Newer VWs & Audis (2018+)
Some newer vehicles may not permit scan tools to connect unless the hood is opened. If you are unable to connect:
- Remove the BlueDriver if inserted
- Open the hood
- Start the engine
- Plug in the BlueDriver and connect
Late 1990's & Early 2000's
In the 90s and early 2000's VW often ran the diagnostic system through the vehicle's radio. Some aftermarket stereos or harness adapters may inadvertently short the vehicle's diagnostic line to the battery, which will prevent all scan tool communication.
If your vehicle has an aftermarket stereo are you are unable to connect you may need to remove/disconnect the stereo and then attempt to connect again. If you are able to connect with the stereo/radio removed this confirms that your harness adapter is shorting the vehicle's diagnostic system to 12V.