I have a c200k, and when i loke the car with the key the indicator lights keep on flashing rapidly until i open the lock again with the key. Occosionally the alarm goes of for no reason. the only way to lock the car is with emergency key. i have tried both sets of keys but the same thing happens

any help would be appreciated

 

Stab in the dark.
PSE located in the boot gone bad. This includes the ATA security system.
When you lock the door with key I don't think you arm the ATA. The USA system is different to the UK.
Unplug multipin connectors to PSE (pneumatic door locking system) and see if there is any (very slight) corrosion on the pins.(light blue staining)

NB. Does your interior light work automatically correctly?
Got any bulb out warnings?

Stuart.