Error code canon 8180c e021 - Canon imageCLASS MF8180C All-In-One Laser Printer

SOURCE: Canon 8180C laser Multi Function printer Error Code 078

did you reset the drum unit on maintanance counter of the machine?

SOURCE: Canon ImageClass MF 8180c Error Code E071

i had the same problem, had to replace the drum unit

SOURCE: how to fix canon code E071

Here is an answer from DZJOLLA:
"hi there

well ive had years of experience on these machines and seen this error loads so ure in luck

1st off are u a tech? if not do not read any further as this post will only make sense to a tech.

i can only imagine this machine is old now. most of the time its the connectors that cause the e071 error. how many prints has copier done? have the connectors on the carraige frame and on frame of machine ever been changed? if not thats more than like causing your issue.

is your TD unit spinning ok? or is there resistence somewhere, if so this might also cause this error. the manual points to the 3 timing sensors in the TD unit IE. timing plates arent arriving on time for those sensors, but again everything relates back to the connectors as this is where it gets its voltage from. blow the sensors out as well.

change the connectors mate would be my 1st conclusion for that error let me know how u go please...

the other errors arent even coming up in the manual which points even more to the connectors.:

SOURCE: i have canon i-sensys MF 8180c with error E022. It

developing rotary drive mechanism fault Check the connector of the developing rotary drive sensor.
Check the connector of the drive motor.

SOURCE: canon 1120 error: E021/0201

One of this can be issue:

The developing locking motor
(PM1, PM2, PM3, PM4) is faulty.
• The developing assembly HP
sensor (PS49, PS51, PS53, PS55)
is faulty.
• The developing locking driver
PCB is faulty.
• The DC driver PCB is faulty.
• The CPU PCB is faulty.

You have problem :
When the developing
assembly is locked, the C
developing assembly HP
sensor is '1'.

I belive that problem is in developing section, best case scenario is that developer got on sensor, and you can vacume it.