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Help! My GPS is in USB Mode!

Oct
7
2008

We’ve been getting a number of people contacting us recently having trouble with their GPS going into “USB Mode” when it should be operating in the GPS mode. The issue can be difficult to track down but by investigating one piece at a time, we should be able to track down the issue. First, just what is “USB mode” or “computer mode”? Most of the time you will want to turn on your GPS and use it to navigate. But sometimes you might want to connect your GPS to your computer to add new features or to install updates. When the GPS is connected to your computer it will go into USB mode so that your computer can make changes to the filesystem of the GPS. The navigation part of your GPS will not be functional at this time so your computer can make the necessary changes. But sometimes, your GPS might go into USB mode when it shouldn’t. Here are some troubleshooting steps to help you figure out why.

Vehicle Electrical System

GPS USB ModeWe will start by taking a look at your vehicle’s electrical system as the possible source of the issue. While this is least likely to be the issue, we have seen it before. Unfortunately this is also the area that is the most difficult to diagnose and will likely require a car expert. The GPS decides if it should go into USB mode by looking at the power it senses. We have heard of cases where apparently a very week battery in the car caused some odd power to be sent to the GPS, resulting in the GPS going into USB mode. The owner replaced the battery in the car, and the GPS started working properly.

Power Adapter

Also known as the cigarette lighter, but we’ll call it the power adapter. If you have any other devices that can run from this power adapter, see if they work properly with their connectors. A good way to test if the issue is with the Vehicle Electrical System or the Power Adapter is to try the GPS and power cord in a different vehicle… If the GPS and power cord work fine in a different vehicle your issue is likely in one of these two areas and you might need to bring in a vehicle expert to diagnose the issue.

Power Cable

The most common source of the issue is with the power cable. We’ve seen issues where people have used Power Adapter splitters so they can plug in both their GPS and a cellular phone into the Power Adapter to charge both. In many cases the splitter caused an issue and made the GPS think it should go into USB mode. So make certain that you are plugging the GPS directly into the power cord and the power cord is plugged directly into the Power Adapter.

We’ve also seen cases of faulty power cables. This is more difficult to diagnose as you probably don’t have a second power cable of the same type to test with. You may however be able to borrow one from a friend or from the store you purchased the GPS from if nearby. Many power cables also have an inline fuse– it might be worth checking that as well. We’ve heard from people who replaced the fuse and the GPS started working properly again, although this scenario seems less likely.

Make certain you are also using the power cable that came with your GPS. Even if a different cable you have lying around might look similar, if it is designed for a different device the GPS might recognize the difference and force itself into USB mode.

Finally, make sure the cable is firmly plugged into both the GPS and the Power Adapter… I’ve seen cases where a little nudge has made a difference.

Reset the GPS

Many GPS devices come with a reset switch. Check with the manual that came with your GPS to find the proper operation of the reset switch, but most of the time it won’t cause any data loss on your GPS. We’ve seen examples where resetting the device fixed a few USB issues. And of course there could be an issue with the GPS itself, although this is also rare.

Most Common Scenario

Of the potential causes listed above, the most common ones are people using power splitters, damaged power adapters in the car, and not using the power cable that came with the GPS. Hopefully this will help you narrow down the issue, and get your GPS back into GPS mode.

11 Responses


  1. Helpful list, thanks!

    Thought I’d add another scenario though, at least once, possibly twice, I’ve encountered that TomTom-customers of mine have had corrupt internal and/or external (card) memory on their units.

    After reformatting the unit and sd-card the issue was resolved.

    Alexander - October 8th, 2008
  2. To Alexander: How do you format the unit and the card? Thanks

    Dave - October 11th, 2008
  3. Instructions can be found at the bottom of this support question: http://www.tomtom.com/2053

    Under the title of “What if the device still doesn’t start?” (follow the “Click here” link)

    Alexander - October 16th, 2008
  4. Hi,

    I am looking for a generic AC adapter for my Garmin 260 and a USB. I don’t want to pay the price for the Brand Name. What do I search for to ensure that I get a good generic for the AC adapter and USB cable to my computer.

    I think paying for all the european outlets on the ac adapter is not what i want since I dont travel overseas much.

    thanks Mary

    Mary - December 6th, 2009
    • Mary, if you don’t want to pay for a Garmin adapter then there isn’t anything you can to to ensure a third party adapter will be compatible.

      Tim - December 6th, 2009
  5. I have had my Nuvi 260 about 16 months. About a month ago I wanted to update my software so I had to unplug the car adapter from my Nuvi 260. I had a lot of trouble getting the USB cord out of the Nuvi. Ever since that time, I have had more and more trouble getting the car adapter or my computer adapter to stay snugly in the Garmin. If I wiggle it or press it real hard, it makes contact, but momentarily it loses contact again. Perhaps I caused it not to fit when I first disconnected my car charger. When I turn it on, it says “Low Battery” and turns itself back off. I love my Nuvi 260 – gives me the confidence to explore a little further from home!! Now I can’t even turn it on. What can I do?

    Sara - January 11th, 2010
  6. I had the same problem with my GARMIN 250W, when I used the 12V Cig lighter adapter to my motorcyle battery.

    On a GARMIN:
    You will need to hold down the lower left corner of the screen during power up for 15 seconds and it will go into regular GPS mode. The unit will bypass USB mode.

    I got this tip I got from the one a sales rep at http://www.GPScity.ca. I do not work there but I am very grateful how helpful they were so I feel a little plug is fair.

    I tried it and it works like a charm. Hope that helps!

    JP Burdett - April 28th, 2010
    • Thank you JP Burdett, that tip worked for me!!

      Paco - June 20th, 2010
      • Worked for me also!!! thanks!

        Frank - August 2nd, 2010
  7. Magellan RoadMate 1200
    On mine, it seems the 90 degree usb adapter is the key to the GPS mode/USB mode. With it in it will charge via power cord or usb cord (heck, even random USB cables/motorolla car chargers have worked in a pinch) and without it, defaults to USB mode. I’m assuming the 90degree adapter removes the 2 data pins from the USB connection but have not hooked up a voltage meter to verify that…

    FWIW if you have one of the winCE based devices like mine, you might want to google MioPocket to add a ton of apps/functionality to your device with a nice iPhone looking (not really iOS, just the look and feel) skin to it…

    jason - October 21st, 2010
  8. It seems that the pin out for a Garmin USB charging cable is slightly different from a regular USB data cable. Depending on your model, if you try to use a regular USB data cable you run into problem with USB mode, with Green lines looking for a software update at startup, and with the battery not changing. But what I want to know is where I can buy a UBS cable for my Garmin which the correct pin out for power mode. I have looked around amazon.co.uk but not found anything. I don’t want to rely on the 12v Garmin charger as I have in dashboard USB sockets on my car and it’s really frustrating not to be able to plug my divide into them. Any suggestions welcome!

    William - September 1st, 2011



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