'98 CLK320 Replaced diff & trans fluid & filter, rear brakes, cleaned most connectors: Now MIL, limp home mode, only code = P0730 (improper gear ratio).
Code will clear with ODB II, but remains in limp home. Star Diagnostics will clear code and return normal shifting, but only for 10-15 miles. ODB will clear code, but trans remains in limp home - I can't clear the DTC's with my scanner. I pulled the valve body, cleaned it and checked all springs/valves/solenoids (to the extent I can with voltage pinouts and ease of movement checks). I did not replace the conductor plate, because all known (to me) voltage & resistance tests showed functional. Range recognition sensor also shows proper voltage values. TCU is dry, as is harness. I am not tech, or even a mechanic, just a guy who does the research and likes to spend a weekend under the car.
*Notable is that with ODB, the P0730 will clear and MIL goes out (limp home sticks though), but upon startup - with no gear selector or pedal actuation - the P0730 will immediately show up as "pending" with ODB. I am stubborn, and have spent so much time on this that I have to finish it myself. I read a reference that in an extreme circumstance, MAF or other flow issues could create this error. This seems unlikely to me, but I haven't spent a month on this because I'm smart. Does anyone know if an intake problem or something south of the torque converter could cause a gear ratio code. It seems relavant to me that the code immediately appears as pending, before any gear is engaged. Remember, I changed rear brake pads, diff. fluid, trans fluid & filter, just before this happened, so I could have screwed any number of things up. HELP!!!