Fatigued or broken wires to the output speed sensor can cause problems with the cruise control, erratic shifting, and speedometer operation. This may also cause Check Engine Light illumination.Google+
Car Problem Reports
Chrysler Concorde Worn Wires to Output Speed Sensor May Cause Problems With Cruise Control/Shifting/Speedometer
Chrysler Concorde Problem
Visitor, 1998 Chrysler Concorde, 96,324 mi
my concorde lxi 3.2 litre tries to stall at lights,speedometer quit working,and it doesnt shift right anymore.I just bought a new output speed sensor for 16.98 will put it on tomorrow and check the wires,it should fix the problem.