Trouble code P0851

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oldpro
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Location: New Mexico

Trouble code P0851

Post by oldpro »

My check engine light came on this morning and the Auto Zone tech said it's "neutral switch input low." Might be a loose, short, or open circuit, a failed neutral switch, or a poor electrical connection. Hey; it's a 5-speed manual. I thought only AT's had a neutral safety switch. Where might such a switch be located on a MT?
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anarchy1024
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Re: Trouble code P0851

Post by anarchy1024 »

So, it looks like the MT has a Neutral Position Switch (whereas the AT has a Park/Neutral Position Switch). Diagram attached of what I think is for the 5MT.

I'll see if I can find the diag procedure for it. I remember that Part Source (and possibly AutoZone) used to print diagrams and instructions from some mechanic's software a while back. Do they still do that?
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neutralswitch.PNG
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anarchy1024
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Re: Trouble code P0851

Post by anarchy1024 »

Diag procedure for MT.
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p0851mt.PNG
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oldpro
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Re: Trouble code P0851

Post by oldpro »

Wow! Thanks so much for the info. I'll crawl under there this morning and check out what I can. Knowing where the switch is, is a big help. Depending on what I find, I may have to go to a "professional" for help or part replacement. I hope it's a loose connector.
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anarchy1024
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Re: Trouble code P0851

Post by anarchy1024 »

No problem, happy to help when I can. Let us know how things go.
oldpro
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Posts: 78
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Re: Trouble code P0851

Post by oldpro »

I called an independent Subaru repair shop and they told me to bring it in; they'd check the code, reset it, and I should drive it for awhile and see if it recurs. It did, and I'll take it back next week for them to do a more thorough diagnosis.
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