This error is very common and can be fix just by updating your firmware to the latest version. Each printer had their own firmware once installed on your computer. You can download or update it from the link provided below:
If the printer is still under warranty, you should bring it back to the Canon service center to service it again. In Canon printer, error code “E225” means the intensity of the lamp light is not sufficient. To fix the problem, try to turn off and then turn on the printer several times. See if this works. If this doesn’t work, you have to check it manually.
Check the connection between the main controller PCB and the CIS unit. If this doesn’t work, replace the CIS unit. If the problem continues, replace the main controller PCB.