DIY diagnostic tools are devices or software that individuals can use to troubleshoot and identify issues in various systems, such as vehicles or home appliances. These tools often include handheld scanners, multimeters, and smartphone apps that provide real-time data and error codes, making it easier for users to understand problems without professional help. Many DIY diagnostic tools are designed for ease of use, allowing even those with minimal technical knowledge to perform basic diagnostics. For example, a OBD-II scanner can read engine codes in cars, while a digital multimeter can measure voltage and current in electrical systems, empowering users to take control of their repairs.