Thread: Flash D2 Delta firmware onto Fenix 5 Plus - anyone tried that?

From what I could gather, the devices are the same in terms of hardware:

Fenix 5S Plus = D2 Delta S
Fenix 5 Plus = D2 Delta
Fenix 5X Plus = D2 Delta PX

The 5 Plus has a HwId of 3110, latest firmware is 5.10, the D2 Delta 3197 with 3.00.

As I'm relatively new in the Garmin world, how can I force-flash the D2 firmware to the 5 Plus and maybe even change the HwId in the process? Also is it possible to change the serial number of the device?

EDIT: The Bluetooth/ANT+ firmware seems to be completely identical except the Fenix one reads 006B315300 where the D2 one has 006B326000 instead. Looks like internal ids/"part numbers".

EDIT2: Digging around with RGN_Tool, the firmwares for the Fenix (and D2 Delta) consist of a fw_0505.bin and an fw_all.bin. The fw_0505 of the D2 Delta Firmware 3.00 and the F5Plus firmware 4.20 are almost identical save for a few bits which might be flags to enable more features on the D2.

EDIT3: Interestingly enough, the GUPDATE.GCD for Rollback from a beta version to the earlier release version only contains the fw_all.bin for that release version. Might be a way to directly flash whatever version one likes.

EDIT4: The D2 Delta firmware seems to use the same SensorHub (006B301400), GPS (006B295700) and WiFi (006B219602) firmwares. Only ANT/BT is different - probably because of code to communicate with Garmin Aviation hardware.

EDIT5: Preboot mode on the Fenix 5 Plus: Turn off watch, hold START (top right) button while plugging the cable into the PC and KEEP HOLDING THE BUTTON. Preboot will be active as long as you hold that button. USB device ID: 091e:0003.

EDIT6: SUCCESS! Who would've thought that the bog standard WebUpdater is capable of uploading ANY file to the Fenix. Just get the D2Delta_300.gcn, convert it to rgn. (Might not be necessary.) Drag that onto the shortcut to WebUpdater, get the watch into preboot (and keep holding the button), send the file … and when it finished, release the button and enjoy your D2 Delta.