Chrysler Repair: fluctuating speedometer, 4 digit numbers, question pool

Question
My 2002 Jeep Liberty has a malfunctioning speedometer (doesnt hold speed-fluctuates). I have noticed that the upon accelaration I hear a small notice coming from the transmission area (not all the time). Is this indicative of a worn outspeed sensor? If it is what can I expect to pay for repairs?

Answer
Hi Luis,
The output speed sensor is what produces the signal to the speedometer head so it is a prime suspect if the speedo is unstable. It also is an input to the transmission controller and it may cause some inappropriate shifting to occur when that signal is irratic.
The sensor is in the range of $75 and is a simple replacement: unplug electrical connection after lifting locking tab gently, unscrew old sensor, screw in new sensor, tighten to about 20 ft-lbs (the same as a spark plug). It is located on the left side of the trans, near the end of it.
Roland
PS If you live near an Autozone parts store you can get a free readout of the memories of the computers via a socket under the dash.
That might be a way to corroborate that the sensor is bad, or it may tell you something else. The codes are 4-digit numbers, ask what a code means, what to do, how much; then write back and we can compare notes.
(This is a duplicate answer given because your question was duplicated in the 'question pool')