Circuit/System Description

WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.

The K56 Serial Data Gateway Module has the ability to learn the diagnostic addresses list of CAN control modules that are equipped on a vehicle. This learn will help the K56 Serial Data Gateway Module identify what CAN control modules are equipped on the vehicle and what CAN buses they are on. If the learn procedure is not done on a new K56 Serial Data Gateway Module, DTC U1977 will be set until the learn procedure is executed. If the learn is invalid due to control module internal malfunction or a K56 Serial Data Gateway Module swap, DTC U3000 42 or DTC U3002 56 will be set. If any of these DTCs sets, the K56 Serial Data Gateway Module will enable loss of communication for all CAN control modules. This will result in loss of communication DTCs being set against CAN control modules that are not equipped on the vehicle.