Error e -070 in canon ir -3100 color copier

Its an error with the senor for the transferring belt. Try going into the additional functions-adjustments/ cleaning-gradation adjust- full adjustment. And follow the prompts on the screen. If this doesn't work and you feel comfortable trying you can clean the sensor. Remove the front covers, waste bottle and the drum. The sensor is located inside the chassy where the drum was at, in the middle (front to rear) on the left Do not use a vacuum on the sensor it can be damaged easily. After cleaning and reassmbling retry the gradation adjustment.