2011 NISSAN LATIO transmission

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 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

ON BOARD DIAGNOSTIC (OBD) SYSTEMCVT-27
< SERVICE INFORMATION > [RE0F08B]
D
E
F
G H
I
J
K L
M A
B
CVT
N
O P
ON BOARD DIAGNOSTIC (OBD) SYSTEM
IntroductionINFOID:0000000005928743
The CVT system has two self-diagnostic systems.
The first is the emission-related on board diagnostic syst em (OBD-II) performed by the TCM in combination
with the ECM. The malfunction is indicated by the MI L (malfunction indicator lamp) and is stored as a DTC in
the ECM memory, and the TCM memory.
The second is the TCM original self-diagnosis perform ed by the TCM. The malfunction is stored in the TCM
memory. The detected items are overlapped with OBD-II self-diagnostic items. For detail, refer to CVT-48,
"CONSULT-III Function (TRANSMISSION)".
OBD-II Function for CVT SystemINFOID:0000000005928744
The ECM provides emission-related on board diagnostic (OBD-II) functions for the CVT system. One function
is to receive a signal from the TCM used with OBD-relat ed parts of the CVT system. The signal is sent to the
ECM when a malfunction occurs in the corresponding OBD-re lated part. The other function is to indicate a
diagnostic result by means of the MIL (malfunction indica tor lamp) on the instrument panel. Sensors, switches
and solenoid valves are used as sensing elements.
The MIL automatically illuminates in One or Two Trip Detection Logic when a malfunction is sensed in relation
to CVT system parts.
One or Two Trip Detection Logic of OBD-IIINFOID:0000000005928745
ONE TRIP DETECTION LOGIC
If a malfunction is sensed during the first test drive, the MIL will illuminate and the malfunction will be stored in
the ECM memory as a DTC. The TCM is not provided with such a memory function.
TWO TRIP DETECTION LOGIC
When a malfunction is sensed during the first test drive, it is stored in the ECM memory as a 1st trip DTC
(diagnostic trouble code) or 1st trip freeze frame data. At this point, the MIL will not illuminate. — 1st trip
If the same malfunction as that experienced during the fi rst test drive is sensed during the second test drive,
the MIL will illuminate. — 2nd trip
The “trip” in the “One or Two Trip Detection Logic” m eans a driving mode in which self-diagnosis is performed
during vehicle operation.
OBD-II Diagnostic Trouble Code (DTC)INFOID:0000000005928746
HOW TO READ DTC AND 1ST TRIP DTC
DTC and 1st trip DTC can be read by the following methods.
( with CONSULT-III or GST) CONSULT-III or GST (Generic Scan Tool) Examples: P0705, P0720 etc.
These DTC are prescribed by SAE J2012.
(CONSULT-III also displays the malfunctioning component or system.)
• 1st trip DTC No. is the same as DTC No.
• Output of the diagnostic trouble code indicates that the indicated circuit has a malfunction. How-
ever, in case of the Mode II and GST, they do not indicate whether the malfunction is still occurring or
occurred in the past and returned to normal.
CONSULT-III can identify them as shown below, therefore, CONS ULT-III (if available) is recom-
mended.
DTC or 1st trip DTC of a malfunction is displayed in SELF-DIAGNOSTIC RESULTS mode for “ENGINE” with
CONSULT-III. Time data indicates how many times the vehicle was driven after the last detection of a DTC.
If the DTC is being detected curr ently, the time data will be “0”.
If a 1st trip DTC is stored in the ECM, the time data will be “1t”.
Freeze Frame Data and 1st Trip Freeze Frame Data
Revision: May 2010 2011 Versa

CVT-28
< SERVICE INFORMATION >[RE0F08B]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
The ECM has a memory function, which stores the driv
ing condition such as fuel system status, calculated
load value, engine coolant temperatur e, short term fuel trim, long term fuel trim, engine speed and vehicle
speed at the moment the ECM detects a malfunction.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data,
and the data, stored together with the DTC data, are called freeze frame data and displayed on CONSULT-III
or GST. The 1st trip freeze frame data can only be disp layed on the CONSULT-III screen, not on the GST. For
details, refer to EC-612, "
CONSULT-III Function (ENGINE)".
Only one set of freeze frame data (either 1st trip freez e frame data or freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM memory along with the 1st trip DTC. There is no priority
for 1st trip freeze frame data, and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MIL on) is stored in the ECM memory, 1st trip freeze frame data is no
longer stored. Remember, only one set of freeze frame data can be stored in the ECM. The ECM has the fol-
lowing priorities to update the data.
Both 1st trip freeze frame data and freeze frame dat a (along with the DTC) are cleared when the ECM mem-
ory is erased.
HOW TO ERASE DTC
The diagnostic trouble code can be erased by CONSULT- III, GST or ECM DIAGNOSTIC TEST MODE as
described following.
• If the battery cable is disconnected, the diagnosti c trouble code will be lost within 24 hours.
• When you erase the DTC, using CONSULT-III or GS T is easier and quicker than switching the mode
selector on the ECM.
The following emission-related diagnostic information is cleared from the ECM memory when erasing DTC
related to OBD-II. For details, refer to EC-542, "
Emission-related Diagnostic Information".
• Diagnostic trouble codes (DTC)
• 1st trip diagnostic trou ble codes (1st trip DTC)
• Freeze frame data
• 1st trip freeze frame data
• System readiness test (SRT) codes
• Test values
HOW TO ERASE DTC (WITH CONSULT-III)
•If a DTC is displayed for both ECM and TCM, it is necessary to be erased for both ECM and TCM.
1. If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10 seconds and then turn it ON (engine stopped) again.
2. Turn CONSULT-III ON and touch “TRANSMISSION”.
3. Touch “SELF-DIAG RESULTS”.
4. Touch “ERASE”. (The DTC in the TCM will be erased.) Then touch “BACK” twice.
5. Touch “ENGINE”.
6. Touch “SELF-DIAG RESULTS”.
7. Touch “ERASE”. (The DTC in the ECM will be erased.)
HOW TO ERASE DTC (WITH GST)
1. If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10 seconds and then turn it ON (engine stopped) again.
2. Select Mode 4 with GST (Generic Scan Tool). For details, refer to EC-618, "
Generic Scan Tool (GST)
Function".
Malfunction Indicator Lamp (MIL)INFOID:0000000005928747
DESCRIPTION
PriorityItems
1 Freeze frame data Misfire — DTC: P0300 - P0306
Fuel Injection System Function — DTC: P0171, P0172, P0174, P0175
2 Except the above items (Includes CVT related items)
3 1st trip freeze frame data
Revision: May 2010 2011 Versa

CVT-30
< SERVICE INFORMATION >[RE0F08B]
TROUBLE DIAGNOSIS
TROUBLE DIAGNOSIS
DTC Inspection Priority ChartINFOID:0000000005928748
If some DTCs are displayed at the same time, perform inspections one by one based on the following priority
chart.
NOTE:
If DTC “U1000” is displayed with other DTCs, first perform the trouble diagnosis for DTC “U1000”.
Refer to
CVT-56
.
Fail-SafeINFOID:0000000005928749
The TCM has an electrical fail-safe mode. This mode make s it possible to operate even if there is an error in a
main electronic control input/output signal circuit.
FAIL-SAFE FUNCTION
If any malfunction occurs in a sensor or solenoid, this function controls the CVT to make driving possible.
Secondary Speed Sensor
The shift pattern is changed in accordance with thrott le position when an unexpected signal is sent from the
secondary speed sensor to the TCM. T he overdrive-off mode is inhibited, and the transaxle is put in “D”.
Primary Speed Sensor
The shift pattern is changed in accordance with thro ttle position and secondary speed (vehicle speed) when
an unexpected signal is sent from the primary speed sensor to the TCM. The overdrive-off mode is inhibited,
and the transaxle is put in “D”.
Transmission Range Switch
If an unexpected signal is sent from the transmission range switch to the TCM, the transaxle is put in “D”.
CVT Fluid Temperature Sensor
If an unexpected signal is sent from the CVT fluid temperature sensor to the TCM, the gear ratio in use before
receiving the unexpected signal is maintained or t he gear ratio is controlled to keep engine speed under 3500
rpm.
Secondary Pressure Sensor
• If an unexpected signal is sent from the secondary pressure sensor to the TCM, the secondary pressure
feedback control is stopped and the offset value obtai ned before the non-standard condition occurs is used
to control line pressure.
• If secondary pressure sensor error signal is input to TCM, secondary pressure feedback control stops, but line pressure is controlled normally.
Line Pressure Solenoid
If an unexpected signal is sent from the solenoid to the TCM, the line pressure solenoid is turned OFF to
achieve the maximum fluid pressure.
Secondary Pressure Solenoid
If an unexpected signal is sent from the solenoid to t he TCM, the secondary pressure solenoid is turned OFF
to achieve the maximum fluid pressure.
Torque Converter Clutch Solenoid
If an unexpected signal is sent from the solenoid to t he TCM, the torque converter clutch solenoid is turned
OFF to cancel the lock-up.
Step Motor
If an unexpected signal is sent from the step motor to the TCM, the step motor coil phases “A” through “D” are
all turned OFF to hold the gear ratio used right before the non-standard condition occurred.
CVT Lock-up Select Solenoid
If an unexpected signal is sent from the solenoid to the TCM, the CVT lock-up select solenoid is turned OFF to
cancel the lock-up.
Priority Detected items (DTC)
1 U1000
2 Except above
Revision: May 2010 2011 Versa

TROUBLE DIAGNOSISCVT-31
< SERVICE INFORMATION > [RE0F08B]
D
E
F
G H
I
J
K L
M A
B
CVT
N
O P
TCM Power Supply (Memory Back-up)
Transaxle assembly is protected by limiting the engine torque when the memory back-up power supply (for
controlling) from the battery is not supplied to TCM.
Normal statues is restored when turning the ignition switch
OFF to ON after the normal power supply.
How to Perform Trouble Diagnosis for Quick and Accurate RepairINFOID:0000000005928750
INTRODUCTION
The TCM receives a signal from the vehicle speed sensor, transmission range switch and provides shift con-
trol or lock-up control via CVT solenoid valves.
The TCM also communicates with the ECM by means of a signal
sent from sensing elements used wit h the OBD-related parts of the
CVT system for malfunction-diagnos tic purposes. The TCM is capa-
ble of diagnosing malfunctioning parts while the ECM can store mal-
functions in its memory.
Input and output signals must always be correct and stable in the
operation of the CVT system. The CVT system must be in good
operating condition and be free of valve seizure, solenoid valve mal-
function, etc.
It is much more difficult to diagnose an error that occurs intermit-
tently rather than continuously. Most intermittent errors are caused
by poor electric connections or impr oper wiring. In this case, careful
checking of suspected circuits may help prevent the replacement of
good parts.
A visual check only may not find t he cause of the errors. A road test
with CONSULT-III (or GST) or a circuit tester connected should be
performed. Follow the "WORK FLOW" .
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such errors, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “DIAGNOSTIC WORKSHEET” as
shown on the example (Refer to "Diagnostic Worksheet Chart" )
should be used.
Start your diagnosis by looking for “conventional” errors first. This will
help troubleshoot driveability errors on an electronically controlled
engine vehicle.
Also check related Service bulletins.
WORK FLOW
A good understanding of the malfunction conditions can make troubleshooting faster and more accurate.
In general, each customer feels differently about a malf unction. It is important to fully understand the symp-
toms or conditions for a customer complaint.
Make good use of the two sheets provided, "Information From Customer" and "Diagnostic Worksheet Chart" ,
to perform the best troubleshooting possible.
Work Flow Chart
SAT631IB
SAT632I
SEF234G
Revision: May 2010 2011 Versa