All 2005 Mercedes-Benz C-Class model vehicles come standard with the Bluetooth Connectivity function. All you need to do to install your Bluetooth-compatible phone with the connectivity in your C-Class is follow the instructions in your 2005 C-Class owner's manual or check out the Bluetooth Connectivity page on the Mercedes-Benz website. The process is fairly simple and takes only a few minutes when done correctly.
Verify that your cell phone is Bluetooth compatible by checking the user's handbook that came with the phone. If your phone is not Bluetooth capable, it cannot be connected to your Mercedes C-Class.
Get into your car with your phone. Push the "Phone" button on your radio control settings in your Mercedes and select "Bluetooth Phones" from the displayed list.
Navigate through the system as the screens change. First, select "Options," then "External Authorization." This allows your Mercedes to locate the Bluetooth device for your cell phone. Pairing has now begun.
Locate the "Bluetooth" option on your cell phone and turn the mode from "Off" to "On." Wait while your phone discovers the other Bluetooth devices in range. When the choice "MB Bluetooth" appears on your phone screen, select it.
Click "Yes" when your phone asks if you want to authorise MB Bluetooth to connect with your cell. Your Mercedes system will then ask you to choose a four- to six-digit numeric code of your choice to input in both your car and your cell phone. Speak the code to your car using the voice-activated process, and input the code into your phone using the numeric keypad. Select the "Connect" option on your phone once you've confirmed and entered your pass code. Your phone will take a few minutes to connect to your car. If successful, the word "Paired" will appear on both your car's radio screen and your phone's screen.
If you are using the Mercedes website connectivity instructions, follow the link in the References section and click on the phone that you currently own to download a copy of the connection instructions to your computer.