Anywhere here ever used the VSS wire on a 2005 Saturn Ion?
The VSS wire I used was on the PCM, blue connector, yellow wire(Very high frequency Sin wave). This wire comes from the transmission output shaft sensor, which has 2 wires : Yellow(Speed sens High) and Purple (Speed Sens Low).
The problem I am having is there is no signal below a certain speed(around <20km/h). The amplitude of the signal from the Yellow wire varies with speed.
How does this transmission sensor work? Is it that at lower speeds, the purple low speed sens will send out a signal, then at high speeds, purple goes dead and the yellow High speed sens will send a signal?
I have included a picture where I connected the VSS wire. I no longer have access to this vehicle.

The Yellow and Purple wires are the speed sensor wires off the transmission and don't work well for a cruise on this car. Most cruise controls would rather see a buffered signal from the PCM. This signal would be a square wave. If your cruise control can be set to accept a sine wave input, it may work using the mentioned wires but not likely from my results. One of the wires is a reference ground and the other is the sensor output. I have done a few of these cars for cruise and I add a magnetic speed sensor assembly to the front drive shaft. It gives the cruise a smooth and reliable speeed pulse signal to work off.
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sparky
Saturn ION
’03
VSS: At Speed sensor, 2 pin plug,
Wire Color: VIOLET 48,000 pulse
’04
VSS: At 20 pin connector on transaxle, Pin 2
Wire Color: RED / BLACK 48,000 pulse
The SCS/Frigette cruise control SCS4342 available HERE, can easily handle this signal and give the absolute smoothest operation of any cruise control on the market.