Systems, methods, and circuits for electrical pixel background current injection tests for lidar systems are described. Systems, methods, and circuits for electrical pixel timing pulse current injection tests for lidar systems are further described. Systems, methods, and circuits for or pixel photodiode health checking/testing using on-chip bias adjustment and passive photo-current imaging circuitry for lidar systems are also described. Embodiments can be used for specification of an Application Safety Integration Level (ASIL) in compliance with a safety standard such as ISO 26262 or the like.