Purpose of the System

Purpose Of The System

This module describes the technical changes that have been made to the Power Module relevant to fault codes and diagnostic service procedures. You should be familiar with the basic operation covered in the E65 Complete Vehicle course (ST042). Additional information is now available for:
- Closed circuit current monitoring
- Check Control messages
- Battery replacement

The Power Module ensures that the battery charge level is maintained when the engine is running and when the vehicle is at rest. The Power Module is also responsible for maintaining the power supply (in the event of faults in the electrical system) to important vehicle systems by disconnecting lower priority circuits.

Power Module Functions
- Optimum charging.
- Load-circuit peak reduction.
- Shut-down of auxiliary consumer circuits in the event of low voltage.
- Closed circuit current monitoring.
- Distribution mode.
- Automatic electrical system isolation.
- Load output.
- Electronic fuses.
- Central battery voltage notification.
- Rear window defogger output.
- Interior lighting control.
- Trunk lid and fuel filler flap control.
- Data memory storage.
- Emergency-mode functions.
- Check Control messages.
- Diagnosis.

System Components
- Power Supply circuit
- Fuses
- Power Module
- Electronic battery master switch
- High-current sockets
- Inputs
- Outputs connected to electronic battery master switch
- Outputs not connected to electronic battery master switch
- Electronic control unit