Speedometer 20mph to HIGH ?

[89Cutlass]

Ive had my car for almost 2 years and the speedometer is about 20mph to fast like it will say 70mph and im only doing about 50mph. Im wondering what could be causing this what do i need to do to fix this anyone no ??

[NORBI]

did you have your transmission changed before?? This might be a little plastic thing in a transmission that may send a wrong speed reading to dash, i had a sam problem with my and then my mechanic showed me that part it a little plastic and has a threat on it and its about 2 in long so thats what it might be.

[89Cutlass]

Not sure if the tranny has been changed. I dont think it has at least to my knowlegde. but you could be right about the sensor. its a vss(vehical Speed senosr) it plugs into the transmission.

[no1kicker]

Do you have a DIC or HUD? If so, see if they read the same as your dash. If so, prob the VSS. If not, prob the calibration resistor on the back of the speedo. A new dash would fix or solder a new resistor on the speedo chip. I have a pic somewhere from Shawn let me know if you want me to post it.

[89Cutlass]

if you can find the pic that would be great.

 

thanks

 

Craig

[no1kicker]

Here ya go:

 

[88regal]

Not wanting to let you overlook the most simple solution; before you start trying to fix the problem, try seeing if you accidentally pressed the button that converts Miles per hour readouts to Kilometers per hour.

 

Hope that is all it is.

[Guest]

this also might not seem that obvious, but have put a custom or differant MEMCAL chip in your ECM. When I changed mine, it threw off the speed as well. All I had to do to fix that was put a differant gear in the VSS.

 

Taylor

[89Cutlass]

Well I no that the computer was changed in the car before i bought it so that says somthing but how would i go about this..??