I'm at a total loss and in need of dire help....Please.

My EPB module died a death. Screech, stuck on. Removed it and the gears are all dead.

Replaced the module, cables etc. Adjusted the new shoes as per the bible and jumped int he vehicle. Applied the brae button and it operates. However, it's as if it isn't operating for long enough to actually apply enough force to hold the vehicle.

I;ve used launch diagnostics to see if there's faults and there's nothing. Rechecked the adjustments, that's all good. It's just this issue with the motor not staying on long enough. Tried to engage service mode but it simply won't go into that so the only thing I have not done is the bedding in process.

Any info much appeciated. It's a 2012 Disco 4 automatic.