9-3 Cabriolet 1999. No power to ECM

Hi , having problem with a 9-3 SE turbo 1999 year , B204E engine T7 system . There seems to be no power to the engine ecu . No communications with ecu , no engine light when ignition turned on . Checked all fuses ok , even tried a used ECM , same problem . Tech2 can communicate with all other systems , but not ECM . Any ideas much appreciated , thanks