CONTINUOUSLY VARIABLE TRANSAXLE SYSTEM FAIL-SAFE CHART

  1. Description

    This function minimizes the loss of the Continuously Variable Transaxle (CVT) system functions when a malfunction occurs in a sensor or solenoid.

  2. Fail-safe

    1. Fail-safe control list:

      Malfunctioning Part

      Function

      Transmission revolution sensor (NIN)

      The ECM calculates the input shaft speed based on a signal from the turbine speed sensor to perform normal control.

      Transmission revolution sensor (NOUT)

      The ECM calculates the output shaft speed based on a signal from the speed sensor to perform normal control.

      Transmission revolution sensor (NT)

      The ECM calculates the turbine speed based on a signal from the primary pulley speed sensor to perform normal control.

      Shift solenoid valve DS1

      The ECM stops current to the solenoid. The gear ratio is adjusted to a lower ratio compared to the normal ratio.

      Shift solenoid valve DS2

      The ECM stops current to the solenoid. The gear ratio is adjusted to the highest ratio.

      Shift solenoid valve SL

      The ECM stops current to the solenoid to cancel lock-up. Moreover, forward and reverse clutch pressure control using shift solenoid valve SLS is canceled and forward and reverse clutch pressure control is performed only by controlling the oil pressure.

      Shift solenoid valve DSU

      The ECM stops current to the solenoid to completely cancel lock-up.

      Shift solenoid valve SLS

      The ECM stops current to the solenoid to maximize the secondary oil pressure in order to set the gear ratio to a predetermined value. Moreover, forward and reverse clutch pressure control using shift solenoid valve SLS is canceled and forward and reverse clutch pressure control is performed only by controlling the oil pressure.

      CVT fluid temperature sensor

      The ECM sets the fluid temperature to a predetermined value to perform normal control.