SENSORS (or SIGNALS)

TCM

ACTUATORS
PNP switch
Accelerator pedal position signal
Closed throttle position signal
Wide open throttle position signal
Engine speed signal
A/T fluid temperature sensor
Revolution sensor
Vehicle speed signal
Manual mode switch signal
Stop lamp switch signal
Turbine revolution sensor
ATF pressure switch Shift control
Line pressure control
Lock-up control
Engine brake control
Timing control
Fail-safe control
Self-diagnosis
CONSULT-II communication line
Duet-EA control
CAN system Input clutch solenoid valve
Direct clutch solenoid valve
Front brake solenoid valve
High and low reverse clutch
solenoid valve
Low coast brake solenoid valve
Torque converter clutch solenoid
valve
Line pressure solenoid valve
A/T CHECK indicator lamp
Sta r te r re l a y
Back-up lamp relay
SCIA5325E

A/T CONTROL SYSTEM AT-33
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Revision: 2005 July 2005 FX
Line Pressure ControlACS002LI

When an input torque signal equivalent to the engine drive force is sent from the ECM to the TCM, the
TCM controls the line pressure solenoid.

This line pressure solenoid controls the pressure regulator valve as the signal pressure and adjusts the
pressure of the operating oil discharged from the oil pump to the line pressure most appropriate to the
driving state.
LINE PRESSURE CONTROL IS BASED ON THE TCM LINE PRESSURE CHARACTERISTIC
PATTERN

The TCM has stored in memory a number of patterns for the optimum line pressure characteristic for the
driving state.

In order to obtain the most appropriate line pressure characteristic to meet the current driving state, the
TCM controls the line pressure solenoid current valve and thus controls the line pressure.
Normal Control
Each clutch is adjusted to the necessary pressure to match the
engine drive force.
Back-Up Control (Engine Brake)
When the select operation is performed during driving and the trans-
mission is shifted down, the line pressure is set according to the
vehicle speed.
PCIA0007E
PCIA0008E
PCIA0009E

AT-34
A/T CONTROL SYSTEM
Revision: 2005 July 2005 FX
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 ControlACS002LJ
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.
PCIA0010E
PCIA0011E
PCIA0012E

A/T CONTROL SYSTEM AT-35
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AT
Revision: 2005 July 2005 FX
SHIFT CHANGE
The clutch is controlled with the optimum timing and oil pressure by the engine speed, engine torque informa-
tion, etc.
Shift Change System Diagram
*1: Full phase real-time feedback control monitors movement of gear ratio at gear change, and controls oil
pressure at real-time to achieve the best gear ratio.
Lock-up ControlACS002LK
The torque converter clutch piston in the torque converter is engaged to eliminate torque converter slip to
increase power transmission efficiency.
The torque converter clutch control valve operation is controlled by the torque converter clutch solenoid valve,
which is controlled by a signal from TCM, and the torque converter clutch control valve engages or releases
the torque converter clutch piston.
Lock-up Operation Condition Table
TORQUE CONVERTER CLUTCH CONTROL VALVE CONTROL
Lock-up Control System Diagram
PCIA0013E
selector lever D position M5 position M4 position
Gear position 5 4 5 4
Lock-up ×– ××
Slip lock-up ××––
PCIA0014E

AT-36
A/T CONTROL SYSTEM
Revision: 2005 July 2005 FX
Lock-up Released

In the lock-up released state, the torque converter clutch control valve is set into the unlocked state by the
torque converter clutch solenoid and the lock-up apply pressure is drained.
In this way, the torque converter clutch piston is not coupled.
Lock-up Applied

In the lock-up applied state, the torque converter clutch control valve is set into the locked state by the
torque converter clutch solenoid and lock-up apply pressure is generated.
In this way, the torque converter clutch piston is pressed and coupled.
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 cou-
pling 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 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.
SCIA1520E