2007 NISSAN LATIO Fluid

CVT SYSTEM
CVT-25
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CVT
Revision: June 20062007 Versa
CAN CommunicationUCS005XU
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 speed 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 CAN 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-47,
"CAN System Specification Chart" .
Input/Output Signal of TCMUCS005XV
*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.Control itemFluid
pressure
controlSelect con-
trolShift con-
trolLock-up
controlCAN com-
munication
controlFail-safe
function
(*3)
InputPNP switch XXXXXX
Accelerator pedal position signal
(*1)XXXXXX
Closed throttle position signal
(*1)X XXX
Engine speed signal
(*1)XX XXX
CVT fluid temperature sensor X X X X X
Stop lamp switch signal
(*1)X XXX
Overdrive control signal
(*1)XX
Primary speed sensor X XXXX
Secondary speed sensor XXXXXX
Primary pressure sensor X X
Secondary pressure sensor X X X
TCM power supply voltage signal XXXXXX
Out-
putStep motor X X
TCC solenoid valve X X X
Lock-up select solenoid valve X X X
Line pressure solenoid valve X X X X
Secondary pressure solenoid valve X X X
O/D OFF indicator signal
(*2)XX

CVT-26
CVT SYSTEM
Revision: June 20062007 Versa
Line Pressure and Secondary Pressure ControlUCS005XW

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 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. Secondary pressure is controlled by decreasing line pressure.
NORMAL CONTROL
Optimize the line pressure and secondary pressure, depending 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 PNP switch signal, the lock-up signal, the voltage, the target gear ratio, the
fluid temperature, and the fluid pressure.
FEEDBACK CONTROL
When controlling the normal fluid pressure or the selected 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 ControlUCS005XX
In order to select the gear ratio which can obtain the driving 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-
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.
SCIA1846E
SCIA7958E

CVT-34
TROUBLE DIAGNOSIS
Revision: June 20062007 Versa
TROUBLE DIAGNOSISPFP:00004
DTC Inspection Priority ChartUCS005Y5
If some DTCs are displayed at the same time, perform inspections one by one based on the following priority
chart.
NOTE:
If DTC “U1000 CAN COMM CIRCUIT” is displayed with other DTCs, first perform the trouble diagnosis
for “DTC U1000 CAN COMMUNICATION LINE”. Refer to CVT-68
.
Fail-safeUCS005Y6
The TCM has an electrical fail-safe mode. This mode makes it possible to operate even if there is an error in a
main electronic control input/output signal circuit.
FAIL -S AFE F UN CTI ON
If any malfunction occurs in a sensor or solenoid, this function controls the CVT to make driving possible.
Output Speed Sensor (Secondary Speed Sensor)
The shift pattern is changed in accordance with throttle position when an unexpected signal is sent from the
output speed sensor (secondary speed sensor) to the TCM. The overdrive-off mode is inhibited, and the tran-
saxle is put in “D”.
Input Speed Sensor (Primary Speed Sensor)
The shift pattern is changed in accordance with throttle position and secondary speed (vehicle speed) when
an unexpected signal is sent from the input speed sensor (primary speed sensor) to the TCM. The sport mode
is inhibited, and the transaxle is put in “D”.
PNP Switch
If an unexpected signal is sent from the PNP 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 the gear ratio is controlled to keep engine speed under 3500
rpm.
Transmission Fluid Pressure Sensor A (Secondary Pressure Sensor)

If an unexpected signal is sent from the transmission fluid pressure sensor A (secondary pressure sensor)
to the TCM, the secondary pressure feedback control is stopped and the offset value obtained before the
non-standard condition occurs is used to control line pressure.

If transmission fluid pressure sensor A (secondary pressure sensor) error signal is input to TCM, second-
ary pressure feedback control stops, but line pressure is controlled normally.
Pressure Control Solenoid A (Line Pressure Solenoid)
If an unexpected signal is sent from the solenoid to the TCM, the pressure control solenoid A (line pressure
solenoid) is turned OFF to achieve the maximum fluid pressure.
Pressure Control Solenoid B (Secondary Pressure Solenoid)
If an unexpected signal is sent from the solenoid to the TCM, the pressure control solenoid B (secondary pres-
sure solenoid) is turned OFF to achieve the maximum fluid pressure.
Torque Converter Clutch Solenoid
If an unexpected signal is sent from the solenoid to the 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.
Priority Detected items (DTC)
1 U1000 CAN communication line
2 Except above

TROUBLE DIAGNOSIS
CVT-37
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CVT
Revision: June 20062007 Versa
DIAGNOSTIC WORKSHEET
Information From Customer
KEY POINTS

WHAT..... Vehicle & CVT model

WHEN..... Date, Frequencies

WHERE..... Road conditions

HOW..... Operating conditions, Symptoms
Diagnostic Worksheet Chart
Customer name MR/MS Model & Year VIN
Trans. Model Engine Mileage
malfunction Date Manuf. Date In Service Date
Frequency❏ Continuous❏ Intermittent ( times a day)
Symptoms❏ Vehicle does not move. (❏ Any position❏ Particular position)
❏ No shift
❏ Lock-up malfunction
❏ Shift shock or slip (❏ N → D❏ N → R❏ Lock-up❏ Any drive position)
❏ Noise or vibration
❏ No pattern select
❏ Others
()
Malfunction indicator lamp (MIL)❏ Continuously lit❏ Not lit
1❏ Read the item on cautions concerning fail-safe and understand the customer's complaint.CVT-34
2❏ CVT fluid inspection
CVT-43❏ Leak (Repair leak location.)
❏ Sta te
❏ Amount
3❏ Stall test and line pressure test
CVT-43
,
CVT-45
❏ Stall test
❏ Torque converter one-way clutch
❏ Reverse brake
❏ Forward clutch
❏ Steel belt❏ Engine
❏ Line pressure low
❏ Primary pulley
❏ Secondary pulley
❏ Line pressure inspection - Suspected part:

CVT-38
TROUBLE DIAGNOSIS
Revision: June 20062007 Versa
4❏ Perform road test.CVT-46
4-1.Check before engine is started CVT-49
❏ CVT-180, "O/D OFF Indicator Lamp Does Not Come On"
❏ Perform self-diagnosis. Enter checks for detected items. CVT-60
❏ CVT-68, "DTC U1000 CAN COMMUNICATION LINE"
❏ CVT-72, "DTC P0615 START SIGNAL CIRCUIT"
❏ CVT-76, "DTC P0703 STOP LAMP SWITCH CIRCUIT"
❏ CVT-78, "DTC P0705 PARK/NEUTRAL POSITION SWITCH"
❏ CVT-85, "DTC P0710 CVT FLUID TEMPERATURE SENSOR CIRCUIT"
❏ CVT-90, "DTC P0715 INPUT SPEED SENSOR CIRCUIT (PRI SPEED SENSOR)"
❏ CVT-95, "DTC P0720 VEHICLE SPEED SENSOR CVT (SECONDARY SPEED
SENSOR)"
❏ CVT-101, "DTC P0725 ENGINE SPEED SIGNAL"
❏ CVT-103, "DTC P0730 BELT DAMAGE"
❏ CVT-105, "DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE"
❏ CVT-110, "DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)"
❏ CVT-113, "DTC P0745 LINE PRESSURE SOLENOID VALVE"
❏ CVT-118, "DTC P0746 PRESSURE CONTROL SOLENOID A PERFORMANCE
(LINE PRESSURE SOLENOID VALVE)"
❏ CVT-121, "DTC P0776 PRESSURE CONTROL SOLENOID B PERFORMANCE
(SEC PRESSURE SOLENOID VALVE)"
❏ CVT-124, "DTC P0778 PRESSURE CONTROL SOLENOID B ELECTRICAL (SEC
PRESSURE SOLENOID VALVE)"
❏ CVT-129, "DTC P0840 TRANSMISSION FLUID PRESSURE SENSOR A CIRCUIT
(SEC PRESSURE SENSOR)"
❏ CVT-134, "DTC P0841 PRESSURE SENSOR FUNCTION"
❏ CVT-137, "DTC P0845 TRANSMISSION FLUID PRESSURE SENSOR B CIRCUIT
(PRI PRESSURE SENSOR)"
❏ CVT-142, "DTC P0868 SECONDARY PRESSURE DOWN"
❏ CVT-145, "DTC P1701 TRANSMISSION CONTROL MODULE (POWER SUPPLY)"
❏ CVT-150, "DTC P1705 THROTTLE POSITION SENSOR"
❏ CVT-152, "DTC P1722 ESTM VEHICLE SPEED SIGNAL"
❏ CVT-154, "DTC P1723 CVT SPEED SENSOR FUNCTION"
❏ CVT-156, "DTC P1726 ELECTRIC THROTTLE CONTROL SYSTEM"
❏ CVT-158, "DTC P1740 LOCK-UP SELECT SOLENOID VALVE CIRCUIT"
❏ CVT-164, "DTC P1777 STEP MOTOR - CIRCUIT"
❏ CVT-168, "DTC P1778 STEP MOTOR - FUNCTION"
4-2.Check at idleCVT-49
❏ CVT-181, "Engine Cannot Be Started in “P” and “N” Position"
❏ CVT-182, "In “P” Position, Vehicle Moves Forward or Backward When Pushed"
❏ CVT-182, "In “N” Position, Vehicle Moves"
❏ CVT-183, "Large Shock “N” → “R” Position"
❏ CVT-184, "Vehicle Does Not Creep Backward in “R” Position"
❏ CVT-185, "Vehicle Does Not Creep Forward in “D” or “L” Position"

TROUBLE DIAGNOSIS
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CVT
Revision: June 20062007 Versa
44-3.Cruise testCVT-50
❏ CVT-186, "Vehicle Speed Does Not Change in “L” Position"
❏ CVT-187, "Vehicle Speed Does Not Change in overdrive-off mode"
❏ CVT-188, "Vehicle Speed Does Not Change in “D” Position"
❏ CVT-189, "Vehicle Does Not Decelerate by Engine Brake"
❏ perform self-diagnosis. Enter checks for detected items. CVT-60
❏ CVT-68, "DTC U1000 CAN COMMUNICATION LINE"
❏ CVT-72, "DTC P0615 START SIGNAL CIRCUIT"
❏ CVT-76, "DTC P0703 STOP LAMP SWITCH CIRCUIT"
❏ CVT-78, "DTC P0705 PARK/NEUTRAL POSITION SWITCH"
❏ CVT-85, "DTC P0710 CVT FLUID TEMPERATURE SENSOR CIRCUIT"
❏ CVT-90, "DTC P0715 INPUT SPEED SENSOR CIRCUIT (PRI SPEED SENSOR)"
❏ CVT-95, "DTC P0720 VEHICLE SPEED SENSOR CVT (SECONDARY SPEED
SENSOR)"
❏ CVT-101, "DTC P0725 ENGINE SPEED SIGNAL"
❏ CVT-103, "DTC P0730 BELT DAMAGE"
❏ CVT-105, "DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE"
❏ CVT-110, "DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)"
❏ CVT-113, "DTC P0745 LINE PRESSURE SOLENOID VALVE"
❏ CVT-118, "DTC P0746 PRESSURE CONTROL SOLENOID A PERFORMANCE
(LINE PRESSURE SOLENOID VALVE)"
❏ CVT-121, "DTC P0776 PRESSURE CONTROL SOLENOID B PERFORMANCE
(SEC PRESSURE SOLENOID VALVE)"
❏ CVT-124, "DTC P0778 PRESSURE CONTROL SOLENOID B ELECTRICAL (SEC
PRESSURE SOLENOID VALVE)"
❏ CVT-129, "DTC P0840 TRANSMISSION FLUID PRESSURE SENSOR A CIRCUIT
(SEC PRESSURE SENSOR)"
❏ CVT-134, "DTC P0841 PRESSURE SENSOR FUNCTION"
❏ CVT-137, "DTC P0845 TRANSMISSION FLUID PRESSURE SENSOR B CIRCUIT
(PRI PRESSURE SENSOR)"
❏ CVT-142, "DTC P0868 SECONDARY PRESSURE DOWN"
❏ CVT-145, "DTC P1701 TRANSMISSION CONTROL MODULE (POWER SUPPLY)"
❏ CVT-150, "DTC P1705 THROTTLE POSITION SENSOR"
❏ CVT-152, "DTC P1722 ESTM VEHICLE SPEED SIGNAL"
❏ CVT-154, "DTC P1723 CVT SPEED SENSOR FUNCTION"
❏ CVT-156, "DTC P1726 ELECTRIC THROTTLE CONTROL SYSTEM"
❏ CVT-158, "DTC P1740 LOCK-UP SELECT SOLENOID VALVE CIRCUIT"
❏ CVT-164, "DTC P1777 STEP MOTOR - CIRCUIT"
❏ CVT-168, "DTC P1778 STEP MOTOR - FUNCTION"
5❏ Inspect each system for items found to be NG in the self-diagnosis and repair or replace the malfunctioning parts.
6❏ Perform all road tests and enter the checks again for the required items.CVT-46
7❏ For any remaining NG items, perform the “diagnosis procedure” and repair or replace the malfunctioning parts.
8❏ Erase the results of the self-diagnosis from the TCM.CVT-32
,
CVT-32

TROUBLE DIAGNOSIS
CVT-43
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CVT
Revision: June 20062007 Versa
Inspections before Trouble DiagnosisUCS005YB
CVT FLUID CHECK
Fluid Leakage and Fluid Level Check

Inspect for fluid leakage and check the fluid level. Refer to CVT-16, "Checking CVT Fluid" .
Fluid Condition Check
Inspect the fluid condition.
STALL TEST
Stall Test Procedure
1. Inspect the amount of engine oil. Replenish the engine oil if necessary.
2. Drive for about 10 minutes to warm up the vehicle so that the
CVT fluid temperature is 50 to 80°C (122 to 176°F). Inspect the
amount of CVT fluid. Replenish if necessary.
3. Securely engage the parking brake so that the tires do not turn.
4. Install a tachometer where it can be seen by driver during test.

It is good practice to mark the point of specified engine
rpm on indicator.
5. Start engine, apply foot brake, and place selector lever in “D”
position.
Fluid status Conceivable cause Required operation
Varnished (viscous
varnish state)Clutch, brake
scorchedReplace the CVT fluid and check
the CVT main unit and the vehicle
for malfunctions (wire harnesses,
cooler pipes, etc.)
Milky white or
cloudyWater in the fluidReplace the CVT fluid and check for
places where water is getting in.
Large amount of
metal powder mixed
inUnusual wear of
sliding parts within
CVTReplace the CVT fluid and check for
improper operation of the CVT.
SAT6 3 8A
SAT6 4 7B
SAT5 1 3G
SAT7 7 5B

CVT-44
TROUBLE DIAGNOSIS
Revision: June 20062007 Versa
6. While holding down the foot brake, gradually press down the
accelerator pedal.
7. Quickly read off the stall speed, and then quickly remove your
foot from the accelerator pedal.
CAUTION:
Do not hold down the accelerator pedal for more than 5 sec-
onds during this test.
8. Move the selector lever to the “N” position.
9. Cool down the CVT fluid.
CAUTION:
Run the engine at idle for at least 1 minute.
10. Repeat steps 6 through 9 with selector lever in “R” position.
Judgement Stall Test
O: Stall speed within standard value position.
H: Stall speed is higher than standard value.
L: Stall speed is lower than standard value.
Stall speed: 2,600 - 3,150 rpm
SAT5 1 4G
SAT7 7 1B
Selector lever position
Expected problem location
“D” “R”
Stall rotation HO

Forward clutch
OH

Reverse brake
LL

Engine and torque converter one-way clutch
HH

Line pressure low

Primary pulley

Secondary pulley

Steel belt