The limiter has kicked in because the engine management light is on.
The engine management light is on because the system has detected a faulty or out of range signal from one of the many sensors and actuators fitted to the car.
The only practical way to find out which component has logged a fault is to plug the car in to a diagnostic code reader.
Some vectra models can be checked using DIY methods, but you haven't bothered to give enough detail about year, engine, fuel type.
spud, September 2009
