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

2. Accelerator pedal position sensor

3. CVT unit harness connector

4. Primary speed sensor

5. Secondary speed sensor

6. PNP switch

7. TCM

8. Battery

9. Shift position indicator Manual mode indicator

Component Parts Location - Sedan

1. Control device assembly

2. Accelerator pedal position sensor

3. CVT unit harness connector

4. Primary speed sensor

5. Secondary speed sensor

6. PNP switch

7. TCM

8. Battery

9. Shift position indicator Manual mode indicator

Component Description

TRANSAXLE ASSEMBLY

EXCEPT TRANSAXLE ASSEMBLY

    Control system
    System Diagram System Description The CVT senses vehicle operating conditions through various sensors. It always controls the optimum shift position and reduces shifting and lock-up shocks. T ...

    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 ...

    Other materials:

    On-vehicle repair
    COMBINATION METER Removal and Installation REMOVAL 1. Open the fuse block cover, remove the instrument lower cover screw (A), then remove the instrument lower cover (1). • Disconnect the harness connectors. • Disconnect the aspirator tube. 2. Remove the steering column screws (A), ...

    Precaution
    Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT PRE-TENSIONER" The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along with a front seat belt, helps to reduce the risk or severity of injury to the driver and front ...

    P0451 evap control system pressure sensor
    Description The EVAP control system pressure sensor detects pressure in the purge line. The sensor output voltage to the ECM increases as pressure increases. DTC Logic DTC DETECTION LOGIC DTC CONFIRMATION PROCEDURE 1.PRECONDITIONING If DTC Confirmation Procedure has been previously cond ...