Hi everybody just looking for schematics wiring diagrams for a 1994 Corvette Base Model .Looking to bypass CCM with a signal generator to pcm to enable fuel and spark.
Hi everybody just looking for schematics wiring diagrams for a 1994 Corvette Base Model .Looking to bypass CCM with a signal generator to pcm to enable fuel and spark.
just so you know you can switch one bit (and 2 bytes of checksum) and your ecm will no longer care about that signal.
the tools to do so are free on my site (see my signature)
CCM controls starter relay on y-bodies, so it will take a little extra effort to rewire the starter to the ignition switch.
Going with the signal generator a 40-60hz signal will make the pcm happy.
kuro I have bypassed the start relay already and purchased the 30-50Hz generator with 30-50 alternative signal and cannot dial in which wire at pcm to cut and splice in the signalOriginally Posted by kur4o
Layman's term Please and Thankyou I am a Newb to flash and programming but love fixing cars it is my Trade .I have no cert's but been surviving in the Industry for 10 plus year's as I was taught from a young age and mentored by my step dad an ASE Master Tech .Only Issue is like almost all Tech's I see are not good with DVM and chuck part's at it .Not my style
Please Help YOU GUYS ROCK
The signal goes to pcm pin A25[red connector]. Make sure it is 0-5v signal.
kur40 Do I jump off the pin if their is no wire in either location specified such as A -19 on 93 and A25 on 94.Apologies in advanced im sure you have answered this a million times......
Just feed the signal there. If there is no wires put a new pin in the connector.
awesome thank you .So I used an airbag pin I had and modified it. Didn't check it with my 80's analog scope not sure if it will even work 4 reading this stuff correctly but for now DVM reads 9.3 milla volt key off 5.0v key on .One last thing is well 2 .1 Do I need to ad capacitor or resistor to signal wire ,I read the signal wave form might need slight mod .The one I have flashes blue led and is a waterproof PCB circuit with smt technology off Ebay 4 settings but wasn't positive enough which one . You said 40-60 Hz so I will use 50 Hz but would I use 50 Hz Regular or alternative .
I can not thank you enough for fast response, helpful.
I'm ready to donate
It might be a little more complicated. There is also some digital data exchange between ccm and pcm via aldl on y-body calibrations.
You can give it a try with the signal generator, trying all possible settings you have. I haven`t seen a scope capture of the signal, but it must be similar waveform to a maf sensor output. I can only suggest that the regular is square wave output and alternate is sine wave output. Than you can try first the alternate.
If the engine starts for a second and dies, it means the vats is still on.
If all that attempts fail you will have to reflash the pcm.
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