Cruise control fixed - vacuum line
In swapping out my EGR valve, and removing the battery box, I found the problem that fixed my cruise control. It was a small vacuum line from the bottom of the battery box to the (vacuum tank?) thing mounted above the right side of the radiator. The line was cracked and corroded. Previously the accel button on the steering wheel appeared to do nothing. Now it instantly pulls the pedal from my foot and takes over, holding cruise speed.