Pinpoint Test BW: U0256:00 Or U0557:82: Notes

Normal Operation and Fault Conditions

IPC DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Conditions
U0256:00	Lost Communication With Front Controls Interface Module "A": No Sub Type Information	Sets in continuous memory in the IPC if ambient air temperature (AAT) data messages received from the FCIM through the GWM are missing for 5 seconds or longer.
U0557:82	Invalid Data Received From Front Controls Interface Module "A": Alive/Sequence Counter Incorrect/Not Updated	Sets in continuous memory in the IPC if updated ambient air temperature (AAT) data messages received from the FCIM through the GWM are missing for 5 seconds or longer.

Possible Sources