Corvette CCM Reverse Engineering Anyone?

[NomakeWan]

Yes, I understand and I will post my GM documentation when I find it. The Mefi4 is very very similar to the obd1 LT1 computers electronically and when I need to convert a 4 into a 4a or 4b this is how we get it into boot mode for programming the entire 256k and not just the calibration data, and yes, still ground for diagnostic mode. Maybe this doesn't work on the LT1 computer but I bet it does. I only have obd2 LT1 puters here or I would already know :)

I look forward to seeing that documentation. What I have on the CCM (as posted earlier) says that the "secret" pin for resetting EEPROM values is internal to the CCM, not something that can be accessed externally via any means. This makes sense since the CCM controls the odometer, and you wouldn't want someone to just be able to plug a stolen GM tool into the ALDL port and change the odometer at will.

NomakeWan can you make an updated dump of the ccm you have. Hope thay gathered some mileage, so we can identify some stuff pretty quick, if the eeprom increase at some places.

Here's a fresh one from my '95, taken just now.