CONTINUOUSLY VARIABLE TRANSAXLE SYSTEM(for 8NR-FTS) SYSTEM DESCRIPTION

  1. SYSTEM DESCRIPTION

    1. The K313 Continuously Variable Transaxle is a fully electrohydraulically controlled steel belt type continuously variable transaxle. This is a highly efficient transaxle that is controlled in conjunction with the engine, contributing to enhanced fuel efficiency and quietness without shift shock. In addition, the continuously variable transaxle has the following features:

      • Diagnostic function

      • Fail-safe function when a malfunction occurs

  2. FUNCTION OF MAIN COMPONENTS

    1. The main components of the K313 CVT system are as follows:

      Component

      Outline

      Continuously Variable Transaxle Assembly

      Shift Solenoid Valve SC

      Used to switch control of the shift solenoid valve SLU between forward and reverse clutch control and lock-up clutch control.

      Shift Solenoid Valve SL

      Shift Solenoid Valve SLU

      Performs forward and reverse clutch control or lock-up clutch control depending on the state of the shift solenoid valves SC and SL.

      Shift Solenoid Valve SLP

      Controls the oil pressure of the primary pulley.

      Shift Solenoid Valve SLS

      Controls the oil pressure of the secondary pulley.

      Transmission Revolution Sensor (NIN)

      Detects the primary pulley speed.

      Transmission Revolution Sensor (NOUT)

      Detects the secondary pulley speed.

      Transmission Revolution Sensor (NT)

      Detects the input turbine speed.

      CVT Fluid Temperature Sensor

      Detects the CVT fluid temperature.

      Oil Pressure Sensor

      Detects the CVT oil pressure for belt clamping force.

      Stop Light Switch Assembly

      Detects the state of the brake pedal.

      Park/Neutral Position Switch Assembly

      Detects the position of the shift lever.

      Transmission Shift Switch Assembly (Shift Paddle Switch)*

      • Detects the driver's shift-up and shift-down operations in 7-speed sport sequential shiftmatic mode.

      • Operating this switch when the shift lever is in D changes the mode temporarily to 7-speed sport sequential shiftmatic mode.

      Shift Lock Control Unit Assembly

      Transmission Control Switch

      • Detects that the shift lever is in M.

      • Detects the driver's shift-up and shift-down operations when the shift lever is in M.

      Combination Meter Assembly

      Shift Position Indicator

      Indicates the shift lever position.

      Malfunction Indicator Lamp (MIL)

      Illuminates or blinks to alert the driver that the ECM has detected a malfunction.

      ECM

      • Performs electronic control of the CVT system.

      • When the ECM detects a malfunction, it performs diagnosis and memorizes the malfunctioning area.

      Airbag Sensor Assembly

      Yaw Rate Sensor

      Detects the vehicle's yaw rate.

      Acceleration Sensor

      Detects the vehicle's longitudinal and lateral acceleration and deceleration.

      Brake Actuator Assembly

      Skid Control ECU

      • Transmits the vehicle speed and the longitudinal acceleration signal to the ECM.

      • Transmits the operating states of the ABS and VSC to the ECM.

      Electric CVT Oil Pump (Oil Pump with Motor Assembly)

      Keeps CVT oil pressure at an adequate level while the stop and start system is operating.

      DLC3

      Used for connecting the diagnosis tool to read diagnostic trouble codes and ECM data.
      Tip:

      • The airbag sensor assembly incorporates the yaw rate sensor and acceleration sensor.

      • *: w/ Shift Paddle Switch

  3. OIL PUMP WITH MOTOR ASSEMBLY OPERATION CONTROL

    1. When the engine is stopped automatically by the stop and start system, the engine stop and start ECU operates the oil pump with motor assembly installed to the continuously variable transaxle to produce optimal CVT oil pressure for enhanced response of the continuously variable transaxle assembly and smooth start-off when the engine is automatically restarted.

      Tip:

      • Refer to the stop and start system operation conditions.

        Click hereClick here

      • The oil pump with motor assembly operates when the CVT oil temperature is between 25 and 111°C (77 and 231°F).

      • When the shift lever is in R, the engine will not be stopped by the stop and start system.

      Table 1. Oil Pump with Motor Assembly Operation

      Shift Lever Position

      P

      R

      N

      D or M

      Brake Pedal Depressed

      Operates

      Does not operate

      Operates

      Operates

      Brake Pedal Released

      Operates

      Does not operate

      Operates

      Operates → Does not operate*

      *: When the engine speed or vehicle speed reaches the threshold value, the oil pump with motor assembly will stop operating.