MrVette90l98mt

Hey guys, I'm coming over hear from the C4 tech forum in search of Vehicle Speed Sensor signal type and details from an OEM Corvette LS3 manual transmission. Why you may ask? I dropped in an LS3 EROD kit in my 1990 vette ZF6 Manual trans and I cannot get a speed reading off of my ECM (E67 I believe) through a scanner.

My question is: Can somebody explain all the details regarding an OEM LS3 manual transmission Vehicle speed sensor on corvettes?

AC sine wave?
Square wave?
voltage range?
How many pulses per revolution and per mile?
Is the signal converted or manipulated before going into ECM?

I want to understand what the ECM is wanting to see for a VSS input. I need this for CA smog.

More details on my previous post:https://www.corvetteforum.com/forums...post1594150507

Thanks in advance!

needcheese

I don't have all the answers you are looking for. The speed sensor you are asking about is actually located on top the differential in the C6. I believe the sensor get its pick up from the teeth on the ring gear.

TTZ06VETTE

Believe it is 0-5v square wave and 4000PPM. If you can tell me the year and make of the vehicle I may be able to get you the ECM/BCM pin and wire color as well.

torquetube

From the C6 shop manual: "the VSS is a permanent magnet generator that is mounted on the transmission and produces a pulsing voltage. The AC voltage amplitude and frequency increases with vehicle speed."

The official test method appears to be spinning the drive wheels by hand and looking for ≥ 0.5VAC from the VSS. Not exactly a NIST calibration procedure.

That's as much detail as I have. Probably the best way to further characterize the signal would be to attach an oscilloscope to a C6 and go for a drive.