One thing question is the 4.8v stated as the upper end scale. I think it should be 4.5v, but I dunno. It?s set to the scaling that can be found on diesel parts websites that sell them.
How far off is it from your Baro sensor reading at engine off? Just an FYI, Cummins ECM?s do funny things with the MAP sensor reading at key on and startup at times. Mine will at times read lower than baro at key on and get worse after engine start but if I turn the key to on, wait a few, key off and wait a few then key back on it will match baro reading and hold matching baro reading at idle after start.