P04xx codes — Auxiliary emission controls
249 generic powertrain trouble codes from P0400 to P04FF. Each links to its page: what it means, how serious it is, and how to fix it.
- P0400EGR A Flow
- P0401EGR A Flow Insufficient Detected
- P0402EGR A Flow Excessive Detected
- P0403EGR A Control Circuit/Open
- P0404EGR A Control Circuit Range/Performance
- P0405EGR Sensor A Circuit Low
- P0406EGR Sensor A Circuit High
- P0407EGR Sensor B Circuit Low
- P0408EGR Sensor B Circuit High
- P0409EGR Sensor A Circuit
- P040AEGR Temperature Sensor A Circuit
- P040BEGR Temperature Sensor A Circuit Range/Performance
- P040CEGR Temperature Sensor A Circuit Low
- P040DEGR Temperature Sensor A Circuit High
- P040EEGR Temperature Sensor A Circuit Intermittent/Erratic
- P040FEGR Temperature Sensor A/B Correlation
- P0410AIR System A
- P0411AIR System A Incorrect Flow Detected
- P0412AIR System Switching Valve A Circuit
- P0413AIR System Switching Valve A Circuit Open
- P0414AIR System Switching Valve A Circuit Shorted
- P0415AIR System Switching Valve B Circuit
- P0416AIR System Switching Valve B Circuit Open
- P0417AIR System Switching Valve B Circuit Shorted
- P0418AIR System Control A Circuit
- P0419AIR System Control B Circuit
- P041AEGR Temperature Sensor B Circuit
- P041BEGR Temperature Sensor B Circuit Range/Performance
- P041CEGR Temperature Sensor B Circuit Low
- P041DEGR Temperature Sensor B Circuit High
- P041EEGR Temperature Sensor B Circuit Intermittent/Erratic
- P041FAIR System Switching Valve A Circuit Low
- P0420Catalyst System Efficiency Below Threshold Bank 1
- P0421Catalyst 1 Efficiency Below Threshold Bank 1
- P0422Catalyst 2 Efficiency Below Threshold Bank 1
- P0423Heated Catalyst Efficiency Below Threshold Bank 1
- P0424Heated Catalyst Temperature Below Threshold Bank 1
- P0425Catalyst Temperature Sensor Circuit Bank 1 Sensor 1
- P0426Catalyst Temperature Sensor Circuit Range/Performance Bank 1 Sensor 1
- P0427Catalyst Temperature Sensor Circuit Low Bank 1 Sensor 1
- P0428Catalyst Temperature Sensor Circuit High Bank 1 Sensor 1
- P0429Catalyst Heater Control Circuit/Open Bank 1
- P042ACatalyst Temperature Sensor Circuit Bank 1 Sensor 2
- P042BCatalyst Temperature Sensor Circuit Range/Performance Bank 1 Sensor 2
- P042CCatalyst Temperature Sensor Circuit Low Bank 1 Sensor 2
- P042DCatalyst Temperature Sensor Circuit High Bank 1 Sensor 2
- P042EEGR A Control Stuck Open
- P042FEGR A Control Stuck Closed
- P0430Catalyst System Efficiency Below Threshold Bank 2
- P0431Catalyst 1 Efficiency Below Threshold Bank 2
- P0432Catalyst 2 Efficiency Below Threshold Bank 2
- P0433Heated Catalyst Efficiency Below Threshold Bank 2
- P0434Heated Catalyst Temperature Below Threshold Bank 2
- P0435Catalyst Temperature Sensor Circuit Bank 2 Sensor 1
- P0436Catalyst Temperature Sensor Circuit Range/Performance Bank 2 Sensor 1
- P0437Catalyst Temperature Sensor Circuit Low Bank 2 Sensor 1
- P0438Catalyst Temperature Sensor Circuit High Bank 2 Sensor 1
- P0439Catalyst Heater Control Circuit/Open Bank 2
- P043ACatalyst Temperature Sensor Circuit Bank 2 Sensor 2
- P043BCatalyst Temperature Sensor Circuit Range/Performance Bank 2 Sensor 2
- P043CCatalyst Temperature Sensor Circuit Low Bank 2 Sensor 2
- P043DCatalyst Temperature Sensor Circuit High Bank 2 Sensor 2
- P043EEVAP System Leak Detection Reference Orifice Low Flow
- P043FEVAP System Leak Detection Reference Orifice High Flow
- P0440EVAP System
- P0441EVAP System Incorrect Purge Flow
- P0442EVAP System Leak Detected (small leak)
- P0443EVAP System Purge Control Valve A Circuit
- P0444EVAP System Purge Control Valve A Circuit Open
- P0445EVAP System Purge Control Valve A Circuit Shorted
- P0446EVAP System Vent Control Circuit
- P0447EVAP System Vent Control Circuit Open
- P0448EVAP System Vent Control Circuit Shorted
- P0449EVAP System Vent Valve Control Circuit/Open
- P044AEGR Sensor C Circuit
- P044BEGR Sensor C Circuit Range/Performance
- P044CEGR Sensor C Circuit Low
- P044DEGR Sensor C Circuit High
- P044EEGR Sensor C Circuit Intermittent/Erratic
- P044FAIR System Switching Valve A Circuit High
- P0450EVAP System Pressure Sensor/Switch A Circuit
- P0451EVAP System Pressure Sensor/Switch A Circuit Range/Performance
- P0452EVAP System Pressure Sensor/Switch A Circuit Low
- P0453EVAP System Pressure Sensor/Switch A Circuit High
- P0454EVAP System Pressure Sensor/Switch A Circuit Intermittent
- P0455EVAP System Leak Detected - Large Leak
- P0456EVAP System Leak Detected (very small leak)
- P0457EVAP System Leak Detected (fuel cap loose/off)
- P0458EVAP System Purge Control Valve A Circuit Low
- P0459EVAP System Purge Control Valve A Circuit High
- P045AEGR B Control Circuit
- P045BEGR B Control Circuit Range/Performance
- P045CEGR B Control Circuit Low
- P045DEGR B Control Circuit High
- P045EEGR B Control Stuck Open
- P045FEGR B Control Stuck Closed
- P0460Fuel Level Sensor A Circuit
- P0461Fuel Level Sensor A Circuit Range/Performance
- P0462Fuel Level Sensor A Circuit Low
- P0463Fuel Level Sensor A Circuit High
- P0464Fuel Level Sensor A Circuit Intermittent
- P0465EVAP Purge Flow Sensor Circuit
- P0466EVAP Purge Flow Sensor Circuit Range/Performance
- P0467EVAP Purge Flow Sensor Circuit Low
- P0468EVAP Purge Flow Sensor Circuit High
- P0469EVAP Purge Flow Sensor Circuit Intermittent
- P046ACatalyst Temperature Sensor 1/2 Correlation Bank 1
- P046BCatalyst Temperature Sensor 1/2 Correlation Bank 2
- P046CEGR Sensor A Circuit Range/Performance
- P046DEGR Sensor A Circuit Intermittent/Erratic
- P046EEGR Sensor B Circuit Range/Performance
- P046FEGR Sensor B Circuit Intermittent/Erratic
- P0470Exhaust Pressure Sensor A Circuit
- P0471Exhaust Pressure Sensor A Circuit Range/Performance
- P0472Exhaust Pressure Sensor A Circuit Low
- P0473Exhaust Pressure Sensor A Circuit High
- P0474Exhaust Pressure Sensor A Circuit Intermittent/Erratic
- P0475Exhaust Pressure Control Valve A
- P0476Exhaust Pressure Control Valve A Range/Performance
- P0477Exhaust Pressure Control Valve A Low
- P0478Exhaust Pressure Control Valve A High
- P0479Exhaust Pressure Control Valve A Intermittent
- P047AExhaust Pressure Sensor B Circuit
- P047BExhaust Pressure Sensor B Circuit Range/Performance
- P047CExhaust Pressure Sensor B Circuit Low
- P047DExhaust Pressure Sensor B Circuit High
- P047EExhaust Pressure Sensor B Circuit Intermittent/Erratic
- P047FExhaust Pressure Control Valve A Stuck Open
- P0480Fan 1 Control Circuit
- P0481Fan 2 Control Circuit
- P0482Fan 3 Control Circuit
- P0483Fan Rationality Check
- P0484Fan Circuit Current High
- P0485Fan Power/Ground Circuit
- P0486EGR Sensor B Circuit
- P0487EGR Throttle Control Circuit A /Open
- P0488EGR Throttle Control Circuit A Range/Performance
- P0489EGR A Control Circuit Low
- P048AExhaust Pressure Control Valve A Stuck Closed
- P048BExhaust Pressure Control Valve A Position Sensor/Switch Circuit
- P048CExhaust Pressure Control Valve A Position Sensor/Switch Circuit Range/Performance
- P048DExhaust Pressure Control Valve A Position Sensor/Switch Circuit Low
- P048EExhaust Pressure Control Valve A Position Sensor/Switch Circuit High
- P048FExhaust Pressure Control Valve A Position Sensor/Switch Circuit Intermittent/Erratic
- P0490EGR A Control Circuit High
- P0491AIR System Insufficient Flow Bank 1
- P0492AIR System Insufficient Flow Bank 2
- P0493Fan Overspeed
- P0494Fan 1 Underspeed
- P0495Fan 1 Overspeed
- P0496EVAP System High Purge Flow
- P0497EVAP System Low Purge Flow
- P0498EVAP System Vent Valve Control Circuit Low
- P0499EVAP System Vent Valve Control Circuit High
- P049AEGR B Flow
- P049BEGR B Flow Insufficient Detected
- P049CEGR B Flow Excessive Detected
- P049DEGR A Control Position Exceeded Learning Limit
- P049EEGR B Control Position Exceeded Learning Limit
- P049FExhaust Pressure Control Valve B
- P04A0Exhaust Pressure Control Valve B Range/Performance
- P04A1Exhaust Pressure Control Valve B Low
- P04A2Exhaust Pressure Control Valve B High
- P04A3Exhaust Pressure Control Valve B Intermittent
- P04A4Exhaust Pressure Control Valve B Stuck Open
- P04A5Exhaust Pressure Control Valve B Stuck Closed
- P04A6Exhaust Pressure Control Valve B Position Sensor/Switch Circuit
- P04A7Exhaust Pressure Control Valve B Position Sensor/Switch Circuit Range/Performance
- P04A8Exhaust Pressure Control Valve B Position Sensor/Switch Circuit Low
- P04A9Exhaust Pressure Control Valve B Position Sensor/Switch Circuit High
- P04AAExhaust Pressure Control Valve B Position Sensor/Switch Circuit Intermittent/Erratic
- P04ABEVAP System Purge Control Valve B Circuit/Open
- P04ADEVAP System Purge Control Valve B Circuit High
- P04AEEVAP System Purge Control Valve B Performance/Stuck Open
- P04B0Refueling Vapor Control Valve Circuit/Open
- P04B1Refueling Vapor Control Valve Circuit Low
- P04B2Refueling Vapor Control Valve Circuit High
- P04B3Refueling Vapor Control Valve Stuck Performance/Stuck Open
- P04B4Refueling Vapor Control Valve Stuck Closed
- P04B5Fuel Fill Door Stuck Open
- P04B6Fuel Fill Door Stuck Closed
- P04B7Fuel Fill Door Position Sensor/Switch Circuit Intermittent/Erratic
- P04B8Fuel Fill Door Position Sensor/Switch Circuit
- P04B9Fuel Fill Door Position Sensor/Switch Circuit Low
- P04BAFuel Fill Door Position Sensor/Switch Circuit High
- P04BBFuel Fill Door Lock Control Circuit/Open
- P04BDFuel Fill Door Lock Control Circuit Low
- P04BEFuel Fill Door Lock Control Circuit High
- P04C0Fuel Fill Door Unlock Control Range/Performance
- P04C1Fuel Fill Door Unlock Control Circuit Low
- P04C2Fuel Fill Door Unlock Control Circuit High
- P04C3Fuel Fill Door Lock Position Sensor/Switch Circuit
- P04C4Fuel Fill Door Lock Position Sensor/Switch Circuit Range/Performance
- P04C5Fuel Fill Door Lock Position Sensor/Switch Circuit Low
- P04C6Fuel Fill Door Lock Position Sensor/Switch Circuit High
- P04C7Fuel Fill Door Lock Position Sensor/Switch Circuit Intermittent/Erratic
- P04C8Fuel Fill Door Open Request Sensor/Switch Circuit
- P04C9Fuel Fill Door Open Request Sensor/Switch Performance/Stuck Off
- P04CAFuel Fill Door Open Request Sensor/Switch Circuit Low
- P04CBFuel Fill Door Open Request Sensor/Switch Circuit High
- P04CCFuel Fill Door Open Request Sensor/Switch Circuit Intermittent/Erratic
- P04CDFuel Fill Door Open Request Sensor/Switch Stuck On
- P04CEEGR Temperature Sensor C Circuit
- P04D0EGR Temperature Sensor C Circuit Low
- P04D1EGR Temperature Sensor C Circuit High
- P04D2EGR Temperature Sensor C Circuit Intermittent/Erratic
- P04D3Exhaust Brake throttle valve mechanical or electrical fault detected
- P04D4Exhaust Brake Input Circuit Range/Performance
- P04D5Exhaust Brake Input Circuit Low
- P04D6Exhaust Brake Input Circuit High
- P04D7Exhaust Brake Input Circuit Intermittent/Erratic
- P04D8Excessive Time To Enter Closed Loop EGR Control
- P04D9Closed Loop EGR Control At Limit Flow Too Low
- P04DAClosed Loop EGR Control At Limit Flow Too High
- P04DBCrankcase Ventilation System Disconnected
- P04DDCold Start EGR A Flow Insufficient Detected
- P04DECold Start EGR A Flow Excessive Detected
- P04DFEVAP System Purge Control Valve A Performance/Stuck Open
- P04E0EVAP System Purge Control Valve A Stuck Closed
- P04E1Crankcase Ventilation Hose Connection Sensor Circuit
- P04E2Crankcase Ventilation Hose Connection Sensor Circuit Low
- P04E3Crankcase Ventilation Hose Connection Sensor Circuit High
- P04E4Crankcase Ventilation Hose Connection Sensor Circuit Intermittent/Erratic
- P04E5EGR Temperature Sensor D Circuit
- P04E6EGR Temperature Sensor D Circuit Range/Performance
- P04E7EGR Temperature Sensor D Circuit Low
- P04E8EGR Temperature Sensor D Circuit High
- P04E9EGR Temperature Sensor D Circuit Intermittent/Erratic
- P04EBEVAP System Small Leak Detected Fresh Air Side
- P04ECEVAP System Large Leak Detected Fuel Tank Side
- P04EDEVAP System Large Leak Detected Fresh Air Side
- P04EEEVAP System Very Small Leak Detected Fuel Tank Side
- P04EFEvap System Very Small Leak Detected - Fresh Air Side
- P04F0EVAP System High Load Purge Line A Performance
- P04F1EVAP System Purge Line Performance
- P04F2Catalyst Heater Supply Voltage Bank 1
- P04F3Catalyst Heater Supply Voltage Bank 2
- P04F4Catalyst Heater Circuit Low Bank 1
- P04F5Catalyst Heater Circuit Low Bank 2
- P04F6Catalyst Heater Circuit High Bank 1
- P04F7Catalyst Heater Circuit High Bank 2
- P04F8Catalyst Heater Circuit Intermittent Bank 1
- P04F9Catalyst Heater Circuit Intermittent Bank 2
- P04FAEGR A Control Temperature Too High
- P04FBCrankcase Ventilation Hose Connection Sensor Range/Performance
- P04FCCrankcase Ventilation System Performance Inadequate
- P04FDEGR Actuator A Control Processor Performance
- P04FECatalyst Heater Circuit Performance Bank 1
- P04FFCatalyst Heater Circuit Performance Bank 2