2001 Mercedes Benz 240d • 6 cylinder • 86,000 miles

Hi, I have a 2001 Mercedes Benz c2400 auto, sometimes if I select drive it, ll accellerate but sometimes its like stuck in first gear and when I ease off the accellerator it still wont change up, now this doesnt happen all the time, when it happens I have to stop select neautral then select drive again then it appears to be ok, ive driven autos for years, but this is all new to me, thank you
March 17, 2011.

Have the transmission control module scanned for code/s-could be a sticking shift solenoid/s, and the modulating pressure regulating solenoid valve, etc-When was the last time you had the transmission serviced-

Mar 17, 2011.