NISSAN TEANA 2003 Service Manual

CVT SYSTEM
CVT-15
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CVT

CVT SYSTEMPFP:31036
Cross-Sectional View - RE0F09ABCS001FZ
1. Converter housing 2. Oil pump 3. Forward clutch
4. Reverse brake 5. Planetary carrier 6. Primary pulley
7. Steel belt 8. Sun gear 9. Side cover
10. Internal gear 11. Secondary pulley 12. Final gear
13. Differential case 14. Idler gear 15. Reduction gear
16. Taper roller bearing 17. Output gear 18. Parking gear
19. Input shaft 20. Torque converter
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CVT-16
CVT SYSTEM

Control SystemBCS001G0
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CVT SYSTEM
CVT-17
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Hydraulic Control SystemBCS001G1
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CVT-18
CVT SYSTEM

TCM FunctionBCS001G2
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.
CONTROL SYSTEM DIAGRAM
SENSORS (or SIGNAL)

TCM

ACTUATORS
PNP switch
Accelerator pedal position signal
Closed throttle position signal
Engine speed signal
CVT fluid temperature sensor
Vehicle speed signal
Manual mode signal
Stop lamp switch signal
Primary speed sensor
Secondary speed sensor
Primary pressure sensor
Secondary pressure sensorShift 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-II communication line
Duet-EA control
CAN systemSte p mo tor
Torque converter clutch solenoid
valve
Lock-up select solenoid valve
Line pressure solenoid valve
Secondary pressure solenoid
valve
Manual mode indicator
Shift position indicator
CVT indicator lamp
Starter relay
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CVT SYSTEM
CVT-19
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CVT

CAN CommunicationBCS001G3
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-49,
"CAN System Specification Chart" .
Input/Output Signal of TCMBCS001G4
*1: Input by CAN communications.
*2: If these input and output signals are different, the TCM triggers the fail-safe function. Control item Fluid
pressure
control Select
control Shift con-
trol Lock-up
control CAN com-
munication
control Fail-safe
function
(*2)
Input PNP switch XXXXXX
Accelerator pedal position signal
(*1)XXXXXX
Closed throttle position signal
(*1)XXXX
Engine speed signal
(*1)XX XXX
CVT fluid temperature sensor X X X X X
Manual mode signal
(*1)XXXXX
Stop lamp switch signal
(*1)XXXX
Primary speed sensor X X X X X
Secondary speed sensor X X X X X X
Primary pressure sensor X X
Secondary pressure sensor X X X
TCM power supply voltage signal X X X X X X
Out-
put Step 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

CVT-20
CVT SYSTEM

Line Pressure and Secondary Pressure ControlBCS001G5

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 ControlBCS001G6
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.
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CVT SYSTEM
CVT-21
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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.
“M” POSITION
When the selector lever is put in the manual shift gate side, the fixed
changing gear line is set. By moving the selector lever to + side or -
side, the manual mode switch is changed over, and shift change like
M/T becomes possible following the changing gear set line step by
step.
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 improvement 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 drivability.
Lock-up and Select ControlBCS001G7

The torque converter clutch piston in the torque converter 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.
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CVT-22
CVT SYSTEM

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 (output) revolution speed to lessen the shift shock.
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CVT SYSTEM
CVT-23
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Control ValveBCS001G8
FUNCTION OF CONTROL VALVE
Name Function
Torque converter regulator valve Optimizes the supply pressure for the torque converter depending on driving conditions
Pressure regulator valve Optimizes the discharge pressure from the oil pump depending on driving conditions
TCC control valve

Activates or deactivate the lock-up

Lock-up smoothly by opening lock-up operation excessively
TCC solenoid valve Controls the TCC control valve or select control valve
Shift control valveControls flow-in/out of line pressure from the primary pulley depending on the stroke dif-
ference between the stepping motor and the primary pulley
Secondary valve Controls the line pressure from the secondary pulley depending on operating conditions
Clutch regulator valve Adjusts the clutch operating pressure depending on operating conditions
Secondary pressure solenoid valve Controls the secondary valve
Line pressure solenoid valve Controls the line pressure control valve
Step motor Controls the pulley ratio
Manual valveTransmits the clutch operating pressure to each circuit in accordance with the selected
position
Select control valve Engages forward clutch, reverse brake smoothly depending on select operation
Select switch valveSwitches torque converter clutch solenoid valve control pressure use to torque con-
verter clutch control valve or select control valve
Lock-up select solenoid valve Controls the select switch valve

CVT-24
TROUBLE DIAGNOSIS

TROUBLE DIAGNOSISPFP:00004
DTC Inspection Priority ChartBCS001GE
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-53
.
Fail-safeBCS001GF
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-SAFE FUNCTION
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 manual mode position and second position is
inhibited, and the transaxle 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 manual
mode position and second position 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”.
Manual Mode Switch
If an unexpected signal is sent from the manual mode 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 5,000
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.
Priority Detected items (DTC)
1 U1000 CAN communication line
2 Except above