F30 keys not working

[Tomy321]

Hi guys appealing to the PH knowledge. Bmw 3 series both keys will not work to unlock the car the manual key will open the drivers door but the alarm will sound and no response from the stop start button. Popped to Halfords to pick up replacement fob batteries but they have advise diagnostics is required when changing a battery. I’ve changed one fob battery anyway and held to the steering column but no joy, any ideas?

[Elliot2000]

Flat battery is the first place to check.
It doesn’t sound like a key issue as the ignition would still come on with the key held against the steering column.

[Tomy321]

Thanks, tried jumping but still nothing waiting on a mechanic to come take a look