Components of the System: BC1

The internal relays are activated based on inputs received by the BC1. The relays are activated on a time basis dependent upon battery voltage.

Polarity to the locking motors is reversed at the BC1 to drive them in both directions.

BC1 CENTRAL LOCKING RELAY ACTIVATION TIME

Battery voltage (V)	<9	<10	<11	<12	<13	<14	<15	<15
Relay on Time (sec)	1.0	0.85	0.7	0.6	0.5	0.45	0.4	0.4

Fig 1: Door Latch With Integral Locking Motors

Courtesy of BMW OF NORTH AMERICA, INC.

NOTE: Internal door lock relays are always driven for the maximum time based on battery voltage, except in the event of a sticking relay. If a sticking Relay is detected the BC1 will register a fault code and drive the companion relay so all outputs are at equal potential and the locking motor stops.