LS1 Coupe

I am in the process of doing up my wiring and hooking up my VDO Speedometer but am unsure of how to hook it up. Here is the PDF of hooking up the speedo, I would like to hook it up to the VSS wire out of the ECM, is this possible.

jannes_z-28

This question has been up several times before, do a search and you'll find a lot of info.

In general it is best to hook it up directly to the speedo output on the trans. It will give a sinewave. You will also need a pullup resistor of if the speedo has such a function built-in you have to use that.

The signal from the PCM can also beused if the Speedo can handle a square wave signal. Some can and some can't.

The PCM also need VSS input for different task, especially if you run an auto.


Jan

LS1MCSS

iTrader: (18)

I would try hooking the pcm speedometer output to pin 8. It looks like your speedo can use a sine wave or square wave input.

LS1 Coupe

Thanks, That is pretty much what I was thinking but I didnt want to burn anything out anything, I will try and give the mfr a call tomorrow and see if what they have to say.

jtune

In case you didnt get an answer yet from the mfr, I used the VDO speedo in my swap and ran the vss wire straight to pin 8.

LS1GMCTruck

iTrader: (2)

Would all OBD ll GM Speedo's call for the same wave-signal, since OBD ll was introduced in 1996?

Buckndol

When I was running a 350 with 700 R4 I installed an aftermarket cruise control that ran from a pulse generator ran by the cable. Will the spedometer wire from my computer run this cruise control?

G-Body

iTrader: (4)

Yes, all GM speedos, since they started using electronic speedos in 198? are looking for a 4000 pulse per mile square wave DC signal.

G-Body

iTrader: (4)

The PCM can send a speed signal to your cruise as long as the cruise will accept a 4000 pulse per mile square wave DC signal.

Since it sounds like the cruise setup is a few years old I would guess that it is looking for a square wave DC signal since that was used before the newer sine wave VSS`s came out.