ECM-740C Communication, central electronic module (CEM). Signal too high
ECM-21CC Long-term fuel trim, idling, bank 1. Upper limit
ECM-21EB Long-term fuel trim, bank 1. Signal missing
CEM-3A00 ECM software. Faulty signal
740c and 3a00 mean you have a "tune". They never go away. Other two may be a problem if they reappear .
Repaired by Volvo of Edison yesterday and the cost was zero dollars and zero cents because of they are extending the warranty for the airbox and attached hose going from airbox to the head. They also updated the computers and cleaned her up with a wash & vac. Finally got a chance to enjoy her on the ride home this morning! Of course I tuned her before my drive Thanks for your help SSers.