truck speedometer calibration
Thread Starter
Teching In
Joined: Mar 2008
Posts: 2
Likes: 0
From: TEXAS
truck speedometer calibration I put an LT1 out of a 1994 camaro in my 1994 3/4 ton chevy pickup. The speedometer reads about three times the actual speed. I used the CATS tuner to calibrate the speed to the tire size and gearing in the truck first, then played with the actual ratio without any noticeable difference in the speedometer reading. The vehicle speed sensors (VSS) are different in the two vehicles, and they are not interchangeable as far as I know. There is a VSS buffer behind the glove box that may have something to do with this. I sold the original truck computer with the engine that came out of the truck, and I would like to calibrate the speedometer without having to purchase and install another truck ecm. I will get another truck ECM if I have to to make the cruise control work. If anyone has had similar difficulties, I would appreciate your input.
Joined: Sep 2004
Posts: 3,148
Likes: 12
From: Downers Grove, IL
I thought both of those vehicles use the 40 pulse per rev sine wave senders. The trick is that you have to hook up the 2 wires from the VSS to that box under the dash (DRAC) you will have to tap into the wires to do that. Then you have to recalibrate the DRAC box using the info on this web page http://www.614streets.com/drac.html
Thread Starter
Teching In
Joined: Mar 2008
Posts: 2
Likes: 0
From: TEXAS
Alright, I haven't tried that. I've had the VSS signal going through the ECM before the DRAC this whole time. I don't know if I'll get around to it tomorrow, but I'll definitely give it a try and see what happens.
