Arkie, The flash to let you not touch the +/- button, the 400/800 etc was all in the Sept 2010 flash. The spring time flash this past April is the one that addressed the DEF tank level, transmission shifting issues etc. I have the 400/800 flash. I just hae not gotten the spring flash. And what it addressed about the DEF tank had more to do with it being less than half and you put in a gallon andnot totally filling it, so that it still reported less than half even though it might be 3/4 full.

 

The flash I received must have incorporated all of the above. Definitely improved performance and efficiency. I like it.

 

I am still not clear on resetting the DEF system. If I add additional DEF before I get the 800 mile warning, but do not fill it to full, will the system register the addition, or will I get the 800 mile warning, even though I have adequate fluid in the tank? I would rather put the remaining fluid in the tank than carry around a partial bottle of the stuff in the truck.