Fri Mar 27, 2026 7:01 pm
I have a GPSAMP 276C that I am attempting to change maps on from the City Select V6 CD that came with the unit at the time of purchase. The PC that was used to manage this device had a hard failure and became useless due to its age and operating system. Once the Garmin software was loaded onto a new Windows 10 machine and different maps were attempted to be loaded they are all now locked. Using the 25 digit code received from Garmin fails to unlock them with the present hardware configuration. Does anyone on this forum have any suggestions or experience with this model on a solution for unlocking these maps or what compatible US street maps are available for this now unsupported device by Garmin? I am new user and new to this form so please be patient. Thanks-Lcrane
Fri Mar 27, 2026 10:31 pm
Lcrane wrote:I have a GPSAMP 276C that I am attempting to change maps
Welcome to the forum.
I've never owned this device ,you can
[Please Register or Login to download file] to the device, there is also provisions for an
[Please Register or Login to download file] if not you could try downloading the Unlocked .gmap folder and use MapSource/BaseCamp to install a custom map set to your device.
[Please Register or Login to download file] [Please Register or Login to download file] Try this Unlocked test map for Huntsville,Birmingham,& Southern Alabama 68.0 MB.
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The firmware Change history shows
Added support for latest Garmin map technology.There are a few Unlocked smaller map sets available
new-maps/garmin-city-navigator-north-america-2027-t24793.htmlGPSMAP 276C software version 5.70 as of May 13, 2013
Change History
Changes made from version 5.60 to 5.70:
Support for new 010-10517-02 battery pack
Changes made from version 5.50 to 5.60:
Improved GPS satellite acquisition processing
Updated magnetic variation table with IGRF 2010 model
Changes made from version 5.40 to 5.50:
Added support for large NAND datacards
Improved power-up processing
Changes made from version 5.30 to 5.40:
Improved battery gauge accuracy
Changes made from version 5.20 to 5.30:
Improved compatibility with 512MB data card
Improved unit behavior when a blank data card is inserted
Improved display of battery charge level
Changes made from version 5.10 to 5.20:
Corrected address search operation with MPC maps.
Changes made from version 5.00 to 5.10:
Improved GPS satellite acquisition under certain conditions.
Added support for City Navigator update DVD.
Changes made from version 4.90 to 5.00:
Corrected external voltage alarm persistent behavior between power cycles.
Corrected state and country information for city searches.
Changes made from version 4.80 to 4.90:
Improved NMEA output.
Daylight saving changes for United States.
Added Mexican time zones.
Changes made from version 4.70 to 4.80:
Corrected 'persist' setting for external voltage alarm.
Improved ability to move user waypoints while editing a route.
Changes made from version 4.60 to 4.70:
Improved display of recommended route lines on marine charts.
Improved operation when moving user waypoints with the map cursor.
Corrected issue with changing usage mode from the Setup tab of the main menu.
Changes made from version 4.50 to 4.60:
Corrected issue that could cause 'WorldMap' series maps from being displayed.
Increased the number of characters allowed to display map zoom status.
Corrected text translations.
Clear trip data to correct issue with previously stored data.
Added Czech voice support.
Changes made from version 4.40 to 4.50:
Corrected issue in previous software revision that could cause some unit settings to be restored to defaults.
Corrected issue in previous software revision that could prevent the time zone from being changed.
Corrected issue that could cause the odometer field value to become inaccurate.
Corrected occasional unit shutdown during powerup.
Improved address search when using postal codes.
Updated text translations.
Changes made from version 4.30 to 4.40:
Changed distance displayed when measuring distance on the map page to use two digits of precision in marine mode.
Improved performance of Marine Services search.
Changes made from version 4.10 to 4.30:
Fixed SBAS compatibility issues with the Japanese MSAS system.
Changes made from version 4.00 to 4.10:
Improved display of lake depth contours.
Improved TracBack when using the entire track.
Improved GPS reception.
Changes made from version 3.70 to 4.00:
Added Iceland time zone.
Added support for latest Garmin map technology.
Added ability to select units used for displaying vertical speed.
Added ability to quickly select entire track for use with TracBack.
Improved voice guidance for road routes.
Improved Compass page in Automotive mode.
Improved Sonar page.
Improved Find menu.
Improved map selection when changing usage modes.
Corrected issue that could prevent some message log filter settings from being saved.
Corrected issue that could cause unit to shut down when using the Highway page.
Corrected issue with waypoint timestamp updates when transferring from Mapsource.
Corrected display of 'L' symbol in Turn data field.
Corrected display of 'Route Truncated' and similar messages when using USB.
Corrected display of cardinal direction on map page when measuring distance.
Corrected duplicate waypoint creation with GPWPL NMEA sentence input.
Corrected hilight movement problem on proximity waypoint page.
Corrected invalid display of Next Turn data field.
Changes made from version 3.60 to 3.70:
Corrected issues with address search.
Corrected issue with incorrect battery timer display.
Changes made from version 3.50 to 3.60:
Added output of NMEA APB sentence.
Corrected issue with restoring defaults on Com setup pages.
Corrected issue that could cause 'lock to road' setting in Automotive mode to be reset.
Corrected issue that could cause unit to power off when editing information on the Welcome setup page.
Changes made from version 3.40 to 3.50:
Improved visibility of airport runways on detailed maps.
Changes made from version 3.30 to 3.40:
Removed possibility of accidentally enabling 'Lock To Roads' when not in Automotive mode.
Added configurable field for UTC Time.
Improved Low Battery warning message.
Fixed nav alarms (next turn, arrival, off course, and anchor drag).
Changes made from version 3.20 to 3.30:
Added support for German tide stations.
Added support for more time zones.
Added support for NMEA BWC and extended DSC (DSE) sentences.
Added support for LakeMaster maps.
Added ability to select a particular map family when performing an address search.
Added ability to stop navigation from the Current Route page when in Automotive mode.
Improved accuracy of track log generation.
Improved readability of owner information text during powerup.
Improved USB transfers from MapSource.
Increased resolution of distance fields when in Marine mode.
Corrected shutdown that could occur when performing a TracBack in Automotive mode.
Corrected shutdown that could occur on the Line tab of the Map Setup page.
Corrected default Nearest Type selection on Position page.
Corrected display of map outlines.
Corrected functioning of Off-Course alarm.
Corrected date display on Celestial pages.
Improved display of street addresses in Find menu.
Changes made from version 3.10 to 3.20:
Fixed GPS unit-to-unit transfer of user data.
Fixed handling of display-options menu on the volume/backlight page.
Fixed waypoint category highlight error when dealing with a large category list.
Fixed problem where 'Searching' text would be displayed without results when performing a 'find'.
Added 'Show on Map' option to menu of the Tide Review page.
Added Sonar tab page to the Main Menu in Marine mode.
Improved readability of scroll bar arrows in Night mode.
Darkened Automotive mode Metro Area colors in Night mode.
Restored Find menu functionality when projecting a waypoint position.
When projecting a waypoint, the navigation context is now consistent.
Restored ability to download almanac data.
Added translations for the Greek language and updated other languages' translations.
Changes made from version 3.00 to 3.10:
Fixed problem that could cause the unit to turn off when the map heading line is enabled.
Fixed problem that would prevent changing the CDI scale using the zoom in/out keys in Marine mode.
Improved readability of map label text in Automotive mode.
Fixed the Sun & Moon page to update the date and time when using the 'Play' and 'Fast Forward' buttons.
Corrected 'find' operation behavior when a diacritic character is highligted.
Changed to use 24x24 custom waypoint symbol in connection with xImage.
Fixed functionality of projecting a waypoint by using the find menu.
Changes made from version 2.70 to 3.00:
Added support for remote sonar.
Added Marine DSC support.
Added new distance and speed unit, nautical (nm, kt, m).
Added Custom Avoids and Custom Road preferences to Road Routing setup.
Added calendar pages (day, week, and month) to the main menu.
Added column titles to the Add/Edit Vias page.
Added option to Point Review pages to 'Add to Current Route' when navigating an auto-route.
Added carpool lanes to avoid options in Road Routing setup.
Added auto backlight adjustment based on sunrise and sunset.
Added 'voice prompt' option to Sound setup; now provides ability to limit or prevent voice prompts.
Added output rate configuration to the Advanced NMEA setup page.
Added support for non-U.S. time zones.
Added GPS status to the list of configurable data fields.
Added support for selecting active track color.
Added choice to Routes Setup to transition waypoints by distance when navigating a manual route.
Added options to Volume/Light control page to go to Sound or Display setup menus.
Increased number of proximity waypoints to 100.
Turned on altitude recording in the active track log and saved tracks.
Fixed 'hide/show all' options on the Map Information page.
Fixed 'lock to road' option so unit remembers user's changes to it.
Popup text on the map page is positioned to avoid appearing under the cursor.
Fixed problem preventing user from editing the elevation of user waypoints.
Added ability to move waypoints in active manual routes.
Enabled Odometer as a configurable field in Marine mode.
Fixed address searches so number field will show all valid characters.
Fixed issue with Map setup that prevented the user for changing the Marine navaid symbol set.
Added support for auto CDI scale setting.
Modified Route list page to indicates an active route with an icon to the left of the route name.
Fixed highlight movement bug on proximity waypoints page.
Fixed shutdown when clearing active track log.
Fixed TracBack operation for large tracks.
Added Marine timer as a page layout for the Compass page.
Fixed functionality of deleting waypoints by category.
Added blank configuration field for 'map with overlay' layout.
Fixed issue with Indonesian Southern grid being located in the wrong area.
Updated language translations.
Fixed issue with displaying BlueChart data without water color.
Fixed shutdown when attempting to view the map families via the Data Card Information page.
Corrected problem with on route gotos.
Fixed problem with autoroute icon not showing up for all saved autoroutes.
Corrected problem with routes transferred from MapSource that show improper Distance and ETE values.
Fixed problem on the Active Route page that prevented the 'change data fields' option from working properly.
Corrected the way the date is displayed on the Calendar page to be consistent with other pages.
Fixed problem with display of the Find menu from the month tab of the calendar.
Fixed problem with TracBacks on large saved tracks.
Improved backlight auto-adjustment feature; this feature is now turned off by default.
Added standard European and Australian time zones.
Fixed Daylight Savings to work correctly in the Southern hemisphere.
Fixed shutdowns while driving in Automotive mode without a route active.
Fixed problem with entering dates on the Sun and Moon page.
Fixed the 'point review page' option 'append to route' to correctly add the point to the end of the selected route.
Fixed problem with Edit Via page displaying the pointer improperly.
Fixed shutdown when attempting to view the Log Filter tab on the main menu Message Tab.
Fixed problem with Calendar Day page not always displaying the items.
Simplified fuel timer control on the timer setup tab page.
Added range tick marks to heading line.
Changed metro area color to improve visibility.
Added cardinal direction indicator to Position page's 'nearest point' display.
Fixed unwanted characters that could appear in waypoint comment when saving a waypoint from an address.
Fixed possible display problems on the Saved Tracks page.
Fixed possible date display problems on Tide page.
Improved 'Proximity Alarm Memory is Full' message to appear everytime when trying to upload proximity waypoints to the unit once maximum limit has reached.
Changed Data Card Information page into Map Information page to include version information for all map data (basemap).
Changes made from version 2.60 to 2.70:
Fixed problem with display of hyphen when using German.
Fixed problem with Mapsource data transfer where unit would not accept maps and waypoints at the same time.
Fixed problem occurring in German, French, Spanish, Polish, and Portuguese. If the 276C was set to one of these languages listed, and you attempted to reset the max speed within the trip computer, the 276C would lock up.
Corrected problem when transitioning from the charging screen and attached to external power.
Improved handling and display of routes created on the PC and transferred to the unit.
Corrected problem on celestial pages which could cause the unit to shut down during cursor movement.
Unit no longer attempts to convert a Tracback route to a road route when switching from marine mode to automotive.
Changes made from version 2.50 to 2.60:
Increased maximum number of maps displayed.
Removed delay which sometimes occured when changing interface formats.
Fixed problem that may have occurred when swapping cards during a simulated route.
Fixed problem that occurred when using the elevation field in the overlay map view in automotive mode.
Added alert message to indicate when the user timer has expired.
Installation Instructions
Download the appropriate self-extracting archive file for your GPSMAP276C onto your hard drive.
Connect your GPSMAP276C to a free USB or serial port on your PC with the correct PC interface cable.
Turn on your GPSMAP276C. If you are using USB, ensure it shows USB as connected when the cable is plugged in. If you are using serial, ensure the Serail Data Format is set to 'Garmin Data Transfer' for the port you are using. You can find this setting on the 'Com 1' or 'Com 2' tab of the 'Setup' section of the Main Menu.
Open the self-extracting archive file and follow the instructions provided by the update application. During the upload, the GPSMAP276C's display will indicate 'Software Loading....' The upload process should take 1-10 minutes to complete, depending on interface used for update. When the upload is completed, the GPSMAP276C will reset itself and turn on normally.
Sun Mar 29, 2026 8:51 pm
Hello,
I have that device, you should install garmin basecamp, install that version that GarminNuvi shared on basecamp, and connect the device with the garmin card inside, via the mini usb and transfer just a part of it.
GarminNuvi this device uses a special card that is not visible by windows.
be sure to install the unlocked .gmap
Also osm maps work. same way to transfer to it.
Tue Mar 31, 2026 2:21 pm
Thanks to both of you for the support. I am still trying to figure out how to import or install the .img file GarminNuvi provided into the BaseCamp application. The software is recognizing my device but at this point I am stuck. Also a little uncomfortable with some of the pop-ups when attempting downloads. Please be patient this is a bit of a different process than I've used in the past.
Lcrane
Sat Apr 04, 2026 4:03 pm
GarminNuvi and Skinnie can you guys instruct me on how to load the file GarminNuvi sent me into BaseCamp for viewing and loading into the 276? I'm also looking for a way of unlocking the maps from an older V6 of City Select that came with the unit. Even though they are old maps they are still valid in most areas I travel but there are over 1000 ".img" files from the CD. It also appears due to Garmin's numerical naming convention they not cross or correlated to their respective areas or the Lat-Long. Thanks in advance for your patience and support once again.
Lcrane
Sat Apr 04, 2026 7:06 pm
Lcrane wrote:Please be patient this is a bit of a different process than I've used in the past.
OK both of us left you alone as requested.
Forget about trying to load the .img I created.
The CD's have been abandoned some time ago, what is used now and is compatible with your device is downloaded with Garmin Express. For North America this is City_Navigator_North_America_NT_2027_10.gmap which Mapsource or BaseCamp can be used to create custom maps set that you can choose the area dependent on your need and storage space on the device and a data card if installed.An Unlocked version of this .gmap folder has been Unlocked and will create Unlocked map sets.
1.Download and Install
[Please Register or Login to download file] or
[Please Register or Login to download file] on your PC.
2.Download
[Please Register or Login to download file] Only select the yellow folder
3.Unpack the 2 parts starting with part 1 your archive software will unpack part 2 automatically into City_Navigator_North_America_NT_2027_10.gmap.
4.Copy City_Navigator_North_America_NT_2027_10.gmap to C:\ProgramData\Garmin\Maps
5.Open MapSource (What I use) and create your map set and send it to your device.
[Please Register or Login to download file]
Sat Apr 04, 2026 9:50 pm
Followed your instructions and was able to download and install the new map files on my device. The only issue now is the Garmin proprietary memory card I have (128M) for the device with updated map data needs to have a little more capacity. But, I was able to get the maps for my area and a few others loaded with no issues. I remember seeing an article on Adventure Riders website of a guy in Russia that sold the correct type of memory I-C or chip that would allow you to have 1G of memory doubling the 512M card which was the largest Garmin offered for the 276/376C devices at the time. The only drawback it was as stated the I-C only. It was up to you, your abilities and tools available to swap the existing chip on the card to the new one. If you are aware of any such information on doing this process I would sure like to here from you. With all this said I would like to thank you guys for the support and a final solution in resolving this and the map loading issue. Hopefully it will allow me a few more years use of my existing GPS devices without the need to purchase a new one. Again thanks and have a Happy Easter.
Lcrane
Sat Apr 04, 2026 10:23 pm
Lcrane wrote: It was up to you, your abilities and tools available to swap the existing chip on the card to the new one. If you are aware of any such information on doing this process I would sure like to here from you.
I've not owned this device so never investigated a Chip upgrade, a 2Gb Data Card is $87.95, but you could buy a used Newer Garmin Automotive device with Lifetime map updates for that !
[Please Register or Login to download file] [Please Register or Login to download file]
Sun Apr 05, 2026 6:03 pm
You are probably right on a new device but I'll be 74 in August and still ride motorcycles. Knowing my riding days are growing to a close soon I'm just trying to get most I can from the 276C and 376C devices. Presently I have these two devices and two QWEST models. One of the quest has lost sensitivity to the satellites and pretty much tango uniform. The 276C was used in T-Mobile company truck before I retired in July of 2023 with just the state of Alabama, a couple of parts of Mississippi and little portion of Georgia. All this was on the 128MB card. The 276C is taking the place of the defective QWEST on one of my bikes. I bought the 512MB card for the 376C which has supported the areas I travel fine. The cost difference between a 512MB and the 2G appears to be app. $18. If these units will provide me with a few more years of operation I'll be happy. I want to again thank you guys and this forum site for the direction and support of a final resolution to being able to continue to use these devices. Take care and have a great Easter Sunday.
Lcrane
Sun Apr 05, 2026 11:45 pm
Lcrane wrote:The cost difference between a 512MB and the 2G appears to be app. $18. If these units will provide me with a few more years of operation I'll be happy. Lcrane
Hi, I wasn't sure of the application you were using it in, obviously it has a mounted home on your bike.
I don't have any history with GFixer the link I gave you for the Data cards, but I would ask about compatibility and FW requirements before purchasing.
Thu Apr 16, 2026 4:24 pm
One final comment from this discussion, I came across this about these older devices that use the data cards like the GPSMAP 276C.
"The Garmin GPSMAP 276C has a data card size limitation of 512 MB for map data, so using a larger card will not allow the device to read maps beyond this limit."
If there is a work around this I'd like to hear about how to overcome the limitation.
LC
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