i have a mercedes a180 with automatic transmision problem. when i start the car and i start driving, the gearbox wont come out of 1st gear until we reach 20km/h. when i reach 20km/h it goes in 2nd gear. but the car is going very slow til 20km/h. i can press the pedal to max but car is takeing speed veeeeery slow... rpm's can go til end but car is going very slow... when i get 20km/h. it goes in 2nd gear and it runs normaly and in3 and 4 works perfectly... shifting up and down its great. but when i stop and try to start from 0km/h agin the same problem... What seems to be the problem?