cocovation

My car's Service Engine Soon light had come on a few weeks ago, and the code my car computer spit out was P0720 (speed sensor). The problem was my car would intermittently not go over 30 miles per hour. Not knowing there was more than one part that went by that name speed sensor, I bought the following part and replaced it on my car: http://shop.advanceautoparts.com/p/c...3-P#fragment-1.

However, that didn't fix the problem. I found out later there was another part that is called a speed sensor, as well as a few other names: http://shop.advanceautoparts.com/p/d...m=speed+sensor. I replaced this one yesterday, and it's solved the problem of my car not going over 30 miles per hour.

My question is what is the difference between and the functions of these two sensors? I've searched online, but the problem is since both can go by different names and the pages I've looked at don't show pictures of the sensors they're defining, I'm not sure of what I'm reading.

Thank you so much!

maxiiiboy

The first sensor (VSS) provides input for the vehicle instrument cluster. The second sensor (called "Speed Sensor AT", aka "revolution sensor") provides input to the TCM.
If your speedometer is working then there is no point in replacing the VSS. Your problem was clearly caused by the Revolution Sensor as the car would not shift properly.

cocovation

My speedometer is not working at the moment.

When my Service Engine Soon light first came on was when the car started intermittently not going over 30 miles per hour. The code from the car computer said it was the speed sensor, so I installed a new one of the first part I linked to, not knowing there was more than one part called a speed sensor. I replaced that first one about three weeks ago, but it didn't fix the problem of the car not going over 30 miles per hour.

Last week, my speedometer stopped working. Friday, I replaced the second speed sensor I referenced in my original thread, the one also called the transmission revolution sensor. However, my speedometer still isn't working, and I noticed now that my odometer isn't working, either. (The other gauges seem to be working fine, though.) Replacing the transmission revolution sensor seems to have corrected the acceleration problem, even though with the broken speedometer I don't know how fast I'm going, because after I replaced the transmission revolution sensor, I no longer had the problem of the tachometer pegging too much to the right when I would try to accelerate.

Since in the last three weeks I've replaced both of the sensors I linked to in my original post, and my speedometer is still not working, what should I check next to fix that and the odometer?