# Vehicle Speed Sensor Malfunction (P0500)



## Foundsoul (Jun 15, 2005)

I have a 97 Pathfinder SE (4WD) that recently had the "Service Engine Soon" light come on. I went to AutoZone and checked with an OBD scanner and got the P0500 code (Vehicle Speed Sensor malfunction). Based on previous threads (and the Haynes manual) if the speedometer works it is highly unlikely that the VSS is defective, but the code might come up if the wiring (either to the speedometer or the PCM) is bad. I also know that the VSS is located on top of the transmission. The Haynes manual shows a picture of the VSS on the transmission, but it is such a close up picture I have no idea where it would be located in the engine compartment. To replace this or check the wiring is this something where the tranny has to be dropped down in order to access the parts? Or is there an access panel under carpeting from inside the car, and is that going to allow me to access the wiring in case I need to replace it? Any help would be appreciated (pictures far enough out so I can see what to do would be even more appreciated).


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## Foundsoul (Jun 15, 2005)

*Problem solved*

Follow-up to post: I finally had to take the car into the shop (I hated doing it because I'm a DIYer), but time got the better of me and I was on my second trip permit. Anyways, the problem turned out to be a bad instrument panel (speedometer) AND computer (ECU). The vehicle speed sensor was replaced as well, but the circuit board for the speedometer had discoloration in one corner and that was the location for the connection to the ECU. The speedometer was sending a 0mph signal to the computer and as well has shorted out the part of the computer related to "communicating" with the instrument panel. I could still get a correct speed (speedometer working) because the connection from the VSS to the speedometer was fine. They tried the old computer with the new instrument panel and no luck so they replaced both and the engine light went away and I passed DEQ. FYI, the cost was about $800 in parts (VSS=$200, instrument panel=$260, ECU=$340) and about $400 in labor.


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## djhaase (Mar 12, 2009)

I may have a similar problem in a 1997 pathfinder. My speedometer would intermittenlty not work/ get stuck in one position. Then I received an error code P0500. My speedo seems to work fine now, but I still have the SES light on. 

The ECU, is that the same as an ECM? It appears like it would be mounted under the passenger's seat? Any idea how hard it is to get the speedometer off?


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## swabjockey (Apr 12, 2014)

tighten screws on back of speedO. worked for me on 1997 nissan pickup.


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## smj999smj (Jan 1, 2006)

The issue with mid-90's Nissan speedo heads is that the threads develop cracks in them where the mounting screws go, to attach the speedo head to the back of the instrument cluster and printed circuit. Tightening the screws will often "fix" the problem temporarily, but the best way to fix it is to replace the speedometer head assy. It's not common for the ECM to be damaged because of this.


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## gregoryrt (May 28, 2014)

I have a 99 pathfinder and the other day my cruise control cut out and speedo quit. The yellow light on dash says OD off. I put my code reader to work and it says engine speed sensor po500 code. I went under pathfinder and located sensor on transmission. I took out screw from sensor and tried to remove with hand, but it didn't move. I wasn't sure how to remove so I took vehicle to Applewood Nissan in Surrey to have them replace it. The next day Applewood phoned me and said they couldn't remove it, they heated it and broke off screw flang and said there's nothing they can do. Has any one else had any problems removing this sensor? Are there any trade secrets to getting this out. I find it hard to believe that their is no fix other then replacing transmission if I want speedo to work. Any help would be appreciated.


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## smj999smj (Jan 1, 2006)

Soak with rust penetrent overnight, heat with a torch, large vice grips and elbow grease. A chisel and hammer sometimes comes in handy!


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## gregoryrt (May 28, 2014)

Thanks for your information. I will give it a try as soon as I get a chance. Greg


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## smj999smj (Jan 1, 2006)

I used to see a lot more speedometer heads causing the P0500 than faulty speed sensors, FYI. Rather than potentially destroy the VSS, you should measure the output with an AC voltmeter. Typically you'll see about a 1 volt increase for every 10 mph. If you get a reading from the VSS, I would try tightening the bolts at the back of the cluster for the speedo head and see what happens.


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## gregoryrt (May 28, 2014)

Thanks but I don't have that option anymore. I took it to Applewood Nissan in Surrey for Testing. The broke the flange off the speed senor and damaged it pretty bad only to tell me they can"t figure out how to remove it. I will now have to figure out how to get old one replaced before I can even replace speedo head to test. Thanks Greg


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## gregoryrt (May 28, 2014)

gregoryrt said:


> Thanks but I don't have that option anymore. I took it to Applewood Nissan in Surrey for Testing. They broke the flange off the speed senor and damaged it pretty bad only to tell me they can"t figure out how to remove it. I will now have to figure out how to get old one replaced before I can even replace speedo head to test. Thanks Greg


updatehoned Nissen Canada about my speed sensor problem and what to do about the fact that authorised Nissan Dealership made problem worse by breaking senor flange right off. Nissan Canada said they would check into it and try to resolve the issue. They phoned me back several days later and said so sad to bad not our problem, it's not on warrenty. I'm am saddened by a big company like Nissan doesn't hold their authorised service dealers accountable. It will be the last time I take my Nissan to factory service dealership. I could have got better service from a back yard sledge hammer mechanic. Thank you Nissan Canada.


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