MSM DTC U1255: Generic Loss Of Serial Communications: Description

When ignition switch is in RUN position, all modules that communicate over the class 2 serial data bus send a State Of Health (SOH) message every 5 seconds to ensure system is operating properly.

DTC will not set if MSM DTC B1982, B1983 or U1300 is current. MSM DTC U1255 will set when MSM requests a message for initialization and the following criteria is met: Request is not acknowledged after all message retries are sent out, requested information contains an internal failsoft value, and the source ID with desired information is not known. MSM DTC U1255 will clear when conditions for setting DTC no longer exists or upon every power mode initialization.