#8859, "Another VSS wiring thread" Oct-27-11 10:59 AM by PsychO
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?
#8860, "RE: Another VSS wiring thread" In response to Reply # 0
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
#8862, "RE: Another VSS wiring thread" In response to Reply # 2
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.
#8863, "RE: Another VSS wiring thread" In response to Reply # 3 Oct-27-11 12:08 PM by CODE4
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.
#8870, "RE: Another VSS wiring thread" In response to Reply # 8
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.
#8871, "RE: Another VSS wiring thread" In response to Reply # 9
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.