Digital engine electronics

In the new engine S63 TOP, the Digital Motor Electronics are;(DME) MEVD17.2.8 used, which are divided for use in master and slave.

The Digital Motor Electronics (DME) is wakened by the Car Access System (CAS) via the wake-up line (terminal 15 wake up). Sensors on the engine and vehicle deliver the input signals. The signals for activation of the actuators are calculated from the input signals and the setpoint values determined by means of a calculation model as well as the stored characteristic maps. The DME digital engine electronics module activates the actuators directly or via relays.

The after-run starts after terminal 15 OFF. The adaptation values are stored during the after-run. The DME master control unit sends a bus signal to signal that it is ready to assume the sleep mode. When all the control units involved have indicated they are ready to assume the sleep mode, the central gateway module (ZGM) issues a bus signal and the control units terminate communication 5 seconds later.

The following graphic shows the installation position of the Digital Engine Electronics (DME).

Fig 1: Identifying Digital Engine Electronics 2 (DME2)

Courtesy of BMW OF NORTH AMERICA, INC.

The Digital Motor Electronics (DME) is a bus user on the FlexRay, PT-CAN, PT-CAN2, and LIN bus. The Digital Motor Electronics (DME) are connected to the intelligent battery sensor and other parts via LIN bus on the vehicle. For example, the generator and electric auxiliary water pump are connected to the LIN bus on the engine. The Digital Motor Electronics (DME) with the S63 TOP is connected to the oil condition sensor via bit-serial data interface. The Digital Engine Electronics (DME) and Digital Engine Electronics 2 (DME2) are activated via the integrated supply module with terminal 30B. Terminal 30B is activated by the Car Access System (CAS). A second electric auxiliary water pump is connected to the LIN bus of the Digital Motor Electronics 2 (DME2) for the engine S63 TOP.

Additionally, there are a temperature sensor and an ambient pressure sensor on the printed circuit board in the Digital Motor Electronics (DME). The temperature sensor monitors the thermal condition of the components in the DME digital engine electronics system. The ambient pressure is needed for the diagnosis and verification of sensor signals.

Both control units are cooled with coolant in the charge air cooling circuit.

The graphic below shows the cooling circuit to cool the Digital Motor Electronics (DME) and charge air cooler.

Fig 2: Digital Motor Electronics - Circuit Diagram

Courtesy of BMW OF NORTH AMERICA, INC.

The correct connection of coolant hoses without kinks is important to warrant the cooling for the Digital Motor Electronics (DME).