• Code: F2-40
• Description: Toner density sensor trouble (K)
• Causes: Toner density sensor output abnormality. Sensor connector and harness connection trouble. Developing unit trouble. PCU PWB trouble.
• Remedy: Replace the toner density sensor. Check connection of the sensor connector and the harness. Replace the developing unit. Replace the PCU PWB.

• Code: F2-41
• Description: Toner density sensor trouble (C)
• Causes: Toner density sensor output abnormality. Sensor connector and harness connection trouble. Developing unit trouble. PCU PWB trouble.
• Remedy: Replace the toner density sensor. Check connection of the sensor connector and the harness. Replace the developing unit. Replace the PCU PWB.

• Code: F2-42
• Description: Toner density sensor trouble (M)
• Causes: Toner density sensor output abnormality. Sensor connector and harness connection trouble. Developing unit trouble. PCU PWB trouble.
• Remedy: Replace the toner density sensor. Check connection of the sensor connector and the harness. Replace the developing unit. Replace the PCU PWB.

• Code: F2-43
• Description: Toner density sensor trouble (Y)
• Causes: Toner density sensor output abnormality. Sensor connector and harness connection trouble. Developing unit trouble. PCU PWB trouble
• Remedy: Replace the toner density sensor. Check connection of the sensor connector and the harness. Replace the developing unit. Replace the PCU PWB

• Code: F2-45
• Description: Color image density sensor trouble
• Causes: Image density sensor trouble. Image density sensor harness and PCU PWB connector connection trouble. Image density sensor dirt. Transfer belt cleaning trouble
• Remedy: Use SIM44-6 to execute the process control. Clean the image density sensor. Replace the image density sensor.

• Code: F2-49
• Description: LSU thermistor trouble
• Causes: The LSU temperature is outside of -28..C - 78..C. LSU thermistor trouble. LSU thermistor harness and connector connection trouble PCU PWB trouble. LSUcnt PWB trouble. LD PWB trouble
• Remedy: Check the harness and the connector connection at LSU thermistor. Replace the PCU PWB. Replace the LSU. Replace the LSUcnt PWB.

• Code: F2-50
• Description: K drum phase sensor trouble
• Causes: Drum phase sensor dirt. Drum phase sensor trouble. Drum phase sensor harness and connector connection trouble Drum drive section trouble. PCU PWB trouble.
• Remedy: Check the sensor condition and check the connection. Use SIM30-1 to check the operation of "DHPD_K". Replace the drum phase sensor. Repair the drum drive section. Replace the PCU PWB.

• Code: F2-51
• Description: C drum phase sensor trouble (C)
• Causes: Drum phase sensor dirt. Drum phase sensor trouble. Drum phase sensor harness and connector connection trouble Drum drive section trouble. PCU PWB trouble.
• Remedy: Check the sensor condition and check the connection. Use SIM30-1 to check the operation of "DHPD_CL". Replace the drum phase sensor. Repair the drum drive section. Replace the PCU PWB.