DTC C1242: G and Yaw Rate Sensor System (Abnormality of Longitudinal G Sensor Output Signal): Operation
WARNING: This page is about a different car, the 2015 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.
AWC-ECU receives the G and yaw rate sensor data from ASC-ECU via the CAN communication.