'Control Sleeve' could be a mis interpretation of 'Throttle body'. Dunno if this will help...
P1226 Closed Throttle Position Learning Performance Problem.
iirc theres a fiat fault similar to this listed as "throttle learn procedure stop" which basically means the throttle body 'auto-learn' sequence was interrupted. For Alfas i would have thought there is someway of 'teaching' the throttle body without the need for diagnostic kit. I'm too new to Alfa so i dont know the procedure (and i own an oil burner, so i have no need to know) a more seasoned petrol owner may be able to help.
does she idle funny or have any strange acceleration behaviour? does she go into limp home mode with the MIL or does it just come on with no other perceivable symptoms?
'07 159 Lusso Saloon, 2.4 JTDm, Oltremare Blue.
'99 Fiat Coupe, 2.0 20v VIS, Portofino Blue, Full Leather, Mani-Back Longlife Custom S/S Exhaust.