I posted this before. Now trying to post in the right place.

This is how I found the VSS wire on a 1999 Lexus Sc300.

You have to find the ECM. It's located under the passenger side dash. You have to peel the floor carpet back. You will see 2 screws that you can loosen.

Here is the wiring diagram that I used to find the VSS wire. It's the one near the top left. Light Blue with Yellow Stripe.

So if you look above you will see a "C". The "C" references "E17".

The 5 means the position it is in the harness. This is the wire to tap into.

Finally this is a picture of the acutal wire you need to tap into for the VSS. I got this from ClubLexus.com.

Good Luck and I hope this helps.

Did u happen to know about VSS on 1992 SC300?

I would check on Clublexus.com under forums.

Wow thanks