Detects that it is being driven in the opposite direction to the specified driving direction.
The polarity of encoder cable is opposite.
The polarity of motor cable is opposite.
Encoder failure.
Irregular load.
Check points and solutions :
Check the connection between the PF Encoder Sensor and the Main Board Assy. Check if there is some foreign material causing extra load between the PF Motor and the PF roller. Replace the PF Encoder Sensor.