If some or all of the functionality of an ECU is temporarily not required, e.g., based on the vehicle state, the ECU can enter a “Pretended Networking” mode. In this mode, the MCU and/or peripherals are switched into a low-power mode.
前提：
Only the ICOM and the connected transceivers stay active. The ICOM generates a wakeup event, caused by, e.g. a received bus message, when the ECU needs to resume operation.
Depending on the ICOM implementation, message ID and payload of received messages may either be evaluated and filtered completely in hardware, require a callback mechanism in software.
效果：
Depending on the hardware implementation, the ICOM is also able to send messages. By using the ICOM to continue to send, e.g., status messages, other nodes that rely on that message are not affected by an ECU in Pretended Networking mode.
Furthermore, Pretended Networking aims at reducing wakeup response time, i.e., the time between a wakeup event and valid behavior of an ECU.
By using the ICOM to save relevant messages during activated Pretended Networking mode, the application has access to the last valid signal values directly after resuming operation. Therefore, the ECU can immediately respond to a user request after wakeup and does not have to wait until the according message is received again.