After going through the many threads regarding transmission issues, I have yet to pinpoint exactly what my problem is. I have a 99 ML320, that is out of warranty. A very good friend of mine is a ASE master technician and he is helping me repair the vehicle. He has the scantools to extract tranny codes, so I have those codes available to anyone who could help me out.

Anyhow, a couple months ago, every couple of days the car would either not shift up into a higher gear, stuck in 2nd gear it seems, or get stuckin 3-4th gear, and will not downshift when vehicle has slowed down to a stop. This means at a stop light it would accelerate extremely slow due to the higher gear. I would then turn the car off and turn it back on, and the problem would be gone. Back to normal.

A couple of days ago, the problem has came back, but this time, it is here for good. I tried turning off and back on to no avail. So right now, it wont upshift past 2nd gear. I initially presumed it was limp mode related, but my friend says a code related to the RPM sensor is being indicated in the computer. I dont remember the exact code number off hand, but I can get it again.

Anybody have any ideas? I'm guessing that the RPM sensor is faulty or something with the conductor plate and the RPM sensor. Is changing the RPM sensor something easy to do, and how much does it run cost wise?

Thanks,
xbrxx