pcmhacking.net

Hello

I have a problem because I installed a turbocharger for the car and needs to change the MAP SENSOR scales in the fuel maps.
Needs X / Y scales to 29 psi.
How does the MC68HC11 processor read the fuel and ignition map from the EPROM memory?
Thank

This looks very similar to the delco hc11 based systems from the 90s. The code and maps will be in the eprom. The reset vectors are at the end of the file. You'll need to read the memcal (eprom) and find a product that can tune the bin so you can observe the changes, or disassemble the code yourself, or identify maps by eye and shape. There is also likely a checksum you'll need to find and calculate correctly or disable. It may be possible to disable it by setting the program id which may be at byte 8 to AA the same as you can on the older generations, or it may have changed. Look to replace the memcal ic with an eeprom and make up an adaptor so you can plug it straight in to a programmer. You'll likely need to do that quite a number of times to figure it out.