Question6-18-08 Hi Roland, I did the test that you sent me. After unplugging the TCM and performing the test again, the 66 Code went away. So as you suggested, I replaced the TCM. When putting in the new TCM, upon driving the car for the first time, it was in limp-in mode, so I stopped it, turned it off, turned it back on, and the transmission was working fine. I drove the car for the quick-learn procedure (I’m sure you are quite familiar with this) for the first 20 miles or more, car ran perfectly, shifted perfectly, everything was fine, and then it started shifting HARD through its gears, banging into each gear. Then last night, coming off the highway to my exit, as I decelerated down to the yield sign for a right hand turn, it slowed to about 5 miles per hour, I returned my foot to the gas pedal, and upon acceleration, the car banged violently into first gear, even chirping the tires, Could I have possibly have bought a bad TCM ( it was new). OR do you think, or possibly know if another, maybe the VSS or possibly the shift selenoid, or other …. May be causing the problem.? Let me know what you think, because the problem seems worse now than before.
Thanks, Mike
AnswerHi Mike,
Sorry to hear about this.
The more benign possibilities for harsh downshifting are:
engine idle speed too high, aerated fluid, low fluid level, hydraulic pressure too high, valve body malfunction or leakage. The balance of the causes involve internal mechanical issues. How about another fault code readout? The underdash data link connector would have to be the port and a reader equivalent to the Chrysler DRB II would be required to read the transcontroller memory.
Roland
