The GM338 uses a specific 8-pin RJ45 programming cable that plugs into the mic port. USB-to-Serial adapters are notorious for failing here; if possible, use a high-quality FTDI-chip cable. Driver Support:
If using a USB-to-Serial cable, ensure you have the correct Prolific or FTDI drivers installed for your PC to recognize the "COM Port." 4. Installation Steps
Protect your GM338. It’s a reliable radio—don’t let a repack kill it. motorola gm338 programming software download repack link
The radio is available in different versions based on its frequency band, which is critical to identify before you begin programming. The most common models are in the VHF (136-174 MHz) and UHF (403-470 MHz or 450-527 MHz) ranges, but low-band models also exist.
: This site maintains a collection of Motorola firmware and tools, though it often requires membership or specific contributions to access files. The GM338 uses a specific 8-pin RJ45 programming
: Most legacy Motorola CPS runs best on older versions of Windows (XP/7) or in compatibility mode. Software - Motorola Solutions Support
Immediately save an unaltered backup of the original file ( .DAT or .CP format). This original "codeplug" is your safety net if something goes wrong. Troubleshooting Common Software Errors Error Message / Issue Root Cause Cannot Open Port Wrong COM port selected or driver conflict. Change the port number in CPS or reinstall the USB driver. Radio Codeplug Not Supported Installation Steps
Protect your GM338
Often hosts technical documentation and versioning info for older professional series radios.
Note: Always make a backup of your original codeplug before making changes. 4. Alternative Solutions and Support
The Commercial Series CPS is often used for these models, though specific GM338 software like PMVN4039 is the official designation for the GM/GP series.