VSS Sensor into radio?

[savagedl]

Regarding the recent wire diagram posting:

The Mach diagram (right after the one that shows the sub amp) shows Vehicle Speed Sensor on connector C228. What's the VSS doing in the radio harness? The Gray/Black is right there on pin 9 on my 2000 Explorer.

I'm interested cause I have another device that taps VSS under the hood. Would have saved alot of trouble if I'd known it was also right behind the radio.

 

[Cobraguy]

There are VSS signals all over the car. There are many things that utilize that signal. Even the overhead console utilizes it. The message center, windshield wipers, speed control, ECM...lots of things...including your radio. On your 2000, the signal is generated from any of the three ABS sensors, sent to the ABS module, and distributed from there. As long as you have one ABS sensor, you get a signal. For your radio, it uses the signal to adjust the volume of your radio automatically as your speed changes. Speed Sensitive Volume Control.

 

[savagedl]

another vss question

Thanks Cobra. Another VSS question? My other application is a distance measuring device. I recently changed from the rear differential ABS sensor because counting had become unreliable. Changed the ABS sensor and remade connection under the hood, no change. Manufacturer of the device suggested using VSS feed. It works fine EXCEPT real sporadic under 3 mph. Manufacturer says VSS output is not reliable under 3 mph and I need to live with it or sense some magnets epoxyed to the drive shaft. Do you have any knowledge of the VSS low speed accuracy?

I know this is outside of the forum intent, but I'm having trouble finding people that REALLY know!

 

[Cobraguy]

I haven't heard of that problem under 3 mph. Doesn't mean it doesn't exist though. But it does surprise me.

Magnets to the driveshaft are rarely a good idea. You have to get them in the EXACT location called for or they are unreliable. If one falls off, you not only lose your signal, but you also can have a balance problem.

Have you tried connecting to a VSS signal that is downstream from the ABS module and see how that works? Might be worth a try. Is this a G-Force meter (or similar) you're trying to hook up?

 

[savagedl]

Right now I'm tapped to VSS just outside the ABS connector (I think) on the driver side under the hood. I'm going to try the one in the radio connector.

Jamar, RAC-200 (http://jamartech.com/DMIs.html) lets you measure/record distances in feet/mile/meter/km from inside the vehicle. Used in highway engineering. Typically accurate to within 5' per mile.