flipflap

Im trying to wire a alarm to my e36. It is not prewired for alarm. Im only want to get remote controlled central locking to work. The rest is not to important. When I apply +12v on pin 14 it locks. But to unlock I have to do more than +12v on pin 17, i have to trigger pin 17 and then pin 18. What am i doing wrong ? I do not understand how the states should be. Please help me! best regards Filip