DTC U1255: Generic Loss Of Class 2 Devices: Notes

During normal vehicle operation, modules on class 2 serial data line monitor data line to exchange operating information and commands. Modules on serial data line send a State Of Health (SOH) message about every 2 seconds to verify system is operating properly.

DTC U1255 will set when system voltage is in normal operating range (9-16 volts) and BCM and radio receiver detect no messages on class 2 serial data line. A current DTC U1255 will clear when a valid class 2 message is detected or at end of current ignition cycle. A history DTC U1255 will clear when scan tool is used.