This program can extracts and replace WAV sounds from GUPDATE.GCD. Among these wav
sounds, we find the picture click, the camera in sight dong-dong, the speed alert,
etc... You can replace these sounds by new ones.

Credits: Thanks to neadrenalin for his insights on the GUPDATE.GCD structure.

Main Features

  • Play the predefined sounds in your Nuvi
  • Replace sounds like speed alert, camera in sight, etc... to something different including voices

Model Compatibility

GUpdateMod has been tested on Garmin models:
  • Nuvi 7x0
  • Nuvi 250 and all others having wav files inside the GCD.

Screen Shots



  • 1- Copy GUPDATE.GCD from your gps /Garmin directory to your computer.
  • 2- Start GUpdateMod and browse for this GUPDATE.GCD file you just copied.
  • 3- You should see some Wave buttons. 6 for the nuvi 760 and 250.
  • 4- You can click the Info button on the left to see the WAV information. You can also click "Play" to hear it.
  • 5- click on the "Save wave to disk" to backup the current sounds.
  • 6- click the "..." to replace the current "Wave x" sound with a new WAV. The new sound must have a size equal or smaller than the original one. It must also have similar characteristics: 1 channel mono, 16 bits per sampple, ... The sampling rate can be different.
  • 7- Once selected, you can click the info button to the right to see the sound info. Make sure it matches what is said in 6-. You can also play the sound by clicking play.
  • 8- Leave the "Replace with:" field empty to keep the current sound untouched.
  • 9- Browse to save the new GUPDATE.GCD file. DONT'T erase your original. You should always start this program with the original GUPDATE.GCD. Instead, write it to a different directory, but keep the same name.
  • 10- Now, you need to force your gps to update. For now, I only know this way. Let's say you just modified the GUPDATE.GCD for version 3.00. Force an update to version 3.10 using the proper update method. Reboot the GPS and let it take the update. Then, copy in the /garmin directory the new GUPDATE.GCD file you just modified and reboot the gps. It will tell you that the firmware version is smaller than the original. If you proceeed, the gps will reset your current settings. Say "yes". You will only lose your GPS settings, but not your POI and not your Favorites. Once done, your can try the new sounds

  • If the gps says the file GUPDATE.GCD is corrupted, something went wrong. Simply copy back the original GUPDATE.GCD or simply delete it and use the web updater.


Latest version: GUpdateMod

Revision History

Changes from v1.02 to v1.10
  • Added a tab to edit the legal warning at power-up. You can edit it only after opening an original GUPDATE.GCD. Otherwise you cannot if the file was alreay modified.

Changes from v1.01 to v1.02
  • no changes. Only updated readme and Help->About for latest version.

Changes from v1.00 to v1.01
  • better handling of block boundaries and data block identifier. Not 100% perfect but good enough for now.
  • Also corrected audio extraction problem. Extract them again with this version.

  • First version tested on the Nuvi 760 version 3.00
  • This version creates corrupted GCD on wave 1 & 6. OK for 2-5.