How often can a electronic throttle control malfunction

Well, how often would you like it to malfunction? If you say NEVER, it will explode today! (or at least, that would be MY luck...LOL!)

What your ECT needs is to be PROPERLY DIAGNOSED. There are several things that can cause the hesitation and the light to come on, including faults located in the accelerator pedal position sensors, the throttle position sensors, the Powertrain Control Module, or any of the wiring between them.

There is no "cleaning" to be done. Attempts to "clean" an electronic throttle control unit can totally destroy the unit. This is NOT like the old throttle bodies that could be cleaned out by holding the throttle plate open and dousing it with carb cleaner. To begin with, forcing the throttle plate open by hand can break the gears in the throttle control. Then if you do manage to get it open, the carb cleaner can destroy the electronics.

With all that said, there are a couple of Technical Service Bulletins on your Jeep that involve the ECT light coming on and poor drivability symptoms. At least one of them involves reprogramming of the engine control computer.

It should also be noted here that many of the major components of your engine control system are covered under the federally-mandated 8-Year/ 80,000 mile emissions warranty. Reprogramming of the computer is definitely covered under this provision.