Fault diagnosis methodologies for analog circuits lag far behind those for their digital counterparts. In this paper, we show how the generic Symmetry-based Built-In Self-Test (BIST) (or SymBIST), originally proposed for defect-oriented postmanufacturing test and on-line test, can be seamlessly reused for the purpose of diagnosis. BIST can offer better insights into the circuit and, thereby, can assist diagnosis towards resolving ambiguity groups. Using SymBIST we demonstrate high diagnosis resolution and fast diagnosis cycle for an industrial Successive Approximation Register (SAR) Analog-to-Digital Converter (ADC).