Before disconnecting the battery for service procedures, it is important to note that on a vehicle with power door locks, it is wise to remove the key from the ignition and keep it with you to avoid the possibility of it getting locked inside when the battery is reconnected. Devices known as "memory-savers" can be used to avoid some of these problems by providing sufficient current to maintain audio unit security codes, PCM memory, etc. To disconnect the battery, loosen the cable end bolt and disconnect the cable from the negative battery terminal, and isolate the cable end to prevent it from coming into accidental contact with the battery terminal.