This article describes how to update the Zune FM Transmitter v2 firmware to the current version.

Firmware is embedded software that controls the operation of a hardware device. The firmware is installed at the factory. However, you can typically upgrade the firmware for a piece of hardware when improvements become available.

To update your Zune FM Transmitter v2, follow these steps:

1.	Update the Zune device to the current Zune device software, which is also known as the Zune device firmware. To do this, connect the Zune device to a computer that has the current Zune software installed, and then update the device to the current device software. For more information, click the following article number to view the article in the Microsoft Knowledge Base: 926770 (http://support.microsoft.com/kb/926770/) How to update your Zune device
2.	With your vehicle parked, connect the FM transmitter to the DC outlet and make sure that your vehicle is providing power to the outlet. In many kinds of vehicles, you do this by putting the car ignition key in the "accessories" position.
3.	Connect the FM transmitter to the Zune device.
4.	When you receive the following message on the Zune device, press the center of the Zune pad: An update is available for this accessory. Please don't disconnect it until the update is complete. To update, press OK. If you do not receive this message, your transmitter is already updated to the current version.
5.	Several moments after the update is complete, your accessory will be available for use.

If you receive the message "An error occurred while updating the accessory. Make sure that the accessory is turned on, and then reconnect it to your Zune and press OK.", follow these steps:

1.	Disconnect the FM transmitter from the Zune device and from the DC outlet.
2.	Restart the Zune device. To do this, follow these steps: a. Set the Hold switch to the unlocked position. Note To make sure that the Hold switch is in the unlocked position, you may have to move the switch back and forth until the switch is in the correct position. b. Press and hold the Back button as you press the top of the Zune pad. c. Release the buttons when the Zune device begins to restart.
3.	Again try to update the FM transmitter firmware.

The following tables describes the latest version of the Zune device software and changes relevant to the Zune FM Transmitter v2:

Device software version	Improvement included
2.5	This version includes an update for the Zune FM Transmitter v2 that improves perceived volume.