ECM Main Relay
The ECM main relay in the E60 is supplied with power by the ECM throughout the PT-CAN bus activity. Voltage is supplied to all the output actuators (which receive power via KL 87 from the relay) throughout the PT-CAN bus activity.
The activation of main relay (525i / 530i in E box, 545i in IVM) KL 87 is necessary for the function of the bit-serial data interface (BSD). The BSD is supplied with power by the ECM via KL 87 and a pull up resistor. The following components communicate with the ECM via the bit-serial data interface:
- Alternator
- Intelligent Battery Sensor