Originally Posted by
RobertISaar
guys, you're overthinking it....
there are multiple places in the BIN that define cylinder count.... some are for certain operations.
the one with the 0/128/192 is for engine speed and airflow calculations, the number itself is actually a 0-1 multiplier, 128 is half of 256, therefore, it's used for 4 cylinders. 192 is 6/8 of 256, therefore it's used for 8 cylinders.
the original calculations were done assuming a V8 engine(or at least that's the max GM wanted to be able to control) with 4 pulses per revolution on the reference circuit from the ICM, that's why the multiplier is needed. if you wanted to run a single cylinder, you could change it to 32, 64 for 2 cylinder, 96 for a 3 cylinder, etc....
the other one, the bit encoded value, that's for DTC and limp-home operation, and i think nothing else.
so, the XDF really needs to have both locations and both with tips if running anything other than a MPFI/TPI V8.