fault management light?

i have a vauxhall zafira 2.0 diesel. when i start the car, the battery light and the fault management light stays on, and the rev counter does not move. i have to sit revving for approx 5 mins, with smoke puthering from the back, until suddenly the rev counter goes up and the lights go off . i can then go on my way. this seems to indicate that its something to do with the engine being cold. please has anyone got any ideas what this could be, as im loath to take it to a garage a) because im skint, and b) because it might be something simple that my husband could fix. thanks