Excuse me if I'm wrong because I don't know everything. So I'm gonna take a stab at this with what I do know. ( you didn't specify what model) On a 2001 Dodge 2500 5.9L 24 valve Turbo diesel; if the speed sensor goes out, your speedometer will not work, the cruise control will not work, and the ABS and brake lights will remain "on". Some times if it is erratice or bad, the speedometer needle will bounce around. Sometimes the above symptoms will all occur simultaneously and sometimes randomly but rest assured they will all occur pretty quickly. The rear speed sensor on this vehicle is located on the upper front center of the differential and is relatively easy and inexpensive to replace. I won't go into further detail but you can read all about it if you visit your local auto parts store and purchase an after market shop manual for your particular automobile. It will make a splendid, wonderful and special addition to your technical library.
there is one on the transmission and one located on the rear end. Get the error code and it should tell you which one is bad.
yes
The output speed sensor tell the computer what speed the trans output is turning to know when to shift.
tell me how to do it
Under the rear left brake pad
The rear oxygen sensor looks at the percentage of oxygen in the exhaust after it has passed through the catalytic convertor. The computer compares this with the reading from the front sensor to tell if the catalytic converter is working correctly.
can you tell me where the my 03 plate Mazda 323 2 litre diesels speed sensor is located as its not working .ta
It tell's it when to shift ....depending on throttle position
You can get a computer deal that will read your codes from your car and will tell you everything thats going on with it..i got one but it was around $200
There will be a two wire sensor sticking out of the top of the "pumpkin" if it has ABS.
Look for speed sensor wiring at the front wheel bearings. If you have front speed sensors, you have abs.
I can't tell you what it does, but I can tell you it is a pretty easy fix. I believe the part is in the 10-20 dollar range. The sensor is located on the driver's side rear portion of the transmission. Take it out with a 1 inch wrench (some fluid will run out of the hole. I replaced the sensor the first time the check engine light came on, however the sensor is magnetic and collects any ferrous debris in the transmission fluid, and simply cleaning it with a rag worked on subsequent occasions.