Update -

Earlier today, while driving about 30 to 40mph, same thing happened - truck hesitates and 4x4, brake and ABS lights go on and the radio shuts off and turns back on.

Later in the day, driving same speed, again moment of hesitation but this time only the 4x4 light comes on with the radio shutting off then turning back on.

Tonight, again driving same speed, a moment of hesitation - but now I figured out what the hesitation is. It's the ABS engaging momentarily. Even though my foot is on the gas pedal, it feels like I'm pressing the brake pedal for a second. So what's happening is while my foot is on the gas pedal, traveling 30 to 40 mph, the ABS is kicking in for a moment and when it releases, the 4x4 light, plus the brake & ABS light, and the radio shutting off and then turning back on.

Why the heck would the ABS kick in (or perhaps it's the DSC because the system thinks there's wheel slip?)?

What do you guys think?