Help! My GPS is in USB Mode!

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

We 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.

Located in GPS, GPS 101 on Oct 7, 2008