NISSAN LATIO 2011 Service Repair Manual

CVT-16
< SERVICE INFORMATION >[RE0F08B]
CVT FLUID
3. Disconnect the fluid cooler inlet and outlet rubber hoses from the
steel cooler tubes.
NOTE:
Replace the cooler hoses if rubber material from the hose
remains on the tube fitting.
4. Allow any CVT fluid that remains in the cooler hoses to drain into the oil pan.
5. Insert the extension adapter hose of a can of Transmission
Cooler Cleaner (Nissan P/N 999MP-AM006) into the cooler out-
let hose.
CAUTION:
• Wear safety glasses and rubber gloves when spraying the Transmission Cooler Cleaner.
• Spray Transmission Cooler Cleaner only with adequate
ventilation.
• Avoid contact with eyes and skin.
• Do not breath vapors or spray mist.
6. Hold the hose and can as high as possible and spray Transmis- sion Cooler Cleaner in a continuous stream into the cooler outlet
hose until CVT fluid flows out of the cooler inlet hose for 5 seconds.
7. Insert the tip of an air gun into the end of the cooler outlet hose.
8. Wrap a shop rag around the air gun tip and of the cooler outlet hose.
9. Blow compressed air regulated to 490 to 883 kPa (5 to 9 kg/cm
2,
71 to 128 psi) through the cooler outlet hose for 10 seconds to
force out any remaining CVT fluid.
10. Repeat steps 5 through 9 three additional times.
11. Position an oil pan under the banjo bolts that connect the CVT fluid cooler steel lines to the transaxle.
12. Remove the banjo bolts.
13. Flush each steel line from the cooler side back toward the tran- saxle by spraying Transmission Cooler Cleaner in a continuous stream for 5 seconds.
14. Blow compressed air regulated to 490 to 883 kPa (5 to 9 kg/cm
2, 71 to 128 psi) through each steel line
from the cooler side back toward the transaxle for 10 seconds to force out any remaining CVT fluid.
15. Ensure all debris is removed from the steel cooler lines.
16. Ensure all debris is removed from the banjo bolts and fittings.
17. Perform "CVT FLUID COOLER DIAGNOSIS PROCEDURE".
CVT FLUID COOLER DIAGNOSIS PROCEDURE
NOTE:
Insufficient cleaning of the cooler inlet hose exterior may lead to inaccurate debris identification.
1. Position an oil pan under the transaxle's inlet and outlet cooler hoses.
2. Clean the exterior and tip of the cooler inlet hose.
SCIA4421E
SCIA4422E
SCIA4423E
Revision: May 2010 2011 Versa

CVT FLUIDCVT-17
< SERVICE INFORMATION > [RE0F08B]
D
E
F
G H
I
J
K L
M A
B
CVT
N
O P
3. Insert the extension adapter hose of a can of Transmission Cooler Cleaner (Nissan P/N 999MP-AM006) into the cooler out-
let hose.
CAUTION:
• Wear safety glasses and rubber gloves when spraying theTransmission Cooler Cleaner.
• Spray Transmission Cooler Cleaner only with adequate
ventilation.
• Avoid contact with eyes and skin.
• Do not breath vapors or spray mist.
4. Hold the hose and can as high as possible and spray Transmis- sion Cooler Cleaner in a continuous stream into the cooler outlet
hose until CVT fluid flows out of t he cooler inlet hose for 5 seconds.
5. Tie a common white, basket-type coffee filter to the end of the cooler inlet hose.
6. Insert the tip of an air gun into the end of the cooler outlet hose.
7. Wrap a shop rag around the air gun tip and end of cooler outlet hose.
8. Blow compressed air regulated to 490 to 883 kPa (5 to 9 kg/cm
2,
71 to 128 psi) through the cooler outlet hose to force any
remaining CVT fluid into the coffee filter.
9. Remove the coffee filter from the end of the cooler inlet hose.
10. Perform "CVT FLUID COOLER INSPECTION PROCEDURE".
CVT FLUID COOLER INSPECTION PROCEDURE
1. Inspect the coffee filter for debris.
a. If small metal debris less than 1 mm (0.040 in) in size or metal powder is found in the coffee filter, this is normal. If normal
debris is found, the CVT fluid cooler/radiator can be re-used and
the procedure is ended.
SCIA4421E
SCIA4424E
SCIA4425E
SCIA2967E
Revision: May 2010 2011 Versa

CVT-18
< SERVICE INFORMATION >[RE0F08B]
CVT FLUID
b. If one or more pieces of debris are found that are over 1 mm
(0.040 in) in size and/or peeled clutch facing material is found in
the coffee filter, the fluid cooler is not serviceable. The radiator/
fluid cooler must be replac ed and the inspection procedure is
ended.
CVT FLUID COOLER FINAL INSPECTION
After performing all procedures, ensure that all remaining oil is cleaned from all components.
SCIA7031E
Revision: May 2010 2011 Versa

CVT SYSTEMCVT-19
< SERVICE INFORMATION > [RE0F08B]
D
E
F
G H
I
J
K L
M A
B
CVT
N
O P
CVT SYSTEM
Cross-Sectional View - RE0F08BINFOID:0000000005928733
1. Converter housing 2. Oil pump3. Forward clutch
4. Reverse brake 5. Planetary carrier6. Primary pulley
7. Steel belt 8. Sun gear9. Side cover
10. Internal gear 11. Secondary pulley12. Differential case
13. Final gear 14. Idler gear15. Reduction gear
16. Output gear 17. Parking gear18. Input shaft
19. Torque converter
SCIA8015E
Revision: May 2010 2011 Versa

CVT-20
< SERVICE INFORMATION >[RE0F08B]
CVT SYSTEM
Control System
INFOID:0000000005928734
AWDIA0767GB
Revision: May 2010 2011 Versa

CVT SYSTEMCVT-21
< SERVICE INFORMATION > [RE0F08B]
D
E
F
G H
I
J
K L
M A
B
CVT
N
O P
Hydraulic Control SystemINFOID:0000000005928735
TCM FunctionINFOID:0000000005928736
The function of the TCM is to:
• Receive input signals sent from various switches and sensors.
• Determine required line pressure, shifting point, and lock-up operation.
• Send required output signals to the step motor and the respective solenoids.
CONTROL SYSTEM OUTLINE
The CVT senses vehicle operating conditions through various sensors. It always controls the optimum shift
position and reduces shifting and lock-up shocks.
AWDIA0768GB
SENSORS (or SIGNAL)
⇒TCM
⇒ACTUATORS
Transmission range switch
Accelerator pedal position signal
Closed throttle position signal
Engine speed signal
CVT fluid temperature sensor
Vehicle speed signal
Overdrive control signal
Stop lamp switch signal
Primary speed sensor
Secondary speed sensor
Secondary pressure sensor Shift control
Line pressure control
Primary pressure control
Secondary pressure control
Lock-up control
Engine brake control
Vehicle speed control
Fail-safe control
Self-diagnosis
CONSULT-III co
mmunication
line
Duet-EA control
CAN system
On board diagnosis Step motor
Torque converter clutch solenoid
valve
Lock-up select solenoid valve
Line pressure solenoid valve
Secondary pressure solenoid
valve
Shift position indicator
O/D OFF indicator lamp
Starter relay
Revision: May 2010
2011 Versa

CVT-22
< SERVICE INFORMATION >[RE0F08B]
CVT SYSTEM
CONTROL SYSTEM DIAGRAM
CAN CommunicationINFOID:0000000005928737
SYSTEM DESCRIPTION
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication s
peed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CA N communication, control units are connected with 2
communication lines (CAN-H line, CAN-L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only. For details, refer to LAN-7,
"System Description".
Input/Output Signal of TCMINFOID:0000000005928738
AWDIA0769GB
Control itemFluid
pressure control Select con-
trol Shift control Lock-up
control CAN com-
munication control Fail-safe
function (*3)
Input T
ra n sm is sio n r ang e s wit c h XXXXXX
Accelerator pedal position signal
(*1)XXXXXX
Closed throttle position signal
(*1)X XXX
Engine speed signal
(*1)XX XXX
CVT fluid temperature sensor XX XX X
Stop lamp switch signal
(*1)X XXX
Overdrive control signal
(*1)XX
Primary speed sensor X XXXX
Secondary speed sensor XXXXXX
Secondary pressure sensor XX X
T C M pow er s upp ly v olt a ge s ig n al XXXXXX
Revision: May 2010 2011 Versa

CVT SYSTEMCVT-23
< SERVICE INFORMATION > [RE0F08B]
D
E
F
G H
I
J
K L
M A
B
CVT
N
O P
*1: Input by CAN communications.
*2: Output by CAN communications.
*3: If these input and output signals are different, the TCM triggers the fail-safe function.
Line Pressure and Secondary Pressure ControlINFOID:0000000005928739
• 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 valve and secondary pressure solenoid valve.
• This line pressure solenoid controls the pressure regulat or valve as the signal pressure and adjusts the pres-
sure of the operating oil discharged from the oil pump to the line pressure most appropriate to the driving
state. Secondary pressure is cont rolled by decreasing line pressure.
NORMAL CONTROL
Optimize the line pressure and secondary pressure, dependi ng on driving conditions, on the basis of the throt-
tle position, the engine speed, the primary pulley (input ) revolution speed, the secondary pulley (output) revo-
lution speed, the brake signal, the transmission range switch signal, the lock-up signal, the voltage, the target
gear ratio, the fluid temperat ure, and the fluid pressure.
FEEDBACK CONTROL
When controlling the normal fluid pressure or the sele cted fluid pressure, the secondary pressure can be set
more accurately by using the fluid pressure sensor to detect the secondary pressure and controlling the feed-
back.
Shift ControlINFOID:0000000005928740
In order to select the gear ratio which can obtain the dr iving force in accordance with driver's intention and the
vehicle condition, TCM monitors the driving conditions, such as the vehicle speed and the throttle position and
selects the optimum gear ratio, and determines the gear change steps to the gear ratio. Then send the com-
Out-
putSte p mo tor
XX
TCC solenoid valve XXX
Lock-up select solenoid valve XXX
Line pressure solenoid valve XXX X
Secondary pressure solenoid valve XX X
O/D OFF indicator signal
(*2)XX
Control item
Fluid
pressure
control Select con-
trol Shift control
Lock-up
control CAN com-
munication
control Fail-safe
function
(*3)
SCIA1846E
Revision: May 2010 2011 Versa

CVT-24
< SERVICE INFORMATION >[RE0F08B]
CVT SYSTEM
mand to the step motor, and control the flow-in/flow-out of line pressure from the primary pulley to determine
the position of the moving-pulley and control the gear ratio.
NOTE:
The gear ratio is set for every position separately.
“D” POSITION
Shifting over all the ranges of gear ratios from the lowest to the high-
est.
OVERDRIVE-OFF MODE
Use this position for the improved engine braking.
“L” POSITION
By limiting the gear range to the lowest position, the strong driving
force and the engine brake can be secured.
DOWNHILL ENGINE BRAKE CONTROL
(AUTO ENGINE BRAKE CONTROL)
When downhill is detected with the accelerator pedal released, the engine brake will be strengthened up by
downshifting so as not to accelerate the vehicle more than necessary.
ACCELERATION CONTROL
According to vehicle speed and a change of accelerator pedal angle, driver's request for acceleration and driv-
ing scene are judged. This function assists improvem ent in acceleration feeling by making the engine speed
proportionate to the vehicle speed. And a shift map which can gain a larger driving force is available for com-
patibility of mileage with driveability.
AWDIA0770GB
SCIA1953E
SCIA1955E
Revision: May 2010 2011 Versa

CVT SYSTEMCVT-25
< SERVICE INFORMATION > [RE0F08B]
D
E
F
G H
I
J
K L
M A
B
CVT
N
O P
Lock-up and Select ControlINFOID:0000000005928741
• The torque converter clutch piston in the torque conv erter 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. The torque converter clutch control valve engages or
releases the torque converter clutch piston.
• When shifting between “N” (“P”) ⇒“D” (“R”), torque converter clutch solenoid controls engagement power of
forward clutch and reverse brake.
• The lock-up applied gear range was expanded by locking up the torque converter at a lower vehicle speed than conventional CVT
models.
TORQUE CONVERTER CLUTCH AND SELECT CONTROL VALVE CONTROL
Lock-up and Select Control System Diagram
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.
Select Control
When shifting between “N” (“P”) ⇒“D” (“R”), optimize the operating pressure on the basis of the throttle posi-
tion, the engine speed, and the secondary pulley (out put) revolution speed to lessen the shift shock.
Control ValveINFOID:0000000005928742
FUNCTION OF CONTROL VALVE
SCIA1958E
AWDIA0778GB
Revision: May 2010 2011 Versa