So I have 2 modules for 98 passat (for those interested 4d0 907 551 AH) Both of which have AM29F200B (Mask B58755M) chips. Every time I bench read them, a few random bytes get misread and same thing every time I write. This is the same for BOTH. I tried reading at 3/5v, different speeds & etc. So I thought maybe my programmer is starting to weaken up. I tried to read an older 800BB, and it reads it perfectly under 200B memory, and writes. So, assuming the 200b chips are dead, I will try to write the data to a 800BB, and solder that in. I'll come back with results tomorrow for you guys, and tell you if the processor doesn't mind running with a bigger chip.

I'd appreciate any ideas or comments about this.

Thanks, Mark.

Bench flashing has the same outcome, Galleto cable as well as ELM327.

There is only one problem though.
You will probably find that if you flash the ECU over OBD now you will brick it every time.