Wondering how to unlock a Garmin Nuvi 55/56 or a 65/66 gps device? The process in’t overall difficult; however it requires a high degree of attention to avoid permanent damage to the navigation system.
Before going on with the unlock method and install free maps on Garmin Nuvi 55/56 or Nuvi 65/66 – we do not take any responsibility for bricking or any damage that may occur to your device during the process.
The current unlock method features risks that you will have to take.
Think twice if you are willing to unlock your gps; you may not, under any circumstances, take action against us if the method doesn’t work properly.
To unlock a Garmin Nuvi 55 or 56 then install the newest maps, you need to downgrade its firmware, that is, the navigation system software.
For model Nuvi 55/56 Part Number 006-B1697-00 specifically, you need version 3.20 of Garmin software, or older.
For Garmin Nuvi 65/66 Part Number 006-B1749-00 specifically, you need firmware version 3.40 or older.
Please abide to the above info.
In order to check your part number and software version, connect your Garmin gps to a PC and open GarminDevice.xml from the Garmin folder. The required information will be filled under the <Model> field.
If the firmware version doesn’t match the above data, cancel any attempt to unlock your device.
However, if the software version is a match, proceed to the next step.
Download the appropriate software for your Garmin Nuvi 55/56/ 65/66.
Connect your device to a computer and open the .System folder. Since t’s a hidden folder, it may not be automatically visible from your file explorer. To make it visible, follow these steps (applicable only for Windows OS).
Inside the .System folder, find and delete GUPDATE.GCD then replace it with the similar file you have downloaded from the link above.
After you have successfully replaced the file, disconnect the gps from your computer, then restart it. Once the Garmin will restart, it will ask to start updating its firmware version.
Agree with replacing the firmware and wait for the upgrade to be completed. Once it’s done, connect the GPS to your computer once again and open the GarminDevice.xml file with your web browser.
Inside, one of the following line should be visible, depending on your device model:
Nüvi 55/56 <SoftwareVersion>320</SoftwareVersion>
Nüvi 65/66 <SoftwareVersion>340</SoftwareVersion>
If the data shows a newer version, something went wrong; you must stop the unlock process at once.
However, if the firmware version is displayed correctly, it means you have successfully unlocked your Garmin Nuvi 55, 56, 65, or 66.
Next step is to add newer maps. Once a map has been added, it can only be unlocked with GimUnlock software (gimgunlock-0.03+MapSigPatch).
Download this software, copy the exe file in the same folder where the Garmin map is, then run it. Now your gps is ready to be used.
Of course, you can opt for buying the official map and classic update for this GPS model – a method that I highly recommend and which will provide a damage-proof functionality of your Garmin Nuvi navigation system.