My speedometer just stopped working is it something that I can fix at home or should I take it in?

Question edited for clarity.
Question moved to model category.

You connect a code scan tool and it tells you the issue. It will likely say a P0*** code that is 'VSS Failed no signal'. VSS = Vehicle Speed Sensor.

https://www.google.com/search?q=2002+chrysler+300m+speedometer+not+working

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The speed sensors will not fix it. This is something that these cars will do in hot weather. The instrument cluster need to be removed and the contacts from the printed circuit to the connector need to be cleaned. Over time they will lose contact and affect the fuel gauge or speedometer. You may have to replace the speedo cluster. Sometimes if you hit the dash just above the fuel gauge it will start working too. Been there done that, fixed mine as the printed circuit was coming apart at the harness connector.

Sounds like the speedometer/odometer cluster or the dash cluster itself has given up. Suggest checking Ebay or googling "digital dash rebuilders" for some rebuilt units, or you may be able to get a factory unit from the dealer. This happens a lot. A resistor in the printed circuit can go bad or the units themselves can go bad. An entire rebuilt or good junkyard unit is the preferred fix.Sounds like the speedometer/odometer cluster or the dash cluster itself has given up.

this vehicle has an electronic speed sensor located on the trans i do believe but im pretty sure this is your problem change it and your cured

My 2004 chevy malibu speedometer stop working after battery died

Your speed sensor has failed. The vehicles speedometer is not cable controled, it's controled by a sensor in your transmission. It's a easy fix, but the new sensor is about $80 to $100 depending on where you get it.

sit in the drivers seat close the door. with the key off hold the trip odometer button in then while holding the button in turn the key on. if done correctly this will put the MIC (mechanical instrument cluster) into a self test. if the speedometer does not move like the rest of the gauges during this test the MIC must be replaced. if the speedometer does move it is likely your problem will be fixed, however, if the speedometer does move but it does not start working properly then further diagnostic will be needed.

There are 2 sensors on the engine that sent a signal to the computor and speedometer and tach. When one of these goes bad it can make the speedometer and tach go all over the place and also just stop working. This can also cause all types of engine running problems because the information being sent to the PCM will be incorrect all so. The units are easy to replace once you find them, it seems that they are located in different areas of the engine with each year the vehicle was put out.

maybe speed sensor switch? usually located and attached to speedometer cable at transmission!??

replace the ip cluster will fix speedometer