U1255, Generic Loss Of Class 2 Devices: Testing

WARNING: This page is about a different car, the 1997 Cadillac Catera. However, it is still accessible from the selected car via links, so may be relevant.

Clear DTCs and cycle ignition. Check for DTCs. If DTC U1255 exists, use scan tool to establish communications with each module on Class 2 data bus. Repair or replace as necessary. Ensure Class 2 serial data line is not shorted to ground or battery (DTC U1300 or DTC U1301 would be set). If circuit and individual modules are okay, replace BCM.