I my experience if you have this code 2H intermittently its usually one of two things. First check to see if the encoder has a linear count using I19 to see it. Try turning while driving to see if unit cuts out and gives code 2H. If it does check the wire harness for the drive motor encoder. Usually the are zip ties so tightly to the drive motor cable that sometimes loosening up the wire harness fixes the issue. If things look good then it could be a drive motor speed sensor. What I do if its an intermittent issue that i can not duplicate I replace the drive motor speed sensor and the wire harness for it and never hear from the customer again :)