Nissan Repair: 2002 nissan xterra speed sensor, nissan xterra, speed sensors

Question
QUESTION: Hey Calvin,
Well my speedometer stopped working and the service engine soon light came on, on my 2002 nissan xterra. I hooked up the computer scanner to it and got that the speed sensor needs replacing. The problem I run into is I see there is multiple speed sensors for my vehicle. A total of three. One for the rear and one each for the front wheels. The speed sensors are also called ABS speed sensors or anti skid sensor. Which one controls the speedo? my guess is the rear would, but I want to make sure before I drop close to 200 dollars.
Thank you for your time.

ANSWER: Hi Ben -

Can you tell me the exact code number that was displayed?

LMK
Aloha
Calvin

---------- FOLLOW-UP ----------

QUESTION: Code: P0500
Definition
aaVehicle speed sensor circuit fault
probable cause
aa1-open or short circuit condition
aa2-poor electrical connection
aa3- speed sensor fault
aa4-processor error

Answer
Hi Ben -

My first check would be the speedometer gears.

I think it is the center one that goes into the trans and spins with the gears. To check - Remove it and plug the wires in Spin the gear on the sensor and see if the speedo moves. If it does, then you have found the right one. You may want to inspect the harness for places it may have rubbed against the frame and may be causing an intermittent short. Inspect the gear for damage also. If the gear is damaged that would mean the drive gear for the speed sensor in the transmission is damaged also.

My feeling is that if the speedometer is not working, you have a faulty gear, and since the sensor is not picking up the movement of the gear, it throws the light on. I would check the mechanical stuff before condemning the part.

Hope this heslp -
aloha
Calvin