U121E-00-Lost Communication With Steering Wheel Cruise Control Switch
WARNING: This page is about a different car, the 2017 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
IF the Body Control Module (BCM), Adaptive Cruise Control (ACC) module, or Steering Column Control Module (SCCM) has any other lost communication DTCs present, perform those respective test first. If no other communication DTCs are set, refer to the SCCM diagnostics and perform the diagnostic procedure for U121E-00-Lost Communication With Steering Wheel Cruise Control Switch as if the DTC is active.