after turbo change and battery disconnected for a moth ,
car has no idle. on 2002 Volvo S40

replaced idle control valve ,coolant tem p sensor no help .no codes
at OBS show Mod 1 and Mod 30 not worwing could be ECM bad.removed
idle control valve with sw on valve does not move to open voltaje
dc aprox .90 volts.or need re programing ECM

1 answer
drive car for approx 5 mins and see if it relearn proper idle