Chrysler 300M Transmission?



My 1999 Chrysler 300M has 183k miles and has been running well. Yesterday, just after pulling out of the driveway, it shifted very hard. After that, it would not get out of second gear. I cannot even change gears manually. What’s up? Am i going to need a new transmission? If so, how much does it cost and is it worth it.


One more thing. The “check engine” light came on and has stayed on. Please help. This is my only car.


Many Trannies these days are computer controlled. Although I don’t think any are hooked up to the OBD system. Anyways the first thing I’d do is have the code read…May be related.


You most likely do not have a mechanical transmission problem.

The automatic transmission uses some of the same sensors used by the engine computer. If one of the critical sensors, Throttle Position Sensor (TPS), Manifold Absolute Pressure (MAP), Mass Air Flow (MAF),
Vehicle Speed Sensor(VSS) fails or the wiring becomes compromised the engine computer will turn on the ‘Check Engine’ light and the transmission computer will switch to the ‘limp home’ mode which is full line pressure (harsh shifting) and second and reverse gears only. On your car the engine computer and the transmission computer may be one unit so the ‘Check Engine’ light may serve both. Usually the tranmission computer flashes the OverDrive (OD) light if it detects a problem.

To diagnosis the problem have the computer(s) scanned for codes. That will point you in the right direction.

Hope that helps. Get back to us on what you find.