Nissan Repair: speed sensor on 95 nissan pickup, vehicle speed sensor, speedometer cable

Question
the check engine lite comes on for a while, goes off for a while. a shop told me the repair code was the speed sensor and my speedometer, etc should not be working. But it works fine.  I have run the truck like this for over a year now - still have the lite on and off but speedometer, etc. work fine.  Had it checked again - same code. Does this need to be fixed if the speedometer, odometer, etc are working ok? Hate to spend $300 to fix something that doesnt' matter.  Thanks

Answer
Gary,

The vehicle speed sensor is a pretty easy change since it just plugs into the transmission where the speedometer cable used to.  Just unscrew the bolt that holds the retainer and pull the sensor out and replace it.  It is nothing more than a square wave generator that sends the vehicle speed to the speedometer head.  This is where the computer gets the speed information.  The computer ties into the signal at the speedometer head.  If you check rockauto.com you should ge able to get one for around $50 bucks.  It only takes a ten millimeter socket to remove the bolt.  I would change it to eliminate the problem.  The truck will not run properly when the code is on as the computer goes into limp mode and your mileage will suffer as a result.  If the light stays off more than on you could probably get away with waiting but I would just get it changed.