COMPONENT PARTSTM-19
< SYSTEM DESCRIPTION > [CVT: RE0F10D]
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• When pressure is applied to the metal diaphragm in the secondary pressure sensor, the metal diaphragm is deformed, resulting in voltage change. TCM evaluates the secondary pressure from its voltage change. Volt-
age is increased along with pressure increase.
CVT CONTROL SYSTEM : Primar y Pressure Solenoid ValveINFOID:0000000009463971
• The primary pressure solenoid valve is installed to control valve.
• The primary pressure solenoid valve controls the pr imary reducing valve. For information about the primary
reducing valve, refer to TM-27, "TRANSAXLE : Component Description"
.
• The primary 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 : Secondar y Pressure Solenoid ValveINFOID:0000000009463972
• The secondary pressure solenoid valve is installed to control valve.
• The secondary pressure solenoid valve controls the secondary reducing valve. For information about the
secondary reducing valve, refer to TM-27, "TRANSAXLE : Component Description"
.
• The secondary 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 : Se lect Solenoid ValveINFOID:0000000009463973
• 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-27, "TRANSAXLE : Component Description"
.
• 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:0000000009463974
• 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-27, "TRANSAXLE : Component Description"
.
• The torque converter clutch solenoid valve utilizes a linear solenoid valve [N/L (normal low) type].
NOTE:
JSDIA1831GB
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
TM-20
< SYSTEM DESCRIPTION >[CVT: RE0F10D]
COMPONENT PARTS
• 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 hydr aulic control when the coil is not energized.
CVT CONTROL SYSTEM : Line Pressure Solenoid ValveINFOID:0000000009463975
• The line pressure solenoid valve is installed to control valve.
• The line pressure solenoid valve controls the pressure regulator valve. For information about the pressure
regulator valve, refer to TM-27, "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 : Overdrive Control SwitchINFOID:0000000009463976
• The overdrive control switch is inst alled to the selector lever knob.
• If the overdrive control switch is pressed when the O/D OFF indicator lamp on the combination meter is not
lit, the status changes to overdrive OFF and the O/D OFF indicator lamp illuminates.
• If the overdrive control switch is pressed when the O/ D OFF indicator lamp on the combination meter is lit,
the overdrive OFF status is canceled and the O/D OFF indicator lamp turns off.
CVT CONTROL SYSTEM : O/D OFF Indicator LampINFOID:0000000009463977
• O/D OFF indicator lamp is positioned on the combination meter.
• The O/D OFF indicator lamp illuminates when the overdrive function is deactivated (O/D OFF).
• For checking the bulb, this lamp turns on for a cert ain period of time when the ignition switch turns ON,
andthen turns off.
CVT CONTROL SYSTEM : Sh ift Position IndicatorINFOID:0000000009463978
TCM transmits shift position signal to combination meter via CAN communication. The actual shift position is
displayed on combination meter according to the signal.
SHIFT LOCK SYSTEM
Condition (status) O/D OFF indicator lamp
Ignition switch OFF. OFF
Ignition switch ON. ON (Approx. 2 seconds)
Overdrive control switch is pressed when the selector lever is in
the D position and the O/D OFF indicator lamp is OFF (when sys-
tem is normal). ON
Overdrive control switch is pressed when the selector lever is in
the D position and the O/D OFF indicator lamp is ON. OFF
Selector lever is shifted from the D position to another position-
when the O/D OFF indicator lamp is ON. OFF
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
STRUCTURE AND OPERATIONTM-23
< SYSTEM DESCRIPTION > [CVT: RE0F10D]
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TRANSAXLE : Operation StatusINFOID:0000000009463981
× : Engaged or applied.
TRANSAXLE : Transaxle MechanismINFOID:0000000009463982
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 steel belt
(the steel plates are placed conti nuously and the belt is guided with the multilayer steel rings on both sides).
Selector lever
position Parking mech-
anism Forward
clutch Reverse brake Primary pulley Secondary
pulley Steel belt Final drive
P ×
R ×××××
N
D × ××××
DS × ××××
JSDIA2426GB
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
TM-24
< SYSTEM DESCRIPTION >[CVT: RE0F10D]
STRUCTURE AND OPERATION
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 wit h the oil pressures of primary pulley and secondary pulley.
Steel Belt
It is composed of multiple steel plates (A) and two steel rings (B)
stacked to a several number. The feature of this steel belt transmits
power with compression of the steel plate in contrast with transmis-
sion of power in pulling with a rubber belt. Friction force is required
with the pulley slope to transmit power from the steel plate. The force
is generated with the following mechanism:
Oil pressure applies to the secondary pulley to nip the plate. ⇒The
plate is pushed and extended outward. ⇒The steel ring shows with-
stands. ⇒Pulling force is generated on the steel ring. ⇒The plate of
the primary pulley is nipped between the pulley. ⇒Friction force is
generated between the steel belt and the pulley.
Therefore, responsibilities are divi ded by the steel plate that trans-
mits the power with compression and the steel ring that main tains necessary friction force. In this way, the
tension of the steel ring is distributed on the entire su rface and stress variation is limited, resulting in good
durability.
Pulley
The primary pulley (input shaft side) and the secondary pulley (output shaft side) have the shaft with slope
(fixed cone surface), movable sheave (movable cone surface that can move in the axial direction) and oil pres-
sure chamber at the back of the movable sheave.
JSDIA2428GB
JSDIA2431ZZ
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
STRUCTURE AND OPERATIONTM-27
< SYSTEM DESCRIPTION > [CVT: RE0F10D]
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TRANSAXLE : Component DescriptionINFOID:0000000009463984
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 steel 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
Steel 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-31
< SYSTEM DESCRIPTION > [CVT: RE0F10D]
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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:0000000009463988
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 ×××××
Overdrive control switch
(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) ×
O/D OFF indicator lamp
(CAN communication) ×
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM
TM-34
< SYSTEM DESCRIPTION >[CVT: RE0F10D]
SYSTEM
CVT CONTROL SYSTEM : Protection Control
INFOID:0000000009463989
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-35
< SYSTEM DESCRIPTION > [CVT: RE0F10D]
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REVERSE PROHIBIT CONTROL
LINE PRESSURE CONTROL
LINE PRESSURE CONTROL : System DescriptionINFOID:0000000009463990
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, oi l pressure, and overdrive control switch 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.)
JSDIA3781GB
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM