Power Supply And Grounds

The MS S52 control module receives the following power supply inputs:

• KL 30 - Constant Battery power. The ECM receives KL 30 from the battery to monitor the voltage level as an input and adjusts output functions if the battery voltage drops below a certain threshold.
• KL 15 - Ignition Key On. The MS S52 control module receives KL 15 for its wake up call and for activation of the engine control module relay.
• KL 15 - Main Relay (engine control relay) Power Supply. The ECM receives its operation from the main relay once the relay is energized by the ECM.

Fig 1: Input Signals/Components Power Supply And Ground Wiring Schematic

Courtesy of BMW OF NORTH AMERICA, INC.