Quote Originally Posted by Scavvy View Post
Used webupdate to get gupdate.gcd file, put it in garmin folder with nothing else. But it doesn't auto update when I put it in satnav and reboot it.
It won't update unless it's a later version than what's already loaded and as Garmin_Nuvi said nor will it update if you've used the C4 fw gupdate.gcd with a non-C4 device and vice versa. Also nor will it update if you've got the wrong HWID naming for the SD folder when trying to use TXT commands.

Another way to confirm the actual HWID on the device itself:
  • On "Where To/View Map" screen, press and hold battery symbol in top RH corner for ~5 or 6 seconds to open a hidden menu headed "SW Ver ...."
  • Press Next/lower RH corner repeatedly, about 9 times probably, until you see page "Version Information ...."
  • Press "Start Test" button
  • Press "More" button
  • First three lines after Boot BLK/X-Loader/System will show "Bxxxx-00 ....."
  • 4 numerals represented by xxxx is the HWID.

IMPORTANT WARNING: You must be absolutely sure to use the correct HWID's boot.bin to make ldr.bin for SD card's HWID folder. If you use the wrong one and it's incompatible with the device it will irretrievably HARD-BRICK it.