What is E4 on Canon PIXMA and Other error codes

E4 is Error Code that explain about ink is empty.

E2-2 = No paper (ASF)
E3-3 = Paper jam
E4 = No ink
E5-5 = The ink cartridges are not installed or a non-supported ink cartridge is installed, or the ink cartridges are not installed properly
E8 = Waste ink absorber full, or platen waste ink absorber full
E9 = The connected digital camera / video camera does not support Camera Direct Printing
E14 = The Ink cartridges whose destination are wrong
E15 = Ink cartridge is not installed E16 – Ink remaining is unknown
E16 -E19 = Failed to scan head alignment sheet
E22 = Carriage error
E23 = Paper feed error
E24 = Purge unit error
E25 = ASF(cam) sensor error
E26 = Internal temperature rise error
E27 = Waste ink absorber full or platen waste ink absorber full
E28 = Ink cartridge temperature rise error -
E29 = EEPROM error
E33 = Paper feed position error
E35 15 = USB Host VBUD overcurrent error – USB
E37 17 = Abnormal motor driver error
E40 20 = Other hardware error
E42 22 = Scanner error