WARNING: Attempting what is written in this post may render your zumo 665 an expensive paper weight or you may have to pay Garmin for an expensive repair, or aliens may come and take you away to their planet for probing to determine why you tried this. Reader beware!
Being a tech geek I always like to have the latest features and fixes on my electronic devices. To that end, when Garmin released firmware 2.90 for my GPS I eagerly went to the bike to retrieve the unit and plugged it in and proceeded to perform the update through the Garmin myDashboard. Before I knew it I had version 2.90 installed and ready to go.
And then I rode the Heart of Texas Unique Bonus ride where I found a very serious problem. The Zumo wouldn’t reliably make/receive phone calls. The first call might work but then subsequent calls would not. Or maybe the first 2 or 3 attempts would fail with no audio but the call would connect. Sometimes this could be fixed by rebooting the phone, or rebooting the Zumo, or both. Maybe removing the pairing and starting over. This is not the sort of thing you want to hassle with while on a motorcycle and certainly not the sort of issue you want during a rally.
So today, I decided to call Garmin with a laundry list of problems. Many focused on the bluetooth issues. After a 20 minute wait I finally spoke to a customer rep named John. He was exceptionally polite and I was determined not to lose my temper as I kept reminding myself that he was likely a helpless tech support worker who could no more really fix a complicated programming issue than he could route a monkey to the moon. But I was hoping he had some helpful information that could point me in the right direction.
In the end, even though the bluetooth problems didn’t occur until AFTER I upgraded to firmware version 2.90 he said there was nothing he could do about it since my Samsung Galaxy Nexus and ATT Z431 phones were not supported devices. He went on to say that bluetooth is not a standardized protocol and manufacturers just do what they want so there’s no way Garmin can be expected to work with every phone. When I heard this I was dumbfounded. I’ve heard support desk people say some really stupid things but this took the cake. Bluetooth wasn’t a standardized protocol, I wonder what Jabra, Motorola or any of the other thousands of headset manufacturers would say to that.
Next I asked if there was a way to revert the firmware to an older release. He told me NO, absolutely not. The upgrades are permanent. At this point I recognized I was talking to someone with far too little training or he was just plain stupid. So I switched gears to deal with a mount issue which in part has to do with corrosion. He agreed to replace the mount under warranty. At that point I concluded the call.
Now, I turned to Google and the hacker community. It turns out you can revert to an older firmware version on the Zumo 665 pretty easily if you can find the update file known as a GCD file. The only trick is that Garmin hides the files because they don’t want you downloading them directly. Good old “Security through obscurity”. But that won’t stop the dedicated individuals out there.
I found a wonderful site called noeman.org, they talk about all sorts of electronic devices like cell phones, laptops, GPSes and more. And they have a fantastic forum with some really smart people. I found this post where they list the last 4 versions of updates for the 665. You need to register before you can see the links but registration is free and easy.
The next question I had to answer was how to apply the update in order to revert my version 2.90 unit to version 2.80. The solution turned out to be rather simple. Find the Garmin WebUpdater.exe program on your hard drive. On my computer, it was located at
With the Zumo plugged into the computer already I just drug the zumo665_GCDFile__208.gcd file over the webupdater executable and released the mouse button. The webupdater started and after clicking next a couple of times it began installing version 2.80 firmware onto my Zumo.
Once the updater was finished I unplugged the GPS and put the battery cover back on. The unit detected that I was trying to install an older version of the firmware and warned that my user settings would be deleted. I agreed and pressed YES. After the update finished, the unit rebooted and I was prompted for set up information just as I would be if I had taken a brand new unit out of the box. Interestingly my home location was not lost during the upgrade while other user settings were including bluetooth pairings.
I’m now running version 2.80 and will test it for a few days. In my initial tests I noticed it also suffers from a hang up problem where you press the “End Call” button the GPS and the phone drops the call but the GPS isn’t aware of the call ending. You have to press it a second time. I don’t believe this was present in version 2.70. However, of the dozen or so test calls I placed, each and everyone of them successfully connected on the first try. I’m making progress by going backwards.
So that’s how I managed to revert my Zumo 665 back to an older working firmware release. YMMV.
The next step is to redo the XM weather alerts so they are nearly muted.