COMPONENT PARTSTM-223
< SYSTEM DESCRIPTION > [CVT: RE0F10E]
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NOTE:
• The principle of the linear solenoid valve utilizes the fa ct that the force pressing on the valve spool installed
inside the coil increases nearly in proportion to the current . This allows it to produce a fluid pressure that is
proportional to this pressing force.
• The N/H (normal high) produces hydraulic control when the coil is not energized.
CVT CONTROL SYSTEM : Se lect Solenoid ValveINFOID:0000000009464191
• The select solenoid valve is installed to control valve.
• The select solenoid valve adjusts the tightening pressure of the forward clutch and reverse brake. For infor-
mation about the forward clutch and reverse brake, refer to TM-229, "TRANSAXLE : Component Descrip-
tion".
• The select solenoid valve uses the linear solenoid valve [N/H (normal high) type]. NOTE:
• The principle of the linear solenoid valve utilizes the fa ct that the force pressing on the valve spool installed
inside the coil increases nearly in proportion to the current . This allows it to produce a fluid pressure that is
proportional to this pressing force.
• The N/H (normal high) type produces hydraulic control when the coil is not energized.
CVT CONTROL SYSTEM : Torque Converter Clutch Solenoid ValveINFOID:0000000009464192
• The torque converter clutch solenoid valve is installed to control valve.
• The torque converter clutch solenoid valve controls the torque converter clutch control valve. For information
about the torque converter clutch control valve, refer to TM-229, "TRANSAXLE : Component Description"
.
• The torque converter clutch solenoid valve utilizes a linear solenoid valve [N/L (normal low) type]. NOTE:
• The principle of the linear solenoid valve utilizes the fa ct that the force pressing on the valve spool installed
inside the coil increases nearly in proportion to the current . This allows it to produce a fluid pressure that is
proportional to this pressing force.
• The N/L (normal low) type does not produce hydraulic control when the coil is not energized.
CVT CONTROL SYSTEM : Line Pressure Solenoid ValveINFOID:0000000009464193
• The line pressure solenoid valve is installed to control valve.
• The line pressure solenoid valve controls the pressu re regulator valve. For information about the pressure
regulator valve, refer to TM-229, "TRANSAXLE : Component Description"
.
• The line pressure solenoid valve uses the linear solenoid valve [N/H (normal high) type]. NOTE:
• The principle of the linear solenoid valve utilizes the fa ct that the force pressing on the valve spool installed
inside the coil increases nearly in proportion to the current . This allows it to produce a fluid pressure that is
proportional to this pressing force.
• The N/H (normal high) produces hydraulic control when the coil is not energized.
CVT CONTROL SYSTEM : Paddle ShifterINFOID:0000000009464194
• The paddle shifter is installed to the steering.
• The paddle shifter transmits shift up and shift down switch signals to the combination meter. Then TCM
receives signals from the combination meter via CAN communication.
PADDLE SHIFTER FUNCTION
CVT CONTROL SYSTEM : Sh ift Position IndicatorINFOID:0000000009464195
TCM transmits shift position signal to combination mete r via CAN communication. The actual shift position is
displayed on combination meter according to the signal.
SHIFT LOCK SYSTEM
Selector lever po-
sition Function
D Although driving in manual mode is possible, selector lever automatically returns to D position after a certain period
of time because the selector lever is not fixed in manual mode.
DS Driving with the selector lever fixed in manual mode is possible.
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
STRUCTURE AND OPERATIONTM-225
< SYSTEM DESCRIPTION > [CVT: RE0F10E]
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STRUCTURE AND OPERATION
TRANSAXLE
TRANSAXLE : Cross-Sectional ViewINFOID:0000000009464197
Converter housing Oil pump Planetary gear
Control valve Oil pan Chain belt
Primary pulley Secondary pulley Side cover
Transaxle case Differential case Final gear
Reduction gear Idler gear Output gear
Drive sprocket Torque converter Driven sprocket
Oil pump chain
JSDIA3719ZZ
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
TM-226
< SYSTEM DESCRIPTION >[CVT: RE0F10E]
STRUCTURE AND OPERATION
TRANSAXLE : Operation Status
INFOID:0000000009464198
× : Engaged or applied.
TRANSAXLE : Trans axle MechanismINFOID:0000000009464199
TORQUE CONVERTER (WITH LOCK-UP FUNCTION)
In the same way as a conventional A/T, the torque c onverter is a system that increases the engine torque and
transmits the torque to the transaxle. A symmetr ical 3-element, 1-stage, 2-phase type is used here.
OIL PUMP
Utilizes a vane-type oil pump that is driven by the engi ne through the oil pump drive chain in order to increase
efficiency of pump discharge volume in low-speed zone and optimize pump discharge volume in high-speed
zone. Discharged oil from oil pump is transmitted to contro l valve. It is used as the oil of primary and second-
ary pulley operation, the oil of clutch operation, and the lubricant for each part.
PLANETARY GEAR
• A planetary gear type of forward/reverse selector me chanism is installed between the torque converter and
primary pulley.
• The power from the torque converter is input via the i nput shaft, operating a wet multi-plate clutch by means
of hydraulic pressure to switch between forward and reverse driving.
Operation of Planetary gear
BELT & PULLEY
It is composed of a pair of pulleys (the groove width is changed freely in the axial direction) and the chain belt
.The groove width changes according to wrapping radius of chain belt and pulley from low status to overdrive
status continuously with non-step. It is controlled wit h the oil pressures of primary pulley and secondary pulley.
Chain belt
Selector lever
position Parking mech-
anism Forward
clutch Reverse brake Primary pulley Secondary
pulley Chain belt Final drive
P ×
R ×××××
N
D × ××××
DS × ××××
JSDIA2426GB
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
STRUCTURE AND OPERATIONTM-229
< SYSTEM DESCRIPTION > [CVT: RE0F10E]
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TRANSAXLE : Component DescriptionINFOID:0000000009464201
FLUID COOLER & FLUID WARMER SYSTEM
Part name Function
Torque converter Increases engine torque and transmits it to the transaxle.
Oil pump Utilizes a vane-type oil pump that is driven by the engine through the oil pump drive chain in order to
increase efficiency of pump discharge volume in low-speed zone and optimize pump discharge volume
in high-speed zone. Discharged oil from oil pump is tr ansmitted to control valve. It is used as the oil of
primary and secondary pulley operation, the oil of clutch operation, and the lubricant for each part.
Forward clutch The forward clutch is wet and multiple plate type clutch that consists of clutch drum, piston, drive plate,
and driven plate. It is a clutch to move the vehicle forward by activating piston hydraulically, engaging
plates, and directly connecting sun gear and input shaft.
Reverse brake The reverse brake is a wet multiple-plate type brake that consists of transaxle case, piston, drive plate,
and driven plate. It is a brake to move the vehicle in reverse by activating piston hydraulically, engaging
plates, and fixing planetary gear.
Internal gear The internal gear is directly connected to forward clutch drum. It is a gear that moves the outer edge of
pinion planet of planet carrier. It transmits power to move the vehicle in reverse when the planet carrier
is fixed.
Planet carrier Composed of a carrier, pinion planet, and pinion shaft. This gear fixes and releases the planet carrier in
order to switch between forward and reverse driving.
Sun gear Sun gear is a set part with planet carrier and internal gear. It transmits transmitted force to primary fixed
sheave. It rotates in forward or reverse direction according to activation of either forward clutch or re-
verse brake.
Input shaft The input shaft is directly connected to forward clutch drum and transmits traction force from torque con-
verter. In shaft center, there are holes for hydraulic distribution to primary pulley and hydraulic distribution
for lockup ON/OFF.
Primary pulley It is composed of a pair of pulleys (the groove width is changed freely in the axial direction) and the chain belt. The groove width changes according to wrapping radius of steel belt and pulley from low status to
overdrive status continuously with non-step. It is controlled with the oil pressures of primary pulley and
secondary pulley.
Secondary pulley
Chain belt
Manual shaft When the manual shaft is in the P position, the parking rod that is linked to the manual shaft rotates the
parking pole. When the parking pole rotates, it engages with the parking gear, fixing the parking gear. As
a result, the secondary pulley that is integrated with the parking gear is fixed.
Parking rod
Parking pawl
Parking gear
Output gear
The deceleration gears are composed of 2 stages: primary deceleration (output gear, idler gear pair) and
secondary deceleration (reduction gear, final gear pair). All of these gears are helical gears.
Idler gear
Reduction gear
Differential
Torque converter regulator
valve Adjusts the feed pressure to the torque converter to the optimum pressure corresponding to the driving
condition.
Pressure regulator valve Adjusts the discharge pressure from the oil pump to the optimum pressure (line pressure) corresponding
to the driving condition.
Torque converter clutch
control valve Adjusts the torque converter engage and disengage pressures.
Manual valve Distributes the clutch operation pressure to each circuit according to the selector lever position.
Secondary reducing valve Reduces line pressure and adjusts secondary pressure.
Primary reducing valve Reduces line pressure and adjusts primary pressure.
Pilot valve A Reduces line pressure and adjusts pilot pressure to the solenoid valves listed below.
• Primary pressure solenoid valve
• Secondary pressure solenoid valve
• Select solenoid valve
• Line pressure solenoid valve
Pilot valve B Reduces pilot pressure and adjusts pilot pressure to the torque converter clutch solenoid valve.
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
SYSTEMTM-233
< SYSTEM DESCRIPTION > [CVT: RE0F10E]
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• CVT detects the vehicle driving status from switc hes, sensors and signals, and controls the vehicle so that
the optimum shift position and shift timing may always be achieved. It also controls the vehicle to reduce
shift and lockup shock, etc.
• Receives input signals from switches and sensors.
• Sends the output signal necessary for operation of so lenoid valves, and evaluates the line pressure, shift
timing, lockup operation, engine brake performance, etc.
• If a malfunction occurs on the electric system, activa te the fail-safe mode only to drive the vehicle.
LIST OF CONTROL ITEMS AND INPUT/OUTPUT
*: If these input/output signals show errors, TCM activates the fail-safe function.
CVT CONTROL SYSTEM : Fail-safeINFOID:0000000009464205
TCM has a fail-safe mode. The mode functions so that operation can be continued even if the signal circuit of
the main electronically controlled input/output parts is damaged.
If the vehicle shows following behaviors including “poor acceleration”, a malfunction of the applicable system
is detected by TCM and the vehicle may be in a fail-s afe mode. At this time, check the DTC code and perform
inspection and repair according to the malfunction diagnosis procedures.
Fail-safe function
Control Item Shift control Line pressure
control Select control Lock-up con-
trol Fail-safe func-
tion*
Input Engine torque signal
(CAN communication) ×××××
Engine speed signal
(CAN communication) ×××××
Accelerator pedal position signal
(CAN communication) ××××
Closed throttle position signal
(CAN communication) ×× ×
Stop lamp switch signal
(CAN communication) ××××
Primary pressure sensor ×
Secondary pressure sensor ×× ×
CVT fluid temperature sensor ×××××
Primary speed sensor ×××××
Output speed sensor ×× ××
Input speed sensor ×××××
Transmission range switch ×××××
Paddle shifter
(CAN communication) ×× ×
Output Line pressure solenoid valve
××× ×
Primary pressure solenoid valve ×× ×
Torque converter clutch solenoid
valve ××
Secondary pressure solenoid valve ×× ×
Select solenoid valve ×××
Shift position indicator
(CAN communication) ×
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
TM-236
< SYSTEM DESCRIPTION >[CVT: RE0F10E]
SYSTEM
CVT CONTROL SYSTEM : Protection Control
INFOID:0000000009464206
The TCM becomes the protection control status temporar ily to protect the safety when the safety of TCM and
transmission is lost. It automatically returns to the normal status if the safety is secured.
The TCM has the following protection control.
CONTROL FOR WHEEL SPIN
TORQUE IS REDUCED WHEN DRIVING WITH THE REVERSE GEAR
CONTROL WHEN FLUID TEMPERATURE IS HIGH
P2813 • Selector shock is large
•Start is slow
• Acceleration is slow
• Vehicle speed is not increased When a malfunction occurs on the low oil pressure side
• Selector shock is large When a malfunction occurs on the high oil pressure side
P2814 • Selector shock is large —
P2815 • Selector shock is large —
U0073 • Selector shock is large
•Start is slow
• Acceleration is slow
• Lock-up is not performed —
U0100 • Selector shock is large
•Start is slow
• Acceleration is slow
• Lock-up is not performed —
U0140 • Not changed from normal driving —
U0141 • Not changed from normal driving —
U0155 • Not changed from normal driving —
U0300 • Selector shock is large
•Start is slow
• Acceleration is slow
• Lock-up is not performed —
U1000 • Not changed from normal driving — U1117 • Not changed from normal driving — DTC Vehicle behavior Conditions of vehicle
Control
When a wheel spin is detected, the engine output and gear ratio are limited and the line pressure is increased.
Limits engine output when a wheel spin occurs in any of right and left drive wheels.
Vehicle behavior in
control If the accelerator is kept depressing during wheel spin, the engine revolution and vehicle speed are limited to
a certain degree.
Normal retu rn condi-
tion Wheel spin convergence returns the control to the normal control.
Control Engine output is controlled according to a vehicle speed while reversing the vehicle.
Vehicle behavior in
control Power performance may be lowered while reversing the vehicle.
Normal retu rn condi-
tion Torque returns to normal by positioning the selector lever in a range other than “R” position.
Control
When the CVT fluid temperature is high, the gear shift permission maximum revolution and the maximum
torque are reduced than usual to prevent increase of the oil temperature.
Vehicle behavior in
control Power performance may be lowered, compared to normal control.
Normal retu rn condi-
tion The control returns to the normal control when CVT fluid temperature is lowered.
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
SYSTEMTM-237
< SYSTEM DESCRIPTION > [CVT: RE0F10E]
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REVERSE PROHIBIT CONTROL
LINE PRESSURE CONTROL
LINE PRESSURE CONTROL : System DescriptionINFOID:0000000009464207
SYSTEM DIAGRAM
DESCRIPTION
Highly accurate line pressure control (secondary pressure control) reduces friction for improvement of fuel
economy.
Normal Oil Pressure Control
Appropriate line pressure and secondary pressure suitable for driving condition are determined based on the
accelerator pedal position, engine speed, primary pulley (input) speed, secondary pulley (output) speed, vehi-
cle speed, input torque, stop lamp switch signal, transmission range switch signal, lock-up signal, power volt-
age, target shift ratio, oil temperature, oil pressure, and paddle shift (up/down) signal.
Secondary Pressure Feedback Control
In normal oil pressure control and oil pressure control in shifting, highly accurate secondary pressure is deter-
mined by detecting the secondary pressure using an oil pressure sensor and by feedback control.
SHIFT CONTROL
Control The reverse brake is controlled to avoid becoming engaged when the selector lever is set in “R” position while
driving in forward direction at more than the specified speed.
Vehicle behavior in
control If the selector lever is put at “R” position when driving with the forward gear, the gear becomes neutral, not
reverse.
Normal return condi-
tion The control returns to normal control when the vehicle is driven at low speeds. (The reverse brake becomes
engaged.)
JSDIA3716GB
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
SYSTEMTM-241
< SYSTEM DESCRIPTION > [CVT: RE0F10E]
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DESCRIPTION
• Controls for improvement of the transmission effici ency by engaging the torque converter clutch in the
torque converter and eliminating slip of the converter. Achieves comfortable driving with slip control of the
torque converter clutch.
• The oil pressure feed circuit for the torque converter clutch piston chamber is connected to the torque con-
verter clutch control valve. The torque converter clut ch control valve is switched by the torque converter
clutch solenoid valve with the signal from TCM. This contro ls the oil pressure circuit, which is supplied to the
torque converter clutch piston chamber, to the release side or engagement side.
• If the CVT fluid temperature is low or the vehicle is in fail-safe mode due to malfunction, lock-up control is
prohibited.
Lock-up engagement
In lock-up engagement, the torque converter clutch solenoi d valve makes the torque converter clutch control
valve locked up to generate the lock-up apply pressure. This pushes the torque converter clutch piston for
engagement.
Lock-up release condition
In lock-up release, the torque converter clutch solenoi d valve makes the torque converter clutch control valve
non-locked up to drain the lock-up apply pressure. This does not engage the torque converter clutch piston.
JSDIA3717GB
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM