I am building the 50Hz generator for the vats, anyone know how many volts the 50Hz signal is that goes into the ecm to disable vats?

 

It looks like you and I are in the same boat right now. I built the 50 Hz oscillator according to plans available at the URL I provided in an earlier posting, and set it up to operate whenever the ignition was turned on, running the output wire to ECM B6. The output on mine registers as 10.4 V, but the ECM pinout check diagram indicates that B6 should read 2.5 V. I am not familiar in the manner in which oscillator ouput registers on such an oscillator, and it doesn't seem that my frequency meter (a simple feature on the $40 Craftsman multimeter I am using) is capable of measuring the output of the circuit. Maybe I just built the thing wrong, but I went very carefully by the instructions on the website. I still got the VATS code, the engine wouldn't run, and nothing else changed. I still would like to make this method work. If you are more familiar with electronics than I, which you probably are, and are able to come up with a better method, or if you have success with the one I have already found, please let me know how you accomplished this and how things come out. It looks for now like I am going to go ahead and put the money I have coming back from project items I didn't use toward a PROM burner. That may provide the greatest returns in the future, and I think that the investment is acceptable. I'd be very interested in seeing your project, and would appreciate your sending me a picture or two if you have any in JPEG format. You can E-mail be directly at cweddle@neo.tamu.edu if you would be interested in discussing anything else.

 

I am interested in what both of you are talking about/ attempting to accomplish. I have a 88 chevy c1500 that was originally a 7747 ecm, it has since been converted to a 8625 pcm for controlling both the engine management and the 4l60e transmission. I am currently in the process of modifying the manifold for MPFI while using the existing throttle body for air purposes. I have not decide to try to use a 7730 (not a pcm), or attempt to use my TBI manifold to drive the individual injectors. Anyway, I have a burner and TunerCat. I don't have the tdf for your ecm however. like, put up for the tdf and I would gladdly burn a prom without the VATS for both of you. I would also be interested in details about either one of your trucks. Email off board at: gdkng@hotmail.com,

gdkng

 

it is supposed to be an 5v ground singnal meaning the ecm sends 5v and the vats grounds it. on of on of that all the vats does with the ground thats why you need to ground the relay keep in mind it will need to be a 4 pin relay to avoid current flow from the vats simmulater you made.

 

That is correct on the 4 wire signal generator. You must have 2 grounds, 1 wire for the crank signal(this is from pin C9 on the 7747 ecm,which is your power for the oscillator,) and a wire to the vats wire that goes to the ecm.The vats wire should be blue and in location F10 on the 7730 ecm. Don't have my truck running yet, but I hope to hear it purr before the end of the week.