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Garmin Secrets

Discussion in 'Equipment' started by fish, Dec 2, 2002.

  1. fish

    fish Banned

    Joined:
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    Plucked off da BEEG list...no guarantees.

    Secret Startup Commands for Garmin handhelds
    There are several undocumented commands available, primarily at startup, on
    Garmin handheld receivers. This article will attempt to document some of the
    features available. I will try to document these in a universal way although
    details may differ depending on the unit you have. There are variations
    among models and among software releases within models. There is no attempt
    to provide 100% mapping to a particular model or release. Instead I have
    used a "try it" approach. I have documented what you may see and you will
    need to verify exactly what you did see. You may wish to print this out and
    check mark the features that are applicable to your unit.

    Note that these features are not documented by Garmin for a reason. They are
    generally for testing the device and are not intended for end users. The
    modes are not supported by Garmin and may cause you to lose data in your
    machines. Try this at your own risk!

    One major feature that is revealed when using these undocumented test modes
    is that there is a thermometer inside your Garmin unit. The intent of this
    thermometer is to compensate the internal time-of-day clock for changes in
    temperature which will cause the internal crystal to drift. To a lesser
    extent it is also used to adjust the contrast of the display screen for
    temperature changes. It will not measure ambient temperature except when the
    unit is first turned on since the internal temperature is changed due to the
    heating effects of the electronics in the unit. The thermometer based
    correction works by building a table of correction values that are then
    applied to the internal clock. This is only used to obtain an initial fix
    since after the fix the satellite data is used to keep the clock accurate.
    Similarly while you have a fix the accurate clock can be used to update the
    temperature data in the table which means the unit will compensate for aging
    parts and even the complete loss of the table.

    Special key startup sequences
    The three keyboard keys on the right side of the unit have special
    significance if held down while powering on the unit. These keys are
    generally called page, mark, and enter. On the GIII units the center key is
    call menu but for our purposes it behaves the same. On Street Pilots the
    equivalent keyboard names will have to be used. These are page, option, and
    enter. See below for etrex and emap startup sequences. Other Garmin units
    typically have some of these special modes as well although the key
    sequences may be different.

    Page - Holding the page key down while powering up the unit will cause an
    immediate forced cold start. On the street pilot this is the only way to
    observe the software revision level. On the G-III this is reported to lose
    the temperature compensation data.

    Mark - Holding the mark key down while powering up will totally reset unit.
    You will lose all user supplied data and preferences. The machine will be
    set back to factory defaults. Be careful, there is no warning message. All
    data will be lost!
    On some units this feature has been documented in the manual and will offer
    a warning message before erasing. However, some versions of software, even
    on these machines, do not offer the warning. Do not depend on the
    documentation here. Have everything of value backed up before trying this.
    The big plus of this feature is that this reset can fix problems with the
    unit that will avoid having to send it back to Garmin.

    Note that setting back to factory defaults means everything. You will not
    only lose things that you can backup but also settings that you cannot. For
    example the user defined datum, the user defined grid, any preferences and
    datums that you have set up, any customization of any kind. The leap second
    data will be gone. The Garmin waypoint will reappear if you have erased it.
    You will not have any of the tuning that was performed to calibrate your
    unit at Garmin so expect poor initial lockup performance. You will need to
    have a clear view of the sky and re-collect a full almanac. This takes about
    15 minutes.

    Enter - Hold the enter key down while powering up the unit will cause a test
    mode screen to appear. This test screen is used at Garmin in final testing
    and calibration of the unit. Warning! Do not use this screen if your unit
    can get a lock onto satellites. It is possible that a real satellite may
    spoof the test mode into recalibrating the unit with the wrong data. No
    permanent damage will be done but you may experience a little longer lockup
    times or may even have to do a total cold start to get it running again. You
    may also experience continued longer lockup times for awhile while the unit
    re-calibrates itself under use. You can read this document for a discussion
    of this issue from Garmin. If your unit has a removeable antenna then
    unplugging the antenna is a good way to ensure that no lock can be obtained.
    The test mode screen can appear automatically if the unit detects a failure
    during power up. You can use this mode to verify certain operations of the
    unit. For example hitting each key will cause the corresponding key in the
    display to darken. Hitting the enter key twice in a row (on some units it is
    the page key) will cause a graphic pixel test which could highlight any bad
    pixels in your display. Hitting the same key again will further test the
    display. Hitting the key one more time will return to the main test screen.
    One units that use the page key to perform this test you can use the quit
    key to perform the graphic test backwards. The power/lamp key will show both
    an indication and actually light the lamp.

    Other displayed entries are specific to internal tests performed in final
    test but the temperature (in Celsius), the internal and external battery
    voltages, and the gps time can be useful. On the G-III+ and 12Map this mode
    will also display the version number of the software which has been removed
    from the start up screen. On some units status of the power on diagnostics
    can be viewed here.

    While not obvious to an observer the test mode also starts the interface to
    emit PVT solutions in Garmin mode on units that support PVT output. Once
    started, this mode will continue even after a power off until you change it
    in the interface section by selecting "none".

    Emap Startup modes
    Emap supports the same 3 startup modes as other Garmin handhelds but some of
    the keys are different. Holding enter while powering up enters the test mode
    as described above. The temperature display is only in celcius and no
    external voltage is shown. You can run the visual screen diagnostics by
    holding down the esc key and then tap it to walk through all the screens.
    Holding down the esc key while powering up will reset the entire unit and
    you will lose all of your waypoints, routes, and tracklogs. There is a
    warning screen for this startup mode. Holding down the Find key and powering
    up forces the autolocate mode. It also places a couple of numbers in the
    upper right corner of the screen but I don't know how to interpret these
    numbers.
    Etrex Startup modes
    The etrex also has secret modes for test purposes. Hold the "up" and "page"
    keys and then press the "on/off" button to enter this screen. It behaves
    similar to the test mode described above and shows some information that is
    useful to the user. Note that is has been reported that the ROM test may
    show a false failure on this screen since a factory tester is not attached.
    You can run the key tests by pressing each of the keys. You can use the page
    key to cycle through all of the display tests. The screen shows the status
    of the power on diagnostics plus internal battery voltage and external if
    present. A clock display shows seconds, the revision level of the software
    is shown, and a thermometer reading shows the internal temperature in
    degrees Celsius.
    Hold the "up" and "enter" keys and then press the "on/off" button to reset
    the entire machine. You will receive a warning prompt. You can avoid this
    message using the sequence "Page" plus "Enter" plus "Up" and then press the
    "on/off" button. Hold the keys down for 5 seconds to perform the reset.

    The newer etrex units with the "Click Stick" use different keys to
    accomplish these tasks but the idea is the same. Holding the click stick
    down and then powering up will enter the test screen while holding the
    "page" key down and the "click stick" down and then powering up will reset
    the unit. You will be prompted with an "are you sure?" message. On these
    units holding down the "find" button in addition to the others will avoid
    the are you sure message. Hold the buttons for 5 seconds to clear the unit.

    Note that the extra key sequence may be an even bigger master reset but this
    is not clear to me.

    Garmin V
    To totally reset this unit hold the Zoom Out and Quit buttons down and then
    press the power on. All user data will be lost as will the almanac.

    76/Map 76
    The reported method to completely reset on of these units hold the "menu"
    key and the "quit" key down and then press the "power on" key. Hold for a
    full 7 seconds and then release. As with the other units all information
    will be lost and you will need to reload the almanac and all your saved user
    data to make the unit usable.

    For the 76S try this sequence to master reset it. Press and hold quit, Menu,
    and the rocker down key. Then press and release the power on key. release
    the rocker down and wait for the welcome display. Now release the quit and
    menu keys.

    Diagnostic Mode
    This may be the most useful of the secret modes available on some Garmin
    handhelds and for some users the hardest to access. Basically you start the
    Garmin normally by pressing the power button and while the opening screen is
    being display you must press each of the 4 arrow keys once in any order. If
    you accomplish this feat you will be rewarded with a quick switch to the
    status screen without waiting for the rest of the time-out. You should
    notice a -.- just under the satellite display to confirm your success. If it
    doesn't work then power down and try again. It takes a certain rhythm to be
    successful. This will not work on G-III or G-III+ units but most of the
    information is available on these units in normal mode. On G-II and G-II+
    units this method will only work if you have the unit set in portrait mode.
    The etrex and emap do not support this mode.

    The beauty of this mode is that you can leave the unit in this mode while
    using it. It adds a new Diagnostic menu item and more information in some of
    the displays.

    The -.- information on the status screen will be replaced with a HDOP
    setting once you have a fix. (HDOP stands for Horizontal Dilution of
    Precision and is a measure of the suitability of the geometry of available
    satellites to produce an accurate fix. Numbers below 2.0 mean that the fix
    is pretty good.) This is one of the factors used to calculate the estimated
    position error (epe) that appears at the top of the page. The EPE number is
    proprietary to Garmin but the HDOP number should be similar to one obtained
    for any unit since it only depends on the satellite geometry.

    Really old multiplex units may notice another difference on the status page.
    On some units the status bars are solid all of the time even when ephemeris
    data is not yet valid. On these units the hollow bars will appear only in
    Diagnostic mode. Unfortunately the new 12CX also has only solid bars and
    this mode doesn't fix them.

    The position page also has a new entry down near the clock. This is the
    current internal temperature in Fahrenheit degrees. On some units if you
    have set your preferences to metric this will be displayed in Celcius.

    Finally the menu page will have a new entry at the bottom. This "D" can be
    selected to enter the diagnostic page.

    The diagnostic page content will vary depending on which unit you have but
    will generally contain diagnostic pass/fail messages at the top of the
    screen, the elapsed time for the unit, internal software information, and
    finally battery voltage.

    On some units the elapsed time counter can be reset by hitting the enter key
    providing an additional timer for the unit. On units that already have an
    elapsed time meter in the normal position page then the one here cannot be
    reset with the enter key.

    On some units hitting the page key will provide information about the status
    of the last several shutdowns.
    Pressing quit will return you to the normal screens of the gps but realize
    the gps continues to work fine while you are looking at the diagnostic
    screen. If you hit goto or mark you will perform these functions.

    It is worth mentioning a little about the elapsed time meter. Generally this
    is expected to be the time since the last factory reset. However, it will be
    reset by the power-on/mark key sequence described above and it may be reset
    by some software upgrades.

    On some units the battery voltage includes both internal and external
    voltages. The internal voltage is indicated in .03 volt increments and seems
    to have this accuracy. The external voltage is indicated with the similar
    precision but does not have this accuracy. The external voltage has the
    following decimal setting for each whole voltage setting: .14, .29, .43,
    .57, .72, .86, and .00.

    Other easter eggs
    On some units, mostly older multiplex units, you can redisplay the world
    globe that appeared on the opening screen. Change to the map page and then
    hit the power-off button but stop before holding it down long enough to
    power the unit down. The globe will appear and you can control the speed of
    its spinning using the arrow keys.

    The III+ can display some icons that are not available on the icon menu.
    These are usually found in a downloaded map. For example the geographic
    place names are not available except when shown on the map. However you can
    use a trick to get these icons into you own waypoints. Find an entry using
    one of these waypoints on the screen and then press enter to convert it to a
    waypoint. You can now edit the waypoint values and name to be whatever you
    wish. These new icons will probably not be preserved when saved on a pc and
    re-entered since the pc program may not support them.

    Internal Diagnostic reports
    On the etrex models with the click stick you can reach an internal
    diagnostic message page which reports stack data and shutdown data. First
    change to the trip computer page and press the "zoom out" key, the "zoom in"
    key, and the "zoom out" key once again. This will turn on the diagnostic
    reports page.

    Has anybody found any more?

    Go to "Working with Garmin" Table of Contents


    revision
    first published 99/1/4/99
    added etrex 00/5/30
    add emap 00/6/2
    added III+ icon trick 00/7/5
    added new etrex models 01/4/9
    added 76 and alternate keys for etrex 01/12/22
    added V reset 02/03/09

    Dale DePriest
    #1