My problem is VAG-COM can't contact ECU of my A3 1.8 (1996). Connection to ABS, airbags, central lock and meter panel (probably that, it was some time ago I last tried this) modules seemed to work. I changed connection parameters, pretty randomly though, but that didn't help. No any kind of signs of life from ECU.
Any ideas how should I start debugging this? I've got Haynes' manual but wiring diagrams in it don't seem especially complete concerning ECU.
Car is in running condition. It has only slight problems with starting occasionally, so in theory I could take it to Audi service. However, as I'm anyway pouring most of my money into this car (I'm a student ), it would be excellent if this could be repaired at home garage.