Vss signal loss issue

For the white truck, I just moved those 3. The red truck is sequential injection with boost control and such running through the harness, so I did a lot of wire moving for it.

One quirk I noticed looking back through my data logs is that my VSS drops from 2.5 mph to 0 every time. It never logs a speed on the way down between 2.5 and 0. However, it always shows speed correctly when accelerating, so it logs speeds between 0 and 2.5 when I start rolling.

I will try to get a data log with the rebuilt PSOM today to see if it does the same thing.
 
Ok cool thanks. Yea mine will spike when it hits zero. I'm going to try and see if I can datalog now that I have made some changes to see if it spikes and come back or if it spokes and holds then comes down
 
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Rebuilt PSOM does the same thing, and I watched it in TunerStudio while I logged it. When I come to a stop, the VSS reading sits just under 3 mph for a notable amount of time, maybe a half second, before it drops to 0.

Can you post a log here? Or send it to me at fmosracing at gmail?
 
Not sure I'll be much help here, but I only moved the 3 wires in the startup guide. I haven't seen any issue with my speedo other than the MPH is about 3-5 slower than my actual dash reads even though I have all the settings correct. I haven't watched the logs on the VSS to see how it reacts though.
 
Not sure I'll be much help here, but I only moved the 3 wires in the startup guide. I haven't seen any issue with my speedo other than the MPH is about 3-5 slower than my actual dash reads even though I have all the settings correct. I haven't watched the logs on the VSS to see how it reacts though.

Have you watched the speedo vs tunerstudio vs GPS?
 
Yes I have compared them… truck and GPS are within 1mph, but the TS speedo reads within 2-3mph at lower speeds and by 60 it reads about 5mph slower. I’ve tinkered with various settings and that’s as close as I could get it. Since it doesn’t affect actual mileage on the truck I haven’t been too concerned with it.


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