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Home › Nissan-Datsun › 2007 › Altima Base › Repair and Diagnosis › External Pages › Different car › Section 79 (Brake Control System (Hybrid)) › Function Diagnosis › Diagnosis System (VDC/TCS/Abs Control Unit) › CONSULT-III Function › Fail-Safe Chart › Fail-Safe Function

Fail-Safe Function

WARNING: This page is about a different car, the 2008 Nissan Altima. However, it is still accessible from the selected car via links, so may be relevant.
  1. If a malfunction occurs in the brake ECU, sensor signal, or actuator, rest normally operating parts will maintain brake control.
  2. When trouble occurs in the brake control system, the brake ECU turns the warning lamp ON, and prohibits ABS, TCS and VDC operations.

    ABS, EBD and BA system:

    MALFUNCTION REFERENCE

    Malfunction area Control method
    ABS system ABS, TCS and VDC control prohibited
    EBD system ABS, EBD, TCS and VDC control prohibited
    NOTE: A malfunction in the ABS system will result in an identical operation, with ABS, TCS and VDC system control prohibited.

    TCS and VDC system:

    MALFUNCTION REFERENCE

    Malfunction area Control method
    Hybrid control system (TCS and VDC systems) Before control: Disables control
    During control: Uses only the brakes to effect control
    Brake control system (TCS and VDC systems) Before control: Disables control
    During control: Disables control (by gradually ending control)
    NOTE: As for the TCS and VDC systems, different systems prohibit different controls depending on a malfunctioning part.
  3. The brake ECU prevents operation of a malfunctioning hydraulic pressure system and continues brake control with the normal hydraulic pressure system.
    NOTE:
    • If control of the Electronically Controlled Brake for any of the 4 wheels is prohibited, that wheel loses brake booster function or braking ability.
    • If one of the 4 wheels loses brake booster function, the feeling when depressing the brake pedal changes.
    • If control of the Electronically Controlled Brake for all wheels is prohibited, the 2 front wheels will lose brake booster function.
  4. If the brake control is stopped under such conditions as when trouble occurs with a hydraulic pressure source, the pressure generated in the master cylinder by the driver is applied to the wheel cylinder to ensure braking force.
  5. A power back-up until is built in as an additional power source to supply stable power to the system.
  6. If the regenerative brake alone does not operate under such conditions as a communication error with the HV ECU, control is switched so that all braking force is generated with the hydraulic pressure brake.
    MALFUNCTION REFERENCE

    Malfunction area Control method
    Brake ECU Normally operating parts will control brake and generate braking force
    Hydraulic pressure controlling parts Normally operating parts will control brake and generate braking force
    Hydraulic pressure source Braking force generate by the driver
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