Resetting your Garmin Street Pilot i3 may become necessary if the unit freezes or suddenly stops operating as it is intended. Resetting will force the operating system to reboot and reset all the basic settings within the GPS unit, clearing any faults or errors that have occurred. In some rare cases, resetting will not resolve the issue and the GPS must go to Garmin for repair. The address to send it to can be obtained by contacting Garmin customer support or from the owner's manual.
Press and hold the power button on the front of your Garmin to power it off. Allow it to sit for about a minute, then press the button and allow the unit to restart. If this does not reset the unit, continue to the next step.
Unplug the external power cord from the Garmin. Open the battery compartment on the back of the unit and remove the two AA batteries from the Garmin. Allow it to sit for about a minute.
Install the two AA batteries into the battery compartment, paying close attention to the negative and positive markings on the unit, and then install the battery door.
Plug the external power supply into the Garmin and push the power button, allowing the unit to reboot. If this does not fix you problem, you will need to contact Garmin about sending it in for service.