an unspecified impact level
Cause code ONA04
Plain-language explanation, impact details and live examples.
Last updated 21 May 2026, 17:05:35lavin
Announcement phrasing
Train operators typically phrase this cause as:
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Live trains referencing ONA04
Snapshot of services that mentioned this cause during the past 90 minutes and the next 3 hours.
Updated 21 May 2026, 17:05
We can't find any current trains referencing this cause.
Frequently asked questions about cause code ONA04
What does cause code ONA04 mean?
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How serious is cause code ONA04?
It is classified as an unspecified impact level.
Which trains are currently affected?
See the live examples above. The list refreshes every minute.