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Old 01-06-2013, 02:02 AM   #1
yossarian19
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Neutral Safety / PNP switch ??

I've searched a bit and am not finding the info I am looking for.
What I think I remember reading is that the PNP switch has three functions. One, reverse lights. Two, keeps engine from starting in anything but neutral or park. Three, adjusts idle speed by 100 rpm or so depending on if you are in neutral or drive.
The GM rep at SEMA said the PNP wasn't really necessary for a swap.

The harness I have uses 2 connectors for the PNP switch. Both are basically toast.

So at this point, do I get rid of the PNP wiring? If so, can I do anything to get my 100 rpm idle increase while in drive?

What else am I missing?
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Old 01-07-2013, 03:56 PM   #2
OldCreek
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Re: Neutral Safety / PNP switch ??

Whether the 100rpm info is true or not, I suspect you could find the two connectors at a auto salvage or online. There are websites that will sell them. Moreover, you could probably go to a Chevy dealer and have them order these parts for you.

I have heard of guys using the stock pnp switch on the column, only. I use both... I wire my reverse lights and ignition from the stock column switch and leave the 4l60e tranny switch connected to the pcm. My knowledge on this subject is limited so do some more research...
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Old 01-14-2013, 01:09 PM   #3
mrhurt73
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Re: Neutral Safety / PNP switch ??

i am not sure of the exact pin-out, but i do know that the connection to the 4L60E tranny requires heat to get connectors loose.

found that out on my build after i almost destroyed the connector.

add heat they come apart easy.
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Old 01-14-2013, 02:23 PM   #4
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Re: Neutral Safety / PNP switch ??

I don't run reverse lights or an NSS/PNP. Then again I didn't run seatbelts, hood, or winshield for a while

IIRC the "100rpm" thing is somewhat true, tho I'm not sure if it actually makes a difference. My tuner said that it was a function of load and the knock count /lockup. It only does so to prevent feeling the "clunk" into drive, and the occasional "dip" in rpm from the drivetrain loading up. When I put mine into gear, you feel it load up, the rpm MIGHT dip by about 50 for half a second before it catches itself. Thats it.
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Old 01-15-2013, 07:26 AM   #5
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Re: Neutral Safety / PNP switch ??

check out this thread HERE




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Old 01-15-2013, 08:16 AM   #6
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Re: Neutral Safety / PNP switch ??

Yossarian19, I Believe the gm rep was correct. I just used the factory wiring for the reverse lights an saftey neutral. I have a 04 pcm and my tunner told me it watches for load. When it sees load it adjusts accordingly when it sees a rpm drop ( a/c , put in gear ). Not sure what year you have but it may do the same. Might want to look into it.
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Old 01-15-2013, 10:37 AM   #7
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Re: Neutral Safety / PNP switch ??

subd
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