Home › Volvo › 2011 › XC90 Base, AWD › Repair and Diagnosis › Engine Performance › System › Engine Control Module (ECM) Diagnostic Trouble Codes - 13 Of 13 › ECM-U012086: Lost Communication With Starter/ Generator Control Module. Bus Signal / Message Failures. Signal Invalid (B8444S; 2005-2011) › Fault-Tracing Information