Hey, I'm new to the site so sorry if i post this in the wrong spot, i have a 1999 dodge ram 2500 5.9 v8 and it seems to have a vss sensor problem. The check engine light is on and the abs light is as well. Also my speedometer stays on 0 and my odometer stays on the same mileage, also my cruise control doesn't turn on aaaaand my trans seems to be shifting weird. I went to autozone and they read the CEL code and it come up saying the vss sensor is bad, the problem is i changed the vss and abs sensors and it didn't help. I also tested the speedometer to see if it would move when i reset it and it does work, however i get the codes 999 and 950 on the odometer screen. Do you guys think its the wiring maybe? Thats the only thing i can think of since i already changed what the check engine light was on for.

Any input is appreciated, THANKS!

 

Also, is it easy to check the wiring for the sensors?

 

All of your problems are related to no signal from VSS. I think the first thing I would try is replacing your replacement part. Wouldn't be the first time someone got a bad part, right out of the box. (and it should be a warranty replacement...... so, doesn't cost anything.) Make sure that it is mounted properly, and seated all the way in.

Clean the connector really well too.

If that doesn't help, gonna have to follow the harness from the sensor, up to the PCM, look for breaks in the wire, or if it got crushed somewhere.

 

I replaced the vss again and still have the same problems.

So you think i should check the clip thing that attaches to the sensor and clean it?

 

Can't hurt. May also want to pull the cover on the rear diff, and see if the tone ring is still in place.... (I really don't see that being the problem though....)

With the engine running, you should get like 5 volts on one of the wires. (wiring diagram will tell ya which one....)

 

I was getting the P0720 engine code, for speed sensor. It turned out to be the speed sensor in the transmission, driver side. A Simple fix, 1" box wrench gets it out.