WHD.RG Firmware Update

Motorcycle Audio – WHD.RG Headunit Firmware Update (July 2026)

THIS UPDATE IS FOR SOUNDSTREAM WHD-RG INSTALLED IN 1998-2013 HARLEY-DAVIDSON ROAD GLIDE ONLY.  ATTEMPTING THIS UPDATE TO ANY OTHER MODEL OF HEADUNIT WILL CORRUPT THE CPU; “BRICK IT.” HEAD UNITS CORRUPTED BY ATTEMPTING AN INCORRECT FIRMWARE UPDATE ARE NOT COVERED BY THE MANUFACTURER’S WARRANTY.

Release notes:
- Updates CarPlay & Android Auto protocols
- Adds custom handlebar programming
- Corrects SiriusXM equalization

WARNING: Before attempting this update, please read these instructions carefully and don’t skip any steps, and be sure to use a blank flash drive (FAT32 format) from a reputable brand (SanDisk, Samsung, etc). If the flash drive is not empty, be sure to format it. You can find instructions on how to format a flash drive HERE.

A minimum 4GB or larger (32gb Max) USB Type-A flash drive with USB 2.0 or 3.0 is required. Larger flash drive sizes like 64gb or larger will not work. Using a flash drive with unknown USB specification will diminish data transfer and can corrupt the system processors. Use reliable name-brand USB flash drives. We use and recommend SanDisk Cruzer.

Update Instructions:

1. Download WHDRG_202607.zip from THIS LINK. 

2. Extract the contents of WHDRG_202607.zip. Copy ISPBOOOT.BIN & the UPDATE folder with ST25MCU.BIN inside to the blank USB Type-A flash drive.

3. Connect the flash drive to the USB Type-A input for WHD.RG. Usually installed inside one of the storage compartments.
   
   

4. Turn on the bike to accessory power.

5. After WHD.RG has completed its start-up sequence, the Main Menu should appear. If not, tap the Home icon in the top left corner, or Back arrow in the top right corner until the Main Menu is displayed. Tap the Settings gear icon on the shortcut bar.
   

6. Tap System Settings at the top of the settings list.

 7. Tap About at the bottom of the System Settings list. This will display the current software versions and serial number of your WHD.RG.

8. Select the Update button at center below Hardware version.

Note: If a pop-up window appears after pressing Update displaying “This data is not compatible,” double check the files on the flash drive are named correctly. The first file should be named ISPBOOOT.BIN, and a folder named UPDATE with a file inside it should be named ST25MCU.BIN. Any additional characters in the folder or file names may have caused this error message to appear. Also, delete any additional files that may have been previously hidden. Then, repeat steps 4-8. If the message appears again, contact Soundstream tech support: phone: 866-906-6866, e-mail: harley-tech@motorcycleaudio.com.

9. A pop-up with the new MCU version information should appear. The new MCU version should read WHD14+-WHDRG-260626; SOC version should be WHDRG-260701-01. Tap the Update button below.

10. After a moment, the MCU Update pop-up should appear, with its progress bar. When it completes, the screen may turn off or flash for a few moments.

11.  After several seconds, the SOC Update pop-up will appear with its progress bar. After it completes, WHD.RG will restart. It is ok to remove the flash drive from the USB input after WHD.RG has restarted.

12.  To confirm the update was successful, repeat steps 5-7. MCU version should now be WHDRG-260626; SOC version should now be WHDRG-260701-01.

If the SOC and MCU sequence do not match to the picture above, double check the files names are correct, ISPBOOOT.BIN, a folder named UPDATE with a file inside named ST25MCU.BIN. Correct the file name(s) and repeat steps 3-12. If trouble persists, contact Soundstream tech support: phone: 866-906-6866, e-mail: harley-tech@motorcycleaudio.com.