I have and ETR 335D that had a new traction motor installed onto unit. After installation of traction motor code 1504.01 came on and is intermittent on and off as soon as key is turned off and recycled code will go away and take anywhere from and hour to two hours to come back on. Any ideas on what is causing this code and could it be related to the installation of the new traction motor. Any help would be appreciated.