Direct Injection System Control: Notes

A high pressure fuel injector control module (HDEV) is used for each cylinder bank and is located in the engine compartment E box. The HDEV control module is supplied with system voltage from the ECM main relay (in the IVM). Data is transmitted from the ECMs to the HDEV control modules for each high pressure fuel injector via the Local-Can bus. The HDEVs activate the injectors individually.

NOTE: The high pressure fuel injectors are activated by the HDEV control modules with a voltage of 100 V and energized during the opening period with approx. 85 V.

Fig 1: Identifying Direct Injection Control System

Courtesy of BMW OF NORTH AMERICA, INC.

HDEV Control Modules: The HDEV control modules contain pulse width modulated final output stages with high performance capacitors to transform the system voltage up to 85 to 100 volts. Current flows in the output stages up to a specific cutoff value. This cutoff creates an induced voltage, e.g. 85 V, which is then charged to the high performance capacitors (boosters). The high pressure fuel injectors are actuated by this capacitor with 2.8 to 16 amps of current.