My speedomter will sometimes not work, and then a CEL came on, I took my car to autozone, and they diagnosed it as a speed sensor failure. I am thinking it has something to do with my Yellow Jacket, but I checked and all my wires appear connected, and the yellow jacket itself (modifry version) has the self diagnosis light showing that it is connected and functioning. Anyone have any idea what else it could be?

 

bump

 

Probably your actual vehicle speed sensor then I would guess. It's located on the side of the transmission.

 

Check the ground wire on the back of the cylinder head. It is directly related to speedometer issues.

 

Is there an easy way to access the ground on the back of the head? I tried the other day just to see if I could look behind the head but there was no room from the top. I am guessing there is more access from underneath?

 

top access only. get a mirror to locate it.

 

Ok I will, once I locate it, if it looks loose, what would be the best tool to tighten it? Just a regular wrench? I hope this is the case. Thanks for your help.

 

Does your Milage still work?

 

When the speedometer doesnt, then the odometer doesnt as well.