The Last time I tried KTS on a Y17DT Astra's or Corsa's it wouldn't work at all. ( Not updated it in last 12 months ) I alway's Use tech 2 on those models, And I remember recently using the Jk100 as the tech 2 was in use on another job, It came up with a wrong fault code completely, Luckily I re-checked it with the Tech 2 when it became available as i couldn't believe the fault code that it had thrown up and saved wasting lots of time going round in circles checking something that wasn't wrong in the first place.