John Deere fault codes & repair guides
All 3,995 codes· 50 per page · page 48 of 80
| Code | Controller | Issue summary | Repair manual |
|---|---|---|---|
| 004334.00 | — | DEF System Pressure High | Full repair manual for code 004334.00 |
| 004334.01 | — | DEF System Pressure Low | Full repair manual for code 004334.01 |
| 4334.01 | ECU | DEF Dosing Unit Pressure Extremely Low | Full repair manual for code 4334.01, ECU |
| 004334.03 | — | DEF System Pressure Sensor Voltage High (ECU) | Full repair manual for code 004334.03 |
| 4334.03 | Engine Control Unit (ECU) | DEF Dosing Unit Signal Out of Range High | Full repair manual for code 4334.03, Engine Control Unit (ECU) |
| 4334.04 | Engine Control Unit (ECU) | DEF Dosing Unit Signal Out of Range Low / DEF System Pressure Sensor Voltage Low | Full repair manual for code 4334.04, Engine Control Unit (ECU) |
| 4334.11 | Engine Control Unit (ECU) | DEF Dosing Unit Pressure Signal Fault | Full repair manual for code 4334.11, Engine Control Unit (ECU) |
| 004334.16 | — | DEF System Pressure Sensor Voltage High (ECU) | Full repair manual for code 004334.16 |
| 4334.16 | Engine Control Unit (ECU) | DEF Dosing Unit Pressure Moderately High | Full repair manual for code 4334.16, Engine Control Unit (ECU) |
| 004334.18 | — | DEF System Pressure Sensor Voltage Low (ECU) | Full repair manual for code 004334.18 |
| 4334.18 | ECU | DEF Dosing Unit Pressure Moderately Low | Full repair manual for code 4334.18, ECU |
| 004334.31 | — | DEF System Pressure Sensor Issue | Full repair manual for code 004334.31 |
| 4334.31 | ECU | DEF Dosing Unit Pressure Fault | Full repair manual for code 4334.31, ECU |
| 4341 | — | Dosing Unit Pressure Line Heater Fault | Full repair manual for code 4341 |
| 004341.05 | — | DEF Supply Pipe Heater Resistance Is High | Full repair manual for code 004341.05 |
| 4341.05 | ECU | DEF Dosing Unit Pressure Line Heater, Resistance Too High | Full repair manual for code 4341.05, ECU |
| 004341.06 | — | DEF Supply Pipe Heater Resistance Is Low | Full repair manual for code 004341.06 |
| 4341.06 | ECU | DEF Dosing Unit Pressure Line Heater, Resistance Too Low | Full repair manual for code 4341.06, ECU |
| 4343 | — | Dosing Unit Supply Line Heater Fault | Full repair manual for code 4343 |
| 004343.05 | — | DEF Supply Pipe Heater Resistance Is High | Full repair manual for code 004343.05 |
| 4343.05 | ECU | DEF Dosing Unit Line Heater Circuit Has High Resistance | Full repair manual for code 4343.05, ECU |
| 004343.06 | — | DEF Supply Pipe Heater Resistance Is Low | Full repair manual for code 004343.06 |
| 4343.06 | Engine Control Unit (ECU) | DEF Dosing Unit Return Line Heater, Resistance Too Low | Full repair manual for code 4343.06, Engine Control Unit (ECU) |
| 4345 | — | Dosing Unit Return Line Heater Fault | Full repair manual for code 4345 |
| 4345.05 | ECU | DEF Dosing Unit Supply Line Heater, Resistance Too High | Full repair manual for code 4345.05, ECU |
| 004345.06 | — | DEF Supply Pipe Heater Resistance Is Low | Full repair manual for code 004345.06 |
| 4345.06 | ECU | DEF Dosing Unit Return Line Heater Circuit Has Low Resistance | Full repair manual for code 4345.06, ECU |
| 4360 | — | Inlet Temperature Fault | Full repair manual for code 4360 |
| 004360.07 | — | Issue With The SCR Inlet Temperature Sensor | Full repair manual for code 004360.07 |
| 4360.07 | Engine Control Unit (ECU) | SCR Inlet Temperature Fault / SCR Inlet Temperature Invalid | Full repair manual for code 4360.07, Engine Control Unit (ECU) |
| 004360.12 | — | Issue With The SCR Inlet Temperature Sensor | Full repair manual for code 004360.12 |
| 4360.12 | Engine Control Unit (ECU) | SCR Inlet Temperature Faulty | Full repair manual for code 4360.12, Engine Control Unit (ECU) |
| 4363 | — | Outlet Temperature Fault | Full repair manual for code 4363 |
| 4364.01 | Engine Control Unit (ECU) | Catalytic Converter Efficiency of SCR System Extremely Low | Full repair manual for code 4364.01, Engine Control Unit (ECU) |
| 4364.17 | Engine Control Unit (ECU) | Catalytic Converter Efficiency of SCR System Slightly Low | Full repair manual for code 4364.17, Engine Control Unit (ECU) |
| 4364.18 | Engine Control Unit (ECU) / Engine Control Module (ECM) | Catalytic Converter Efficiency of SCR System Moderately Low | Full repair manual for code 4364.18, Engine Control Unit (ECU) / Engine Control Module (ECM) |
| 4366 | — | Tank Heater Coolant Valve Fault | Full repair manual for code 4366 |
| 004366.05 | — | DEF Tank Heater Solenoid Valve Low Amps (ECU) | Full repair manual for code 004366.05 |
| 4366.05 | ECU | DEF Tank Heater Coolant Control Valve Circuit Has High Resistance | Full repair manual for code 4366.05, ECU |
| 004366.06 | — | DEF Tank Heater Solenoid Valve High Amps | Full repair manual for code 004366.06 |
| 4366.06 | ECU / DCU | DEF Tank Heater Coolant Control Valve Circuit Has Low Resistance | Full repair manual for code 4366.06, ECU / DCU |
| 004366.16 | — | DEF Tank Temperature High. Heater Solenoid Valve Issue | Full repair manual for code 004366.16 |
| 4366.16 | ECU | DEF Tank Temperature Moderately High — DEF Tank Heater Coolant Control Valve is Stuck Open | Full repair manual for code 4366.16, ECU |
| 004366.18 | — | DEF Tank Temperature Too Low. Heater Solenoid Valve Issue. | Full repair manual for code 004366.18 |
| 4366.18 | ECU | DEF Tank Insufficient Heating Fault / DEF Tank Heater Coolant Control Valve is Stuck Closed | Full repair manual for code 4366.18, ECU |
| 4367.06 | ECU | The DEF Reverse Flow Solenoid Valve High Amps | Full repair manual for code 4367.06, ECU |
| 004376.05 | — | DEF Reverse Flow Solenoid Valve Low Amps (ECU) | Full repair manual for code 004376.05 |
| 4376.05 | ECU | DEF Dosing Unit Reversing Valve, Resistance Too High | Full repair manual for code 4376.05, ECU |
| 4376.14 | ECU | DEF Dosing System Powerdown Fault | Full repair manual for code 4376.14, ECU |
| 4490 | — | Intake Air Humidity Fault | Full repair manual for code 4490 |
