I’m running a 1227808 and I found some information on running two different bins the document said replace the 27c128 with a 27c256 and stack the bins then to run a switch from 12+ to pin C9 on the ECM and when 12 volts was applied the EPROM at pin 27 (A14) is switched high by
the ECM and when power is taken away the ECM switches the EPROM low.
Now I’ve tried this and haven’t had any success getting it to work can anyone confirm this is correct I assume it must be the same for a 165 ECM as they are pretty much the same.

 

Not sure what you are saying. Never apply 12 volts to any stock EPROM address, data, or control line unless you are trying to program it.

It sounds like you are trying to do bank switching with A14. Use 5volts only for tying it high.

 

i'm not applying 12 volts to the eprom i'm applying it to ping c9 con the computer and it is supposed to switch pin 27 with the correct voltage, it was apparently used on the cars that ran lpg to switch between programs but i can't get it to work

 

That sounds neat. It is new to me. Sorry I can't help.

 

On the '165 it looks like the code itself would need to monitor the state of the C9 input. I don't see anything hardware wise that would cause it to switch A14 to the EPROM. Doing this in code is feasible.

RBob.