As the global population rises, a fundamental shift away from fossil fuels is urgently required to satisfy the increasing energy demand of the modern world. Not only is the extraction and combustion of fossil fuels detrimental to the environment due to their associated greenhouse gas emissions, but sources of oil, coal, and natural gas are becoming increasingly expensive and difficult to extract. Polymer electrolyte fuel cells (PEFCs) have the potential to play a crucial role in solving some of these issues, producing no harmful emissions during their operation. They are cleaner and more efficient than traditional combustion engines. However, one of the largest factors limiting the commercial ubiquity of PEFCs is their high likelihood of faults. For the operation to remain stable, PEFCs must be controlled within a narrow range of operating conditions; deviation from these conditions leads to enhanced degradation and performance losses . Although some faults can be corrected via control action (recoverable faults), certain faults can only be rectified via the complete replacement of components (permanent faults). Water management is a critical issue for PEFCs, accounting for over 50% of all failures, and can be divided into flooding and drying faults . Drying reduces the ionic conductivity of the membrane and, in addition to performance decline, can also result in permanent membrane degradation since it becomes more brittle and prone to cracks and pinholes . Hence, it should be noted that if recoverable faults are not detected in time, their status will exacerbate, often leading to permanent faults and damage to the materials in the fuel cell. There is a clear motivation for novel fault diagnosis strategies to identify and rectify faults before they irreversibly worsen.