One problem related to speed control cable has been reported for the 1999 Chrysler 300M. The most recently reported issues are listed below.
From idle, throttle jammed wide open when accelerator was depressed. Throttle cable remained stuck open after engine was turned off. Incident may be similar to other reported incidents for Chrysler lhs (odi id's: 701997, 832642). Lhs shares drive train with 300m and may have similar throttle.