What would be the best strategy for keeping active fuel management (displacement on demand) less sensitive at highway speeds @ 65 - 70 mph on a stock truck? In particular I'm using OS 12617631 and Cal 12617630 on a stock '08 Avalanche w/ 3.73 gear and stock height tires. Customer wants his AFM (4cyl mode) to stay in longer at highway speeds. I've lowered B0921 to B0936 and raised B0941 to B0960 to open the RPM operating window so that AFM doesn't kick out due to RPM. I get confused on table B0950 AFM Enable Min Vacuum and B0951 AFM Disable Min Vacuum. On B0950, do I understand it correctly that the area under the plot line on this table AFM will allow AFM to be enabled making this plot line the "ceiling" of AFM and if we cross the plot line to the area above, AFM will be disabled? On B0951 the area above the plot line will allow AFM to be enabled and if it value drops to the area below the plot line, AFM will be disabled, making this the "floor" of AFM?

I've tried to raise B0950 and lower B0951. I've attempted to log kpa vs RPM but have inconclusive results to see what is kicking me out of AFM. It seems at speeds of around 70 mph the slightest throttle position movement will kick it out of AFM no matter how big the window may be. Has anyone had success with enabling AFM for longer at highway speeds? Are there more tables than we have access to that affect AFM kicking out?

Thanks in advance for any help.

Jay