John Deere 490E won’t throttle up

Help! 490E caught a stick to the EC or stepping motor. It pulled out a wire which I reconnected and it bumped the motor. Now I can hear the stepping motor buzz when I select throttle speeds but it won't move. With power off the motor can be rotated. With power on it is locked on low idle. Does it need to be calibrated? I've checked all the circuits to all related sensors per the testing manual that I purchased. There doesn't appear to have been any physical damage to the motor but I can't say for sure. I really wish this had a mecahnical throttle! To make matters worse this is a borrowed machine. This always happens when I borrow something. Please help me out. Any advise is greatly appreciated.