You must have the corresponding TTS voice as well for ASR to work. If you have Portuguese_Brazilian_Raquel.vpm already, connect to WebUpdater or GarminExpress anyway to check for any other firmware/software updates and then clear NV after backing up your files if you want to restore favourites etc later. On reboot, make sure you select Brazil as the locale.

If the above doesn't help, post a screenshot showing the error message about ASR, or post the text of the message, along with info regarding at what point it occurs