One problem related to automatic transmission control module has been reported for the 1999 Chrysler 300M. The most recently reported issues are listed below.
1999 Chrysler 300m, driving along freeway at 60 mph, sudden deceleration. Big scare for wife coming home in rush hour. Speedometer read zero, and the transmission was stuck in first gear. Could not get car to shift into another forward gear, still would go into reverse. Had to call tow truck to tow through houston, 65 miles to home on west side. $165. 00 for tow alone. This issue, I see, is common with this car. Why doesn't Chrysler address this problem??? tcm transmission control module, or transmission solenoid pack may be to blame, I think it's the transaxle output speed sensor, since speedo is not working. Transmission had no prior sign of problems. Love those computers. Sure do hate them in my car.