how can i fix my vectra ?

No.
The light is telling you there is a problem and that fault codes have been stored. You have to read the fault codes and fix the faults, then the light will go out.
On some model years you can read the codes manually, later cars need a diagnostic reader such as tech-2, vaux-com, op-com etc..
Basic code read from an independent is about £30/£40, full diagnostic from a vauxhall dealer about £80/£100.

gbb777
May 2009