Speedometer reads wrong even with LS pcm

so i deleted my 97's black box pcm last week, and to my surprise.. my speedometer still reads wrong and my gear indicator light is not on!

the speedometer reads fine until 30 MPH, anywhere after that is 5 mph too fast (used GPS AND obd2 monitor to check)

i used B5 (dark green) labeled "Vehicle speed signal" on the c100 firewall connector for my vss output..(using lt1swap harness instructions for my harness)

i noticed though on my LS harness diagram, the Vss output wire for the speedometer has a description off to the side that reads "4000 pulse per mile signal"..

there is another wire on the C100 connector that (according to the pinouts for c100 via lt1swap) has the same description about the 4000 pulses per mile signal... this one is D4 and is dark green with a white stripe according to the info.

does anyone know if i will get a correct reading if i swap this wire from b5 to D4?

as to my gear indicator light not working, i am completely lost on that one. if anyone could please help out, i'd appreciate it greatly.

here is a link to the c100 plug pinout http://lt1swap.com/1999_vortec_5.7/i...r_end_view.htm

On my LT1 swap I had the same problem with the speedometer, I tried resistors and all kinds of stuff and could not get it to work. I ended up buying a decoder box from Dakota Digital, $90.00 but it's well worth it! It is designed to convert multiple VSS signals, and work with most engine swaps. It's plugs inline with your I/P wiring, as far as the gear selector I have no idea. Good luck with your swap!!!

is your neutral safety switch hooked up? if not that's why your shift indicator light doesn't work.

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Originally Posted by RPM Graphics

is your neutral safety switch hooked up? if not that's why your shift indicator light doesn't work.

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And to where does it get hooked up?

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Originally Posted by RPM Graphics

is your neutral safety switch hooked up? if not that's why your shift indicator light doesn't work.

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i don't think the NSS plugs are all the way in, i might have to drop the whole switch out because that glue is hard to mess with.
i was wondering if there was just some 12v key wire i could tap into for the light

If the mlp connectors are not fully seated, you can use a heat gun to do so.

There are many different speedo calibrations in the ls1 style PCM. You'll need access to tuning software. You can plug in axle ratio and tire size and load the new cal in. Not sure about the decoder listed above, it may also do the trick.

that' i'm not sure of. i'm using a trans from an 02 Camaro & i'm not running a NSS since they're on the shifter in the Camaro & not on the side of the trans.
eventually i'll switch out the linkage shaft & put a NSS back on it. for now i'm not worried about it. i need A/C, control arms, & door handles first.