Vehicle Speed Sensor

[wolfehunter]

Speedometer quit on my 98 Chevy Truck almost two years ago. Posted on here about it and with help was able to locate the VSS, remove it, clean it up, reinstall and has been working since. Until last Saturday morning on the way to work it quit again. Did the same routine but this time it did not correct itself. Drove it a few times since and was going to order a new VSS from Rockauto until it started working again last night when I drove it!!

My question is do VSS's intermittently stop working when they are going bad or is it a part that will just quit? Just trying to determine if it is the VSS or if I have a problem with the electrical plug/wiring instead.

 

[GenesisGuy70]

Are you sure you've not got a pinched wire or anything? Did you use dielectric grease on the connections?

 

[Lubener]

They act up intermittent or all the time.. Most are a reed switch. I would clean the female mating connector first. I have been dealing with an intermittent speed sensor for some time.Dielectric grease will help keep moisture and corrosion from forming in the connector once you clean it up.

 

[zzyzzx]

I also think you have a bad piece of wire or bad electrical connection.

 

[wolfehunter]

I only cleaned up the TSS. The connections "looked" very clean so I didn't touch them. And I did not use dialectic grease. I will clean them up regardless of how they look and try the grease. Hope that solves it. Thanks.

 

[eljefino]

How's it read? If it's a magnet in the rear axle I could see it picking up metallic slivers.

 

[wolfehunter]

It is located on the back of the transmission and it is a magnet. I cleaned all the fine pieces of metal off of it when I removed it last week. It didn't work initially after putting it back in but did start working again a few days later.

 

[clinebarger]

Is this a Automatic truck? If so, A dead VSS will cause the trans to not shift out of first, And the ABS lamp will come on.

If your only symptom is a dead speedometer, Your looking in the wrong spot.

The VSS sensor is wired directly to the PCM, The PCM converts the AC Sine Wave signal the VSS produces to a DC Square Wave signal for the ABS & Speedo.

 

[wolfehunter]

Yes, it is an automatic. And yes, the speedo was the only symptom or problem. I disconnected the plug at the VSS last night, sprayed it with contact cleaner, left it air dry, applied dialectic grease and reconnected. So far so good. Hoping the issue was some moisture or corrosion at the connection causing the problem.