I got this car from a friend I traded him a 1991 rhd 300e he said the dealer in the past month jan 2014 did 2700.00 worth of transmission work . It worked well for a few months then started acting up. I drove it about 25 miles and it worked perfectly then I came into town ,stopped at a light the engine revved up but the car went nowhere turned the car off and pulled the key restarted and it worked fine for another 5 minutes . I repeated this operation until I made it home. I tried it again the next morning and the same thing. I did some research pulled a code of p0715 rpm sensor and decided to replace the connector plate on top of the transmission valve body and the plug. Before I started I checked the TCM for signs of oil or other issues and there were none.I did the job claned everything very well put inn the new parts and the new fluid cleared the code and when I drove it it would not come out of 2nd gear and 4 minutes later the check engine light came back on . I am just wondering where to go to next or if I have made an error , any help would be appreciated the car has 180000 kms thanks