Nissan Versa Sedan. Instruction — part 795

TM-86

< SYSTEM DESCRIPTION >

[4AT: RE4F03C]

SYSTEM

When the A/T fluid temperature drops below the prescribed tempera-

ture, in order to speed up the action of each friction element, the line

pressure is set higher than the normal line pressure characteristic.

SHIFT CHANGE CONTROL
SHIFT CHANGE CONTROL : System Diagram

INFOID:0000000009267849

SHIFT CHANGE CONTROL : System Description

INFOID:0000000009267850

The clutch pressure control solenoid is controlled by the signals from the switches and sensors. Thus, the

clutch pressure is adjusted to be appropriate to the engine load state and vehicle driving state. It becomes

possible to finely control the clutch hydraulic pressure with high precision and a smoother shift change charac-

teristic is attained.

The clutch is controlled with the optimum timing and oil pressure by the engine speed, engine torque informa-

tion, etc.

PCIA0011E

JSDIA2059GB

JSDIA1984ZZ

SYSTEM

TM-87

< SYSTEM DESCRIPTION >

[4AT: RE4F03C]

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Shift Change System Diagram

*1: Full phase real-time feedback control monitors movement of gear ratio at gear change, and controls oil

pressure in real-time to achieve the best gear ratio.

SHIFT PATTERN CONTROL
SHIFT PATTERN CONTROL : System Diagram

INFOID:0000000009267851

SHIFT PATTERN CONTROL : System Description

INFOID:0000000009267852

Shift pattern control automatically selects the shift pattern (such as road environment and driving style) suit-

able for the various situations so as to allow the vehicle to be driven efficiently and smoothly.

LOCK-UP CONTROL

JSDIA1637GB

JSDIA1636GB

TM-88

< SYSTEM DESCRIPTION >

[4AT: RE4F03C]

SYSTEM

LOCK-UP CONTROL : System Diagram

INFOID:0000000009267853

LOCK-UP CONTROL : System Description

INFOID:0000000009267854

• 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, and the torque converter clutch control valve engages or

releases the torque converter clutch piston.

Lock-up Operation Condition Table

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.

Smooth Lock-up Control

When shifting from the lock-up released state to the lock-up applied state, the current output to the torque con-

verter clutch solenoid is controlled with the TCM. In this way, when shifting to the lock-up applied state, the

torque converter clutch is temporarily set to the half-clutched state to reduce the shock.

Half-clutched State

JSDIA1638GB

JSDIA0847GB

Selector lever

“D” position

Gear position

4

3

2

Lock-up

×

×

–

Slip lock-up

×

×

×

SYSTEM

TM-89

< SYSTEM DESCRIPTION >

[4AT: RE4F03C]

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• The current output from the TCM to the torque converter clutch solenoid is varied to steadily increase the

torque converter clutch solenoid pressure.

In this way, the lock-up apply pressure gradually rises and while the torque converter clutch piston is put into

half-clutched states, the torque converter clutch piston operating pressure is increased and the coupling is

completed smoothly.

Slip Lock-up Control

• In the slip region, the torque converter clutch solenoid current is controlled with the TCM to put it into the

half-clutched state. This absorbs the engine torque fluctuation and lock-up operates from low speed.

This raises the fuel efficiency for 2GR, 3GR, and 4GR.