Not on the X250. The EPB is hydraulic and doesn’t work if you have a burst brake line.Could it be a safety thing? I'm thinking perhaps similar to the XF where you can pull and hold the EPB and it will slowly engage to slow you down (presumably if brakes have failed).
Mrs S has first hand experience of that ...
On the X260 and more modern models, the EPB is an electric motor on each rear calliper, so this may apply.
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