Is it obligatory for a man who caused a car accident that led to his wife's death to fast for two consecutive months in the following scenarios: if he was driving too fast, or if he was asleep, or if he was not the primary cause of the accident?

Accidental killing in a car accident necessitates two things: expiation (kaffarah) upon the perpetrator, and a mitigated blood money (diyah) upon his 'aqilah (male relatives on the father's side), unless the heirs forgo it as charity. The expiation is the freeing of a believing slave, and if one cannot be found, then fasting for two consecutive months. However, if the driver took all safety precautions and was not negligent, and was surprised by something unavoidable, then there is no diyah or kaffarah upon him. But if he was negligent in any way, or exceeded the speed limit, or dozed off after feeling drowsy and did not stop, then diyah and kaffarah become obligatory upon him.