# P0500 error code won't go away!



## Jdoggsc (Dec 25, 2007)

I have a 1997 Sentra GXE, manual, with 1.6L engine.

I've read a lot of similar posts, but nothing really the same as what i'm experiencing. each time the MIL comes on i get just the P0500 code. the speedometer works fine. The posts i've already read about this indicate that there's wire running from the speedometer to the ECU that may be shorted, so even though the sensor is functioning properly, the ECU just isn't getting the signal. When it first came on, i replaced it without checking the forums; partly for the fun, and partly just for the security of knowing the part was new. Because of my work schedule i haven't had the time to pull back the center console and dig around the ECU and check voltages and stuff. I've pulled out the instrument cluster 2x now and pushed all the wires in to make sure they're cinched in. Driving around the city, the light consistently comes up, although I regularly clear it with my OBD-II reader.

SO GET THIS: Three times now, i've cleared it mid-drive on the interstate by engaging the clutch, switching the engine off, clearing it, and compression starting it back up again. I've done that 3x while driving 6+ hours on the interstate and the whole time i'm driving it won't show any codes, but a few days later, while i do mostly city driving, it'll come back on persistently again.

Does the ECU not read a signal from the VSS at highway speeds? That's the only way it makes sense to me. why would it not come back?

short of hunting down some obscure wire behind the dash to make sure the signal is getting to the ECU, what should i do to fix this?? I would rather not replace the instrument cluster either. any ideas?!?


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## metro273 (Sep 16, 2005)

You need to change the speedo head. It has a circuit board behind it that goes bad and you can't just look at it and determine where the problem is...unfortunately!

Btw, I assume you are getting the VSS code?


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## Jdoggsc (Dec 25, 2007)

*so where exactly would i get one of those??*

Hey thanks for the reply. so where exactly would i get one of those? is that something i can just order from Autozone? doesn't seem like it. 

And any answers as to why it wouldn't come on at all for 16 straight hours of interstate driving, but comes on again once i drive around a bit in the city?

and yes, it's is the VSS error. P0500 on my OBD-II scanner reads "Vehicle Speed Sensor A Malfunc."


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## IanH (Feb 11, 2003)

where are you located?
I have a cluster you could try, if it fixes it then you can buy it


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## Jdoggsc (Dec 25, 2007)

*how do you remove the wiring harness from the instr. cluster???*

so for some reason this error comes up a lot during the summer, but not so much during the winter. either way, when it DOES come on, the ECU almost puts the car in limp mode. maybe i'm being extreme, but it definitely lags noticeably until i clear the code and continue on my way.

I've read forums and, tried the solution posted here http://www.nissanforums.com/b14-95-99-chassis/135606-solution-p0500-vss-speed-sensor-problem.html with *no* success. I gotta get this fixed soon or i'm not going to be able to pass my safety/emissions test next month.

I replaced the VSS before reading on the forums that I never needed to. the speedo works great. it always has.
*My decision:* competely replace the wires running from the speedo to the ECU. I don't want to mess with all those bundled wires, so i'm going to run some dedicated wires straight down from the cluster to the ECU in case there's a short anywhere.

*the problem*: I can't get figure out how to get the wire harnesses out of the cluster without feeling like i'm going to break plastic somewhere, *and* I don't know how to pull a wire from the harness once i do that.

please help!


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## IanH (Feb 11, 2003)




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## Jdoggsc (Dec 25, 2007)

well i already have the FSM and i printed that off, but that still doesn't clue me into how to get the harnesses out of the cluster, and then the wires out of the harness.


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## IanH (Feb 11, 2003)

still working on that, realized wrong diagram.


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## IanH (Feb 11, 2003)

you can unplug the plugs from the cluster 
then to get the pins out you have to use a small screw driver to hold down the clip in the plug


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## IanH (Feb 11, 2003)

why not just cut the wire an inch out from the plug and crimp the new one into place


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## IanH (Feb 11, 2003)

to get into the harness, un-wrap or cut the tape off the end and expose the plastic sheath, poke new wire into it.


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## IanH (Feb 11, 2003)

to get the pins out of the harness plug there is a write up by 99SEL

if you dont have the cluster swap info or cant find it i will send you a link to my files

download "Gauge Cluster Wiring Method"


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## Jdoggsc (Dec 25, 2007)

awesome. you're seriously like the forum MVP. so you seriously just "unplug"ed the harness from the cluster?? do you have to pinch anything in to get it out? I pinched, pulled, yanked on it with pliars, and everything else that looked safe to do and I could not get the darn thing out. I didn't know how else to get it out without standing the risk of breaking the plastic of the cluster. anything i might be overlooking??

how easy do you think it'll be to attach the pins to a new wire i put in there?

Eventually i'd like to do a cluster swap for a cluster with a tach, but not right now--too busy with school for a job like that. i just gotta get this darn light to stay off.


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## IanH (Feb 11, 2003)

the pin is crimped tight around the wire, so its hard to undo without ruining it.

as i suggested why not cut and crimp onto the new wire with a new crimp connector


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## IanH (Feb 11, 2003)

yes push the clip in. If you have a problem with this i will have to take my cluster out and take a picture


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## Jdoggsc (Dec 25, 2007)

so basically what you're indirectly saying, is that there really isn't anything special I need to do to get the harness out of the cluster. just squeeze it hard and yank. I'll try it again tomorrow when i get a chance, and get back to you.


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## IanH (Feb 11, 2003)

yes there is a small lever clip from what i remember press in and wiggle the plug out of the cluster.


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## Jdoggsc (Dec 25, 2007)

got it. before i asked about it, i had only been looking at the far right harness. I couldn't see or feel the clip because the dash light was in the way.


I pulled the harness out and checked it with the wiring diagram in the FSM. it turns out the wires coming from the VSS (R and R/Y) were switched! I followed the wiring on the panel and it looked like pin 21 (out to the ECU) was pulling its signal directly from one of those, so if switched, it could be getting a different signal than what it needs.

I drove about 10 miles after putting them back and checked with my OBD-II scanner a couple times a minute and nothing ever came up. only time will tell if this is solved. generally 10 miles hasn't been enough to trigger P0500 so we'll see.


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## Jdoggsc (Dec 25, 2007)

nothing for 2 weeks! i think this code is over for me (hopefully!)


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