I have a 1998 C250 and it developed a problem where the gearing seamed to slip at times, then it wouldnt change up, then after a while it would come out of gear altogether untill the speed dropped to 20mph then the gear would kick in.
I took it for diagnostic, changed the oil and they said it was not electrics there must be a problem with the gearbox. I changed the gearbox and still had the same problem so took it back to Mercedes who thenre-did the diagnostic and said again that it was not electric so I explained about the change of gearbox so they stripped the original box and then got back to me saying "they have narrowed it down to the ASU" it may be the problem but they cant simply put one on from another motor even to test it, it must be ordered specifically for my car and it is pre programmedfor the specific car.
Is this true, I'm not willing to pay for this 'try' as it is £600 or $1000if this is not the problem. Why has it not come up on the diagnostic? HELP!