Nissan Altima 2007-2012 Service Manual: Lock-up and select control system

System Diagram

System Description

• 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.

TORQUE CONVERTER CLUTCH AND SELECT CONTROL VALVE CONTROL

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 position, the engine speed, and the secondary pulley (output) revolution speed to lessen the shift shock.

Component Parts Location - Coupe

1. Control device assembly (Manual mode select switch and manual mode position select switch)

2. Accelerator pedal position (APP) sensor

3. Secondary speed sensor

4. CVT unit harness connector

5. TCM

6. Battery

7. Shift position indicator Manual mode indicator

Component Parts Location - Sedan

1. Control device assembly (Manual mode select switch and manual mode position select switch)

2. Accelerator pedal position (APP) sensor

3. Secondary speed sensor

4. CVT unit harness connector

5. TCM

6. Battery

7. Shift position indicator Manual mode indicator

Component Description

TRANSAXLE ASSEMBLY

EXCEPT TRANSAXLE ASSEMBLY

    Control system
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    Shift mechanism
    System Diagram NOTE: The gear ratio is set for every position separately. System Description In order to select the gear ratio which can obtain the driving force in accordance with driver's i ...

    Other materials:

    Normal operating condition
    Description FUEL CUT CONTROL (AT NO LOAD AND HIGH ENGINE SPEED) If the engine speed is above 1,800 rpm under no load (for example, the selector lever position is neutral and engine speed is over 1,800 rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies b ...

    Service data and specifications (SDS)
    General Specification CAUTION: • Use only Genuine NISSAN CVT Fluid NS-2. Do not mix with other fluid. • Using CVT fluid other than Genuine NISSAN CVT Fluid NS-2 will deteriorate in driveability and CVT durability, and may damage the CVT, which is not covered by the NISSAN new vehicle l ...

    Precaution
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