[section525]

This is what someone said about it:

I've done a little research of my '95 and '99 manuals, and the best I can figure out is my first guess was incorrect. It seems that that the VSS and the RABS may be quite similar. They both generate an AC signal which increases in frequency as the vehicle speed increases. It appears that the frequency is the same between them (65 Hz @ 30 MPH and 125 Hz @ 55 MPH). However, in the testing procedeure, it states that the VSS should generate a voltage between 1.0-5.0 V, while the RABS voltage should be between 100 mV-3.5V. Even though the RABS is producing the correct frequency, the lower voltage may not be strong enough to produce a trouble-free signal for your situation.

Edit: Something doesn't seem right, but I can't put my finger on it. The '99 lists the frequency given above as a "VSS" signal, but it doesn't have a VSS. The signal from the RABS is input to the 4WABS, then the 4WABS sends a speed signal to all the various components which require it. I don't know if the frequency given is the raw RABS signal, or the output from the 4WABS. My gut feeling is the frequency from the RABS is much higher (if I remember correctly, the toothed ring the RABS uses to generate a signal has 120 teeth) then the programming that is done to the computer correlates this raw signal to the frequencies required for the VSS signal. I do know that the more I look at it, the more confused I become.

Maybe you can help interpret it for me! Thanks!