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:

    Push-button ignition switch positions
    LOCK (Normal parking position): The ignition switch can only be locked in this position. The ignition switch will be unlocked when it is pushed to the ACC position while carrying the Intelligent Key. The ignition switch will lock when any door is opened or closed with the ignition switche ...

    ASCD Brake switch
    Description When the brake pedal is depressed, ASCD brake switch is turned OFF and stop lamp switch is turned ON. ECM detects the state of the brake pedal by those two types of input (ON/OFF signal). Refer to EC-1090, "System Diagram" for the ASCD function. Component Function C ...

    P0826 manual mode switch
    Description Manual mode switch is installed in shift control device. The manual mode switch sends shift up and shift down switch signals to TCM with CAN communication. TCM sends the switch signals to combination meter via CAN communication line. Then manual mode switch position is indicat ...