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Master Warning, ABS, (!), and Hybrid Vehicle Warning icon

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Patrick Wong, May 27, 2009.

  1. PDWhite

    PDWhite Junior Member

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    Shawn,

    I have a very good handle on the computer firmware aspect of this discussion. :nerd:

    From a microprocessor's point of view, there is no difference between firmware, program code, and configuration data. The configuration data comprises BIOS settings that you refer to.

    The only real difference is that the BIOS and its default values normally reside in a static, or non-volatile, area whereas current BIOS configuration settings usually live in a separate volatile data area. (These areas are sometimes referred to as the “pure†and “impure†memory areas, respectively.)

    When the BIOS is reset to “default†the stored default/static values are written into the volatile area and are read as current configuration on the next boot-up.

    On many of today’s system boards with overclocking capabilities, it is very possible to come up with combinations of config settings that will not fly. Normally, a hard reset will force the next restart to clear the configuration area reload the defaults, but not always.

    There a number of possible reasons for this. (It is not useful to go into the details here.) Suffice to say that it is possible for the configuration area and even the non-volatile BIOS areas to become corrupted by an unexpectedly bad configuration or a crash. In such cases, it may be necessary to re-flash the BIOS to clean up the mess.

    Running the flash software will wipe the memory area clean, before writing a new BIOS image into it and restoring the default settings. This is why re-flashing the inverter firmware can be a good precaution to take.

    As a result, I have just passed the "SSC 50P" suggestion on to the service manager at the dealer repairing my car, hoping it will be part of the coolant pump repair job.

    -pdw :)
     
  2. hobbit

    hobbit Senior Member

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    If you're talking about the hybrid ECU's flash, that's in the
    hybrid ECU and nowhere near the inverter. There's some custom
    iron in the inverter slave board but it's relatively simple.
    And probably designed to be quite heat-immune.
    .
    _H*
     
  3. jayman

    jayman Senior Member

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    I wonder if any voltage spikes/surges could cause problems with the rewrittable portion of the ECM?