noun
self-checking; self-diagnosis
Used for checking or diagnosing one's own condition, often in medical, technical, or quality-control contexts.
定期的に自己検査を行うことが大切です。
It is important to perform self-checks regularly.
この機械には自己検査機能が付いています。
This machine has a self-diagnosis function.
自己診断 is more common for medical self-diagnosis, while 自己検査 is broader and includes non-medical self-checking.
Compound of 自己 (self) and 検査 (inspection, check). The exact historical derivation is uncertain, but the meaning is transparent from its components.