Max power available for cruise control?

[Zoomit]

Driving home today I was climbing a steep (10-12%) grade at 55 mph into a 30+ mph headwind. The cruise control was engaged, that is until it unexpectedly cut out. The car slowed quickly and so I floored the accelerator before getting rear ended. The steady power requirement was probably above 50kW.

Is there a limit on how much power the cruise control can command? If so, why would it just cut out instead of slowing down and displaying a warning? Unless I unwittingly pressed the brake, I can't think of any other reason for the cruise control to turn off.

 

[greenspark]

From the manual:

When going up steep hills, you
might have to step on the
accelerator pedal to maintain your
speed. When going downhill, you
might have to brake or shift to a
lower gear to keep your speed
down. If the brake pedal is applied,
cruise control will disengage.

It seems that they did not update this section for the EV, so ???

 

[Zoomit]

I figured out what was going on. I experienced the same phenomenon again today on the same section of road. The car turns off cruise control when the traction control initiates.

The scenarios is this: On a steep hill, the torque output is high to maintain speed. A few areas of this road have large bumps that 1) cause the front tires to jump due to the torque output which 2) turns on traction control and 3) disables cruise control.

This is somewhat dangerous because the car decelerates quickly because of the steep hill and sudden application of regen. (I always drive in L mode.) I almost got rear-ended the first time this happened. Today there was no traffic behind me.