Konica Minolta Biz hub c450 code c-2558

[cartridgeprinter]

I have a customer with a Biz Hub c450. It have several error codes on it. After replacing all the imaging units and cleared all the codes except for c-2558.

I thought it had somethign to do with the Black imaging unit.

What is the error code and what do I need to do?

Thanks

[CMB]

the toner replenishing amount determination control.

C2558: Abnormally high toner density detected Black TCR Sensor