AUTOMATIC TRANSAXLE SYSTEM FAIL-SAFE CHART


  1. Fail-safe

    The fail-safe function minimizes the loss of operation when a malfunction occurs in a sensor or solenoid.

    Fail-safe Control List
    Malfunctioning Part Function
    Input speed sensor NT (transmission revolution sensor) Shifting to only 1st or 3rd gear is allowed.
    Output speed sensor NC (transmission revolution sensor)

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

    • Shifting between 1st to 4th gear is allowed.
    ATF temperature sensor Shifting between 1st to 4th gear 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 1st to 5th gear, the transaxle is fixed in 5th gear.
    CAN communication Shifting to only 1st or 3rd gear is allowed.
    Knock sensor Shifting between 1st to 4th gear is allowed.
    Solenoid (SL1, SL2, SL3 and SL4) valves 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.)
    Solenoid Valve Operation when Normal
    Gear Position 1st 2nd 3rd 4th 5th 6th
    Solenoid (SL1) Valve ON ON ON ON OFF OFF
    Solenoid (SL2) Valve OFF OFF OFF ON ON ON
    Solenoid (SL3) Valve OFF ON OFF OFF OFF ON
    Solenoid (SL4) Valve OFF OFF ON OFF ON OFF
    Fail-safe Control Chart
    Gear Position under Normal Conditions 1st 2nd 3rd 4th 5th 6th
    Solenoid (SL1) Valve 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
    Solenoid (SL2) Valve 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
    Solenoid (SL3) Valve 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
    Solenoid (SL4) Valve 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 function does not operate when an ON malfunction occurs.