Circuit/System Description
WARNING: This page is about a different car, the 2020 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.
The K124 Image Processing Module is constantly sending a serial data message to the K20 Engine Control Module requesting engine speed or torque reduction. The K20 Engine Control Module sets DTC P15F6 when it detects a discrepancy in the structure of the message causing the integrity of the message to be questioned. An intermittent fault in the serial data circuits will cause the engine control module to set DTC P15F6.