Where is the speed sensor in 94 Prizm?

I have a 94 Geo Prizm, 103k mileage. My speedometer stopped working a few months ago, it kicks in when I'm driving fast on the interstate. Today I was driving on the interstate and the speedo kicked in, then the check engine light came on and then off, the speedo went back to 0. After reading some messages, I think it might be the vehicle speed sensor.

Can anyone tell me where this is located on my car? Do I need to get this fixed? It doesn't bother me that my speedo doesn't work. What's the cheapest way to fix it? Thanks in advance for any replies.

The part is on the top of the transmission and is easily reached. The part is very expensive from the dealer, try a junkyard. Replace the part when the car is cool. Get a cheap manual.

Thank you so much for your reply. Yes, I found out it's an expensive part - $265 and that's just from a parts store. I'm looking for salvage yards.

Do you know if this needs to get fixed ASAP? Will I damage my transmission?

You will not ruin the transmission. I bought one from the junk yard for 15$.

Would the odometer & trip odometer continue to function if the speed sensor is defective? I just hit 144k & the speedometer only kicks in at hiway speeds & is not accurate, but the odometer is fine...
Thanks!
Charlotte