Thread: Nuvi 54LM: Shutdowns in ~2 secs after reflash

Thanks for advice. Here's how it panned out.

1. Tried with 3 different cables.
2. Tried flashing from Win 10 RS2 64 bit and Win 7 32 bit
3. Have the Garmin usb drivers installed.
4. GarminCure3 always updates successfully both Cure and Original in preboot mode.
6. Tried flashing with GCD 350, 360, 370, 380, 390 --> 400 versions.
5. Flashed a SDCard to FAT32 and loaded an unlocked map to sdcard\Garmin\gmapsupp.img location. Nuvi 54LM is able to load this map on the SDCard. So we have a work around to continue to use the GPS. Many thanks for this tip!

The issue am currently facing is:

a. Nuvi 54LM when connected to a PC will not go into mass transfer mode. Can't see the Nuvi or SD card storage from Windows Disk Management or explorer. How can I force mass transfer mode to view its drive contents?

b. After I flash this device using GarminCure3 and look at the inventory page, the CN North America NT 2018.20 detail goes from 0% to checksum 1E96DB4 in a couple of minutes. At bootup I get a "Cannot authenticate maps" for the North America NT 2018 map which should be part of this lifetime update Nuvi 54LM device. But this map does not load post bootup.

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Thanks again for all the help!