Alarm Fault

P38 (4.0 1998) showing "alarm fault" when I switch off. The alarm sets and the doors lock ok with the remote. Battery recently disconnected and re-fitted. Is this just one of these quirks that'll go away or is there a way of re-setting it? (I know the windows have to be re-set when the battery is interrupted)

I have managed to fix it. Method - Switch on ignition then off and disconnect battery within 17 seconds to prevent back up alarm activating. (It helps if the bonnet is open and the battery cover is already off for this bit.) Reconnect battery, start car, switch off, lock it by the remote and then put the key in the door lock and relock. The second bit re-synchronizes the key fob to the car as well. "Alarm Fault" no more.