As mentioned in a previous post, CARB requests that the SAE J1979 committee revise PID 0xF501 (data bytes B-F) descriptions in the DA, making them agnostic, by removing the reference to engine type (compression ignited, spark ignition). This would ensure that a system that is primarily used by one engine type but is introduced into another engine type will have the appropriate readiness bit available.
https://discuss.sae.org/t/readiness-for-turbo-in-gasoline-engines/35626/4?u=matthew.ortega