Hyundai Repair: Speedometer, odometer, trip, vehicle speed sensor, hyundai elantra

Question
Hyundai Elantra 2001 gls, automatic transmission, 2 l engine, problem: suddenly speedometer, odometer and trip stop working. Is signal for speedometer sending abs sensor on front wheels passenger side or signal for speed sending 2 speed sensors on transmission? 2 years ago I had problem with shifting and I changed one speed sensor on transmission and it works 2 years OK but that time I had not problem with speedometer, odometer only problem was from 4 gear drop on second gear and speed was 30mph. This time gear is ok , I can speed until 80 mph (shifting is OK)  but only speedometer and odometer and trip are dead.
Thanks Enes

Answer
The speedometer (and odometers) receive signal from none of the sensors you mention.  The sensor in question is called a vehicle speed sensor and is on top of the differential portion of the transmission.  It'll be all the way on the engine end of the transmission, all the way in the back, and down much lower than the input and output speed sensors.  I've commonly seen this sensor fail as well as wear of the plastic gear which turns it.  

It's typically my recommendation to replace both the gear and sensor at the same time if paying for labor because this is insurance you won't have to pay a second time for labor if inspection is inconclusive.  If you're doing this yourself, you might remove the assembly and inspect the gear.  Then, if it looks okay, replace the sensor first.  If you can see noticeable wear, replace the gear first.  Either way, if you don't see something very conclusive, know that you might have to disassemble it twice.

In addition, on your initial inspection, check the wires at the connector for the sensor.  Although rare, I've seen them break in this location.