Panasonic UF8000 Error Codes List page 3 All About this machine Error Code: All codes E1-22 E13 E3-20 E4-01 E4-10 E5-11 E5-12 E5-19 E5-40 E7-90 U01 U13 U16 U20 U90 page 1 2 3 Code: U16 Description: NO CARTRIDGE Causes: 1. No Toner Cartridge. Code: U20 Description: CLOSE ADF COVER Causes: 1. ADF Cover is open. 2. ADF is not installed correctly. 3. ADF Cover Sensor is disconnected. 4. ADF Cover Sensor is defective. 5. LVPS connector is disconnected. 6. LVPS is defective. Code: U90 Description: REPLACE BATTERY Causes: Backup Battery is wearing out.