I have a problem with my project. A friend burned a Prom for me. But i keep getting errorcode 24. I have a 305TPI 89 converted to a 305TPI 90 with a 7730ECM. I have mounted a VSS from Stealth Conversion (part# 2PRS), it´s a 2pulse squarewave. (i get a signal at the ECM so there is no problem with the connection). How do i get it to work with my 7730ECM ???? Please help me. Thanks Jonas

What pin(s) is the sensor connectd to? Are you getting a reading in the datastream(if you have access to a scanning device)?

The 730 was used with two different types of VSS. So you need to find a schematic, to be sure you have it wired up for an optical sensor rather then the magnetic. Then there is a switch that needs set in the code to indicate which one your using.

Why should i use the optical setup when the VSS is magnetic ???

It gives two pulses without any external powersource....

At the ANHT hac you can see at the “AFR OPT WD 3” (AFR mode word 3) that the bit 6 = MAG SPD SENSOR INSTALLED so you can check for your application if it is at the same place and select the option.
I think that this is what Gumpy mention.
regards,
Cobra289

You'll have to ask someone at GM, about the terms they use. I was just telling you how to get it to work.

In your original statement you said it was a square wave, which is not indicative of a magnetic sensors output.

Ok, a two pulse VSS give 2000 pulse per mile and that was used on the TPI from 85 till 89 if you have converted to a 90 ECM you need a four-pulse sensor (4000 pulse per mile) used by GM from 90 till 93 those sensor give a Sine Wave and it is translated to pulse for the ECM by the DRAC module.
Therefore, what you need is a DRAC module that translates toe 2 pulse to 4 pulses.
This site covers everything that you need to do to get results.
http://webpages.acs.ttu.edu/chdarby/DRAC.htm
I hope this will help you.
Regards,
Cobra289

Cobra is right, the 730 setup is wanting 4 pulses per mile.
Maybe you can exchange the one you bought.
I used the "4PAC" unit from them to drive the mechanical speedo and has the built in pulse generator.
The ECM outputs the 2000 PPM to the cruise control.

Quick thought for anyone who might know,
There is a setting in the bin for VSS pulses per mile at location 15.
Could this just be set to 2000 and make it work?
I'm not sure. If you are able to give that a try might be easier than climbing underneath.

There is also a "vehicle speed instrument panel pulse divisor" at position 14. (according to the super 8dm1.ecu file)
What is that for?
JP

I bought the VSS from Thirdgen resource and i said i wanted
one called 60116 but it seems that i recieved a 60115 instead, the problem is that i live in Sweden and it would take me most of the summer to get it exchanged......

I probably try to get the right one here (for about $150).....

If there aren´t any possibility to use this one i already have or if it possible to use the speedbuffer thats inside the instument cluster???

For $79.90 you can buy a better product from Dakota Digital the SGI-5. It is a transducer that makes changes from 2 pulses to 4 pulses, in your case you will use to feed the ECM the connector “OUT4” this will give a 4 pulses output.
It calibrates your tires size and you can go back to the 2 pulse if you want.
http://www.dakotadigital.com/Detail....-5/product.htm
Download the instruction manual and you will see the capabilities.
In addition, other option is go in Sweden to one of the truck shops for the European Tachograph or taxi shops they have all this kind of instruments (Speed Sensors) I found one here in The Netherlands.

I thought I have seen some post here about the SGI-5, do a search to check other people experiences.
Regards,
Cobra289

Flip the byte in the bin to optical speedo input (2000 pulse) and wire it to pin BC6 on the 730.

< snip > from Mike Davis's site.

'165 Harness '730 ECM
------------------------------------- --------------------------------------
A1 (Fuel Pump Relay) BA11
A2 (AIR Valve - Port) GF2
A3 (Evap. Canister Purge) GF7
A4 (EGR Cntl) GE9
A5 (SES lamp) GE7
A6 (IGN +12v) BA6
A7 (TCC solenoid/A4) GF6 (Automatic Trans)
(Shift light/M5) GF1 (Manual Trans)
A8 (ALDL Serial Diag) BA8
A9 (ALDL Diag Term) GE12
A10 (VSS {buffered}) BC6 (requires PROM change: Mag VSS
at 0x18 b6 for $8D PROMS)
A11 (MAF Analog GND) N/C
A12 (Sys. GND) BA12

http://www.eecis.udel.edu/~davis/z28/ECMs/86to92.txt

This will allow your 730 to work with the 2000 ppm square wave input.


BW

Sounds great, i will do that

Thanks alot....

That was the solution i was looking for, my vert works
perfectly now, thanks again

//Jonas

No problem. Happy it worked it out. BW