AUTOMATIC TRANSAXLE SYSTEM FAIL-SAFE CHART

  1. Fail-safe

    This function minimizes the loss of operation when any abnormality occurs in a sensor or solenoid.

    Table 1. Fail-safe Control List

    Malfunction Part

    Function

    Speed sensor NT (transmission revolution sensor)

    Shifting to only either 1st or 3rd gears is allowed.

    Speed sensor NC (transmission revolution sensor)

    • The counter gear speed is determined based on the signals from the skid control ECU (speed sensor signals).

    • Shifting between 1st to 4th gears is allowed.

    ATF temperature sensor

    Shifting between 1st to 4th gears is allowed.

    ECM power supply (voltage is low)

    When the vehicle is being driven in 6th gear, the transaxle is fixed in 6th gear. When being driven in any of the gears from 1st to 5th, the transaxle is fixed in 5th gear.

    CAN communication

    Shifting to only either 1st or 3rd gear is allowed.

    Knock sensor

    Shifting between 1st to 4th gear is allowed.

    Shift solenoid valve SL1, SL2, SL3 and SL4

    The current to the malfunctioning solenoid valve is cut off and control is performed by operating the other normal solenoid valves. (Shift controls in fail-safe mode are described in the table on the next page. For details, refer to Fail-Safe Control Chart)
    Table 2. Shift Solenoid Valve Operation when Normal

    Gear Position

    1st

    2nd

    3rd

    4th

    5th

    6th

    Shift Solenoid Valve SL1

    ON

    ON

    ON

    ON

    OFF

    OFF

    Shift Solenoid Valve SL2

    OFF

    OFF

    OFF

    ON

    ON

    ON

    Shift Solenoid Valve SL3

    OFF

    ON

    OFF

    OFF

    OFF

    ON

    Shift Solenoid Valve SL4

    OFF

    OFF

    ON

    OFF

    ON

    OFF
    Table 3. Fail-safe Control Chart

    Gear Position under Normal Conditions

    1st

    2nd

    3rd

    4th

    5th

    6th

    Shift Solenoid Valve SL1

    ON Malfunction (without Fail-safe Control)*

    1st

    2nd

    3rd

    4th

    4th

    4th

    OFF Malfunction (without Fail-safe Control)

    1st to N

    2nd to N

    3rd to N

    4th to N

    5th

    6th

    Fail-safe Control during OFF Malfunction

    Fixed in 3rd or 5th

    Shift Solenoid Valve SL2

    ON Malfunction (without Fail-safe Control)*

    1st to 4th

    2nd to 4th

    3rd to 4th

    4th

    5th

    6th

    OFF Malfunction (without Fail-safe Control)

    1st

    2nd

    3rd

    4th to 1st

    5th to N

    6th to N

    Fail-safe Control during OFF Malfunction

    Fixed in 2nd or 3rd

    Shift Solenoid Valve SL3

    ON Malfunction (without Fail-safe Control)*

    1st to 2nd

    2nd

    3rd

    4th

    5th

    6th

    OFF Malfunction (without Fail-safe Control)

    1st

    2nd to 1st

    3rd

    4th

    5th

    6th to N

    Fail-safe Control during OFF Malfunction

    Fixed in 3rd

    Shift Solenoid Valve SL4

    ON Malfunction (without Fail-safe Control)*

    3rd

    3rd

    3rd

    4th

    5th

    5th

    OFF Malfunction (without Fail-safe Control)

    1st

    2nd

    3rd to 1st

    4th

    5th to N

    6th

    Fail-safe Control during OFF Malfunction

    Fixed in 2nd

    *: Fail-safe control is not actuated when an ON malfunction occurs.