I've been having this problem on my 2006 Vectra 2.8l Turbo for a while now.While driving, the TC icon on the dash lights up and after 5 seconds the Continous Damping Control (CDC) icon lights up too (its the icon shaped like a suspension damper and has an exclamation mark next to it). I turn the car off and then back on, the icons are still on, i drive for 20 meters, they go off. After a short while they come back on! It's driving me nuts! And to add some icing to the cake, the tire pressure monitor icon lights up in yellow as well when this happens but not all the times.I took the car to the dealer's, they said they couldn't see anything wrong with the car when they had it plugged to their diagnostic machine. I insited and had an argument with them. They took car in for a day. When i came to pick it up, they said it was a broken tire pressure sensor and they changed all 4 under warranty and the car should be ok now. I think I drove 50 meters from the dealership and boom! All the icons were on again! Drove back and showed them. Same story. Next day, they said it was the main unit for the presure monitor sensors causing this and they changed it. You guessed it, all the icons on the dash still light up. The dealer doesn't have a clue on what is wrong. Car is still under warranty. Any ideas please?