My 307, has this issue with the transmission/gearbox. The vehicle will run normally if i am accelerating or keeping the car in constant speed. If I decelerate, the transmission changes down (and this is normal). After this the transmission cannot change up anymore. If I restart the car then the transmission changes up normally until the fourth gear, but if I decelerate, then the problem persists again, so the transmission changes down and never will changes up until I restart the car. Any ideas on this would be greatly appreciated as i have been hassling with the car for more than 3 months and the local delaers can't give a clue about this.
Martin