WARNING: This page is about a different car, the 2008 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
If DTC B2400 is set, diagnose the CAN bus lines.
When replacing the ECU, always check that the communication circuit is normal.
Fig 1: Receiver Antenna Module And KOS-ECU - Circuit Diagram