Nissan Altima 2007-2012 Service Manual: Hydraulic control system

System Diagram

System Description

The hydraulic control mechanism consists of the oil pump directly driven by the engine, the hydraulic control valve that controls line pressure and transmission, and the input signal line.

LINE PRESSURE AND SECONDARY PRESSURE CONTROL

• 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 throttle position, the engine speed, the primary pulley (input) revolution speed, the secondary pulley (output) revolution 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 feedback.

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

    Mechanical system
    Cross-Sectional View 1. Converter housing 2. Driven sprocket 3. Chain 4. Reverse brake 5. Oil pump 6. Forward clutch 7. Planetary carrier 8. Primary pulley 9. Sun gear 10. Steel belt 11. ...

    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 ...

    Other materials:

    P0327, P0328 KS
    Description The knock sensor is attached to the cylinder block. It senses engine knocking using a piezoelectric element. A knocking vibration from the cylinder block is sensed as vibrational pressure. This pressure is converted into a voltage signal and sent to the ECM. DTC Logic DTC DETEC ...

    P0725 engine speed signal
    Description The engine speed signal is sent from the ECM to the TCM by CAN communication line. DTC Logic DTC DETECTION LOGIC DTC CONFIRMATION PROCEDURE CAUTION: Always drive vehicle at a safe speed. NOTE: If “DTC CONFIRMATION PROCEDURE” has been previously performed, always turn i ...

    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 intention and the vehicle condition, TCM monitors the driving conditions, such as the vehicle spee ...