Hello all,
Let me start off by saying that I have read every VSS thread on 2gnt at least 3 times. I have converted from AT to MT but have been unable to get the VSS to work. I've been driving with no speedometer for quite some time now.

Car:
97 avenger (AT to MT), 2.4 swapped.

What I have done:
Wired the VSS according to Corbin's write up (solder and shrink wrap).
I spliced into pin 43 and 44 as they are shared.
I wired the VSS to pin 66 directly into the wire coming from the ECU plug.
Removed the TCU under the dash.
I still am using the ATX ECU.

What I have done to diagnose:
I have tried 2 different VSS'.
I used a digital multimeter on the plug at the end of my wiring and here are my findings with the key to ACC
-Ground on pin 43 (left terminal if latch is on top - black w/ green)
-I am receiving 9v to the plug on pin 44 (middle terminal - yellow)
-I am also receiving ~5.60v to pin 66 (right terminal - yellow w/ white)?

If I plug a VSS into the plug (out of the tranny) and spin by hand, the voltage on pin 66 drops to ~5.50v.

And just for the hell of it, I tested the other end of pin 66 (the end that goes into the harness) and I have 9v? Shouldn't it be 0 as it would be going to an empty plug that was used by the ATX?

I think i've covered all the bases, but I'm lost.

Does your speedometer react when the gear is spun by hand (and the dash has power)?

You have it right:

Yellow: 8 volts according to FSM (runs on a variety of voltage sources though, I have mine powered by +12v)
Black/Green: Ground
Yellow/White: feed to dash speedometer

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2012 2500HD LML

Are you sure your plastic diff gear is still on there intact?

Captain Caveman

96 RS Turbo 11.414 @ 119.62 MSNS, Crower 2 NA cams, BW366, 10.5 comp, UDP, 60mm TB, W/A intercooler, 3.55 tranny 567.9whp 430tq
97 RS NA 13.188 @ 103.87 MSnS powered 12.5 comp, Crower 3's and 219.4whp with 175tq
98 RS DD 12.5 comp on stock ECU, LTH, Crower 2's, Koni, GC, Hypercoil, DG hats
99 OZ 5sp Stocker 15.856 @ 85.97
99 GS stocker auto 17.7@77mph!

wiki home page:http://www.2gnt.com/index.php?d=bullettdsm

The speedometer does not react when I spin the gear by hand. I have tried both VSS' with no luck.

I also put the VSS back into the transmission and drove the car and still nothing...

Is the voltage on pin 66 correct, even though the car isn't moving (or when i'm not spinning the gear by hand)?

What really confused me was when I saw 9v on yellow w/ white leading into the harness where I thought it would just end at a connector that was not connected.

yes, the white/yellow signal wire outputs a square wave with a peak of about 5 volts. If you have access to an oscilloscope and spin the gear by hand, a healthy sensor would output a perfect square wave pattern.


hmm now that I think about it, back when I rewired my full engine harness (1999 model) and removed the OBDII harness, I remember (2) white/yellow wires from the ECU to the harness that eventually went to the dash. When I installed my own harness, I wired the white/yellow from the speedo sensor to both of those wires from the dash. Not sure why there are two though... I checked the continuity from the engine bay end, and both wires went to the same location. I tied both together for safe measure.

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2012 2500HD LML

I tried a second cluster, no luck.

I'm going to open up the harness leading inside the cab in search of a second yellow w/ white wire.

So there are two...

One the comes from the main harness that comes through the firewall and splits off to a connector behind the radio, than goes up behind the dash.

The second comes down from the dash, goes to a connector just to the right of the other and goes back up towards the back of the dash again.

So I ran the signal wire and spliced into both inside the cab and still nothing.

Does is matter that I'm still using the auto ECU?

The only thing that I can think of is that both of the vss' I have are bad.

Possible. Speedometer is not dependent on ecu - mine runs fine without any ecu in the car.

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2012 2500HD LML

I know it works with the auto ecu. Check the auto trans wires. Possibly you put a wrong wire in? Never hurts to double check it. All you need it 5 wires I beleive off the auto. 3 for vss and 2 for reverse. Try plugging the computer back in under the dash.

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99 Eclipse gs (Daily)
89 Honda Crx (Drag car project)

That one thing I haven't tried, only because every thread i've read says to make sure it's removed..but at this point i'm willing to try anything.

I purchased a brand new VSS from the dealer, still didn't work. And this is spinning it by hand, looking at the speedometer.

I've read every single VSS thread 5 times each (a lot of reading), double, triple and quadruple checked my wiring (continuity through the wires, volt meter, etc).

What I really don't understand is why i'm getting ~9v from the VSS wire coming from the harneess, leading into the ECU (pin 66) for the VSS signal. Where is the 9v coming from? I assumed it went to a plug for the ATX. Stumped.

I really don't care about the speedometer or the odometer but the dying at red lights...is aggrivating.