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Fail-Safe Chart

  1. FAIL-SAFE CHART 

    This function minimizes the loss of the ECT functions when any malfunction occurs in a sensor or solenoid.

    1. Automatic Transmission Fluid (ATF) temperature sensor:

      When the ATF temperature sensor has a malfunction, O/D up shift is prohibited.

    2. Counter gear speed sensor NC (Speed sensor NC):

      When the counter gear speed sensor has a malfunction, O/D up shift is prohibited.

    3. Shift solenoid valve DSL:

      When the solenoid valve DSL has a malfunction, the current to the solenoid valve is stopped.

      This stops lock up control, then fuel economy decreases.

    4. Shift solenoid valve SL1, SL2 and S4:

    Fail-safe function:

    If either of the shift solenoid valve circuits develops an open or short, the ECM turns the other shift solenoid "ON" and "OFF" in order to shift into the gear positions shown in the table below.

    Manual shifting as shown in the following table must be done in case of a short circuit, the ECM stops sending the current to the short circuit solenoid.

    Even if starting the engine in the fail-safe mode, the gear position remains in the same position.

    FAIL-SAFE FUNCTION

    Normal Shift Solenoid Valve SL1 Shift Solenoid Valve SL2 Shift Solenoid Valve S4
    Gear Solenoid Valve Gear Solenoid Valve Gear Solenoid Valve Gear Solenoid Valve
    SL1 SL2 S4 SL1 SL2 S4 SL1 SL2 S4 SL1 SL2 S4
    1st ON ON OFF 2nd X ON OFF 3rd ON OFF X OFF 1st ON ON X
    2nd OFF ON OFF 2nd X ON OFF 3rd OFF X OFF 2nd OFF ON X
    3rd OFF OFF OFF 3rd X OFF ON OFF ON 3rd OFF X OFF 3rd OFF OFF X
    O/D OFF OFF ON 3rd X OFF ON ON O/D OFF X ON 3rd OFF OFF X
    FAIL-SAFE FUNCTION

    Shift Solenoid Valve SL1 and SL2 Shift Solenoid Valve SL1 and S4 Shift Solenoid Valve SL2 and S4 Shift Solenoid Valve SL1, SL2 and S4
    Gear Solenoid Valve Gear Solenoid Valve Gear Solenoid Valve Gear Solenoid Valve
    SL1 SL2 S4 SL1 SL2 S4 SL1 SL2 S4 SL1 SL2 S4
    3rd X X OFF 2nd X ON X 3rd ON OFF X X 3rd X X X
    3rd X X OFF 2nd X ON X 3rd OFF X X 3rd X X X
    3rd X X OFF 2nd X OFF ON X 3rd OFF X X 3rd X X X
    O/D X X ON 2nd X OFF ON X 3rd OFF X X 3rd X X X

    HINT:

    • E/B: Engine brake.
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