What's a VSS?

[Outpost]

What exactly is a Vehicle Speed Sensor? Where is it located and how difficult is it to replace? Who can supply one of these and about how much should it cost?

Thanks in advance!

 

[Roc87]

A speed sensor tells the ecm how fast the car is going, so the ecm can send a signal to lock up the converter. It is located up behind the speedometer.....

 

[Outpost]

Is it attached to the speedometer? We just installed a Kirban 145-mph unit...Did we just change the VSS? If not, who sells these things and how much do they cost?

 

[Roc87]

Did it include the "reducer"? I'm guessing it did because my friend just bought one of these kits. His Scanmaster was reading different than what the speedo showed. He took the speedo to a speedo shop and they had to "demagnetize" it. Works great now...... It's a little (Green, I think) box that is attached to the speedo on the back, near where the cable goes into it.

 

[Outpost]

I don't think a a reducer was part of the unit. When I swapped speedos I simply unplugged the speedo cable from the original unit and plugged the cable into the new speedo. It reads within one or two mph of the scanmaster.
How can I be certain if I swapped the VSS? I don't recall that the back of the new speedo appeared any different than the unit I took out of the car.

 

[Roc87]

Oh, you swapped out the entire speedometer? Well, if the scanmaster is reading what the speedometer says, they recalibrated it (Doing it the right way) so the odometer and trip are still acurate.

Some vendors sell just the speedometer overlay, and use a 5/8 reducer to make the speedo accurate, but by doing this it causes the trip and odometer to read false, and also the VSS. Sounds like you got the right one though........