• Code: H4-00
• Description: Fusing section low temperature trouble (TH_UM_AD2). The fusing temperature does not reach the specified level within the specified time from turning ON the power relay.
• Causes: Thermistor trouble. Heater lamp trouble. PCU PWB trouble. Thermostat trouble. Connector, harness connection trouble. HL control PWB trouble. Power unit trouble.
• Remedy: Use SIM14 to cancel the trouble. Use SIM44-14 to check the state of the thermistor. Use SIM5-2 to check the flashing operation of the heater lamp. Replace the thermistor. Replace the heater lamp. Replace the PCU PWB. Replace the thermostat. Check connection of the connector and the harness. Replace the HL control PWB. Replace the power unit.

• Code: H4-01
• Description: Fusing section low temperature trouble (TH_LM). The fusing temperature does not reach the specified level within the specified time from turning ON the power relay.
• Causes: Thermistor trouble. Heater lamp trouble. PCU PWB trouble. Thermostat trouble. Connector, harness connection trouble. HL control PWB trouble. Power unit trouble.
• Remedy: Use SIM14 to cancel the trouble. Use SIM44-14 to check the state of the thermistor. Use SIM5-2 to check the flashing operation of the heater lamp. Replace the thermistor. Replace the heater lamp. Replace the PCU PWB. Replace the thermostat. Check connection of the connector and the harness. Replace the HL control PWB. Replace the power unit.

• Code: H4-02
• Description: Fusing section low temperature trouble (TH_US) The fusing temperature does not reach the specified level within the specified time from turning ON the power relay
• Causes: Thermistor trouble. Heater lamp trouble. PCU PWB trouble. Thermostat trouble. Connector, harness connection trouble. HL control PWB trouble. Power unit trouble.
• Remedy: Use SIM14 to cancel the trouble. Use SIM44-14 to check the state of the thermistor. Use SIM05-02 to check the flashing operation of the heater lamp. Replace the thermistor. Replace the heater lamp. Replace the PCU PWB. Replace the thermostat. Check connection of the connector and the harness. Replace the HL control PWB. Replace the power unit.

• Code: H4-30
• Description: Upper main thermistor differential input abnormality (TH_UM) The values of TH_UM_AD1 and TH_UM_AD2 do not exceed the specified value within the specified time from turning ON the HL_UM.
• Causes: HL_UM does not turn on. Thermistor trouble. Harness trouble. PCU PWB trouble
• Remedy: Use SIM05-02 to check the flashing operation of the heater lamp. When the heater lamp flashes normally, check the thermistor and its harness. Check the thermistor input circuit section of the PCU PWB. When the lamp does not light up, check for disconnection in the heater lamp and breakage of the thermostat. Check the interlock switch. Check the lamp control circuit of the AC PWB and the PCU PWB. Use SIM14 to cancel the trouble.

• Code: H4-31
• Description: Lower main thermistor differential input abnormality (TH_LM1) The lower main compensation thermistor and the lower main differential thermistor do not exceed the specified value within the specified time from turning ON the lower main heater lamp.
• Causes: The lower main heater lamp does not turn ON. Thermistor breakdown, harness trouble, PCU PWB trouble
• Remedy: Use SIM05-02 to check the flashing operation of the heater lamp. When the heater lamp flashes normally, check the thermistor and its harness. Check the thermistor input circuit section of the PCU PWB. When the lamp does not light up, check for disconnection in the heater lamp and breakage of the thermostat. Check the interlock switch. Check the lamp control circuit of the AC PWB and the PCU PWB. Use SIM14 to cancel the trouble.

• Code: H4-32
• Description: Upper sub thermistor differential input abnormality (TH_US1) The upper sub compensation thermistor and the upper sub differential thermistor do not exceed the specified value within the specified time from turning ON the upper sub heater lamp.
• Causes: The upper sub heater lamp does not turn ON. Thermistor breakdown, harness trouble, PCU PWB trouble
• Remedy: Use SIM05-02 to check the flashing operation of the heater lamp. When the heater lamp flashes normally, check the thermistor and its harness. Check the thermistor input circuit section of the PCU PWB. When the lamp does not light up, check for disconnection in the heater lamp and breakage of the thermostat. Check the interlock switch. Check the lamp control circuit of the AC PWB and the PCU PWB. Use SIM14 to cancel the trouble.

• Code: H5-01
• Description: 5 times continuous POD1 not-reach jam
• Causes: A fusing jam is not canceled completely. (A jam paper remains.) POD1 sensor trouble Fusing unit installation trouble POD1 sensor connector and harness connection trouble PCU PWB trouble Fusing unit, drive section trouble
• Remedy: Replace the POD1 sensor. Check installation of the fusing unit. Replace the fusing unit. Check or repair the fusing drive section. Check connection of the POD1 sensor connector and the harness. Replace the PCU PWB. Use SIM14 to cancel the trouble.

• Code: H7-10
• Description: Recovery error from low fuser temp. (TH_UM_AD2) The fusing temperature does not reach the specified level within the specified time from stopping a job due to fall in the fusing temperature.
• Causes: Thermistor trouble. Heater lamp trouble. PCU PWB trouble. Thermostat trouble. Connector, harness connection trouble. HL control PWB trouble. Power unit trouble.
• Remedy: Replace the thermistor. Replace the heater lamp. Replace the PCU PWB. Replace the thermostat. Check connection of the connector and the harness. Replace the HL control PWB. Replace the power unit. Use SIM5-2 to check the flashing operation of the heater lamp.