Accelerator failure

2001 MB E320. While traveling at the posted speed, 75mph the accelerator quits working. The speed control will still work and the accelerator will work after some play and time. When I stop the car and turn off the ignition and then start the car agaiin the acellerator works fine. This has happened only twice but I’m afraid it will continue and happen more often. I traced the accelerator cable to a small box on the left side pf the engine.

Anyone have an idea?

According to the prints, you have a accelerator pedal position sensor. This controls the throttle through the computer. The computer drives the throttle valve motor. It could be either the pedal position senor or throttle valve motor are bad.