Method and apparatus for providing a leak detection circuit for a data monitoring and management system using the guard trace of a glucose sensor by applying a leak detection test signal to determine whether a leakage current is present is provided. The leak detection circuit may include an interface circuit, such as a capacitor, coupled to the guard trace to detect the leakage current when the leak detection test signal is applied to the guard trace, such that the user or patient using the data monitoring and management system, such as glucose monitoring systems, is notified of a failed sensor and prompted to replace the sensor.