This paper describes the invention of an Adaptive Safety Monitoring Function at Jaguar Land Rover within the context of the development of a vehicle propulsion system according to the principles of ISO 26262. It outlines the way that conventional safety monitoring software is currently used to detect and mitigate faults in a propulsion control system. It then describes the typical challenges and drawbacks in developing such software. The paper then presents the theoretical principles behind how the proposed software algorithm could address these problems by adapting over time to the control software that it is monitoring. It explains the key challenge of ensuring safety by only adapting in a manner commensurate with the adaption of a driver’s mental model to a change in relationship between vehicle acceleration and accelerator pedal input. It describes some of the practical problems encountered and solutions found during algorithm development before concluding with an outlook towards potential commercial applications.