P04xx codes — Auxiliary emission controls
256 codes in this group. The last column counts owner complaints that mention the code.
| Code | Meaning | Owner reports |
|---|---|---|
| P0400 | EGR A Flow | |
| P0401 | EGR A Flow Insufficient Detected | 3 |
| P0402 | EGR A Flow Excessive Detected | 3 |
| P0403 | EGR A Control Circuit/Open | 1 |
| P0404 | EGR A Control Circuit Range/Performance | 3 |
| P0405 | EGR Sensor A Circuit Low | 1 |
| P0406 | EGR Sensor A Circuit High | |
| P0407 | EGR Sensor B Circuit Low | |
| P0408 | EGR Sensor B Circuit High | |
| P0409 | EGR Sensor A Circuit | |
| P040A | EGR Temperature Sensor A Circuit | |
| P040B | EGR Temperature Sensor A Circuit Range/Performance | |
| P040C | EGR Temperature Sensor A Circuit Low | |
| P040D | EGR Temperature Sensor A Circuit High | |
| P040E | EGR Temperature Sensor A Circuit Intermittent/Erratic | |
| P040F | EGR Temperature Sensor A/B Correlation | |
| P0410 | AIR System A | |
| P0411 | AIR System A Incorrect Flow Detected | |
| P0412 | AIR System Switching Valve A Circuit | |
| P0413 | AIR System Switching Valve A Circuit Open | |
| P0414 | AIR System Switching Valve A Circuit Shorted | |
| P0415 | AIR System Switching Valve B Circuit | |
| P0416 | AIR System Switching Valve B Circuit Open | |
| P0417 | AIR System Switching Valve B Circuit Shorted | |
| P0418 | AIR System Control A Circuit | |
| P0419 | AIR System Control B Circuit | |
| P041A | EGR Temperature Sensor B Circuit | |
| P041B | EGR Temperature Sensor B Circuit Range/Performance | |
| P041C | EGR Temperature Sensor B Circuit Low | |
| P041D | EGR Temperature Sensor B Circuit High | |
| P041E | EGR Temperature Sensor B Circuit Intermittent/Erratic | |
| P041F | AIR System Switching Valve A Circuit Low | |
| P0420 | Catalyst System Efficiency Below Threshold Bank 1 | 186 |
| P0421 | Catalyst 1 Efficiency Below Threshold Bank 1 | |
| P0422 | Catalyst 2 Efficiency Below Threshold Bank 1 | |
| P0423 | Heated Catalyst Efficiency Below Threshold Bank 1 | |
| P0424 | Heated Catalyst Temperature Below Threshold Bank 1 | |
| P0425 | Catalyst Temperature Sensor Circuit Bank 1 Sensor 1 | |
| P0426 | Catalyst Temperature Sensor Circuit Range/Performance Bank 1 Sensor 1 | |
| P0427 | Catalyst Temperature Sensor Circuit Low Bank 1 Sensor 1 | |
| P0428 | Catalyst Temperature Sensor Circuit High Bank 1 Sensor 1 | |
| P0429 | Catalyst Heater Control Circuit/Open Bank 1 | |
| P042A | Catalyst Temperature Sensor Circuit Bank 1 Sensor 2 | |
| P042B | Catalyst Temperature Sensor Circuit Range/Performance Bank 1 Sensor 2 | |
| P042C | Catalyst Temperature Sensor Circuit Low Bank 1 Sensor 2 | |
| P042D | Catalyst Temperature Sensor Circuit High Bank 1 Sensor 2 | |
| P042E | EGR A Control Stuck Open | |
| P042F | EGR A Control Stuck Closed | |
| P0430 | Catalyst System Efficiency Below Threshold Bank 2 | 10 |
| P0431 | Catalyst 1 Efficiency Below Threshold Bank 2 | 1 |
| P0432 | Catalyst 2 Efficiency Below Threshold Bank 2 | |
| P0433 | Heated Catalyst Efficiency Below Threshold Bank 2 | |
| P0434 | Heated Catalyst Temperature Below Threshold Bank 2 | |
| P0435 | Catalyst Temperature Sensor Circuit Bank 2 Sensor 1 | |
| P0436 | Catalyst Temperature Sensor Circuit Range/Performance Bank 2 Sensor 1 | |
| P0437 | Catalyst Temperature Sensor Circuit Low Bank 2 Sensor 1 | |
| P0438 | Catalyst Temperature Sensor Circuit High Bank 2 Sensor 1 | |
| P0439 | Catalyst Heater Control Circuit/Open Bank 2 | |
| P043A | Catalyst Temperature Sensor Circuit Bank 2 Sensor 2 | |
| P043B | Catalyst Temperature Sensor Circuit Range/Performance Bank 2 Sensor 2 | |
| P043C | Catalyst Temperature Sensor Circuit Low Bank 2 Sensor 2 | |
| P043D | Catalyst Temperature Sensor Circuit High Bank 2 Sensor 2 | |
| P043E | EVAP System Leak Detection Reference Orifice Low Flow | |
| P043F | EVAP System Leak Detection Reference Orifice High Flow | |
| P0440 | EVAP System | |
| P0441 | EVAP System Incorrect Purge Flow | 14 |
| P0442 | EVAP System Leak Detected (small leak) | 2 |
| P0443 | EVAP System Purge Control Valve A Circuit | 1 |
| P0444 | EVAP System Purge Control Valve A Circuit Open | |
| P0445 | EVAP System Purge Control Valve A Circuit Shorted | 4 |
| P0446 | EVAP System Vent Control Circuit | 2 |
| P0447 | EVAP System Vent Control Circuit Open | 1 |
| P0448 | EVAP System Vent Control Circuit Shorted | 1 |
| P0449 | EVAP System Vent Valve Control Circuit/Open | |
| P044A | EGR Sensor C Circuit | |
| P044B | EGR Sensor C Circuit Range/Performance | |
| P044C | EGR Sensor C Circuit Low | |
| P044D | EGR Sensor C Circuit High | |
| P044E | EGR Sensor C Circuit Intermittent/Erratic | |
| P044F | AIR System Switching Valve A Circuit High | |
| P0450 | EVAP System Pressure Sensor/Switch A Circuit | 1 |
| P0451 | EVAP System Pressure Sensor/Switch A Circuit Range/Performance | 4 |
| P0452 | EVAP System Pressure Sensor/Switch A Circuit Low | |
| P0453 | EVAP System Pressure Sensor/Switch A Circuit High | 1 |
| P0454 | EVAP System Pressure Sensor/Switch A Circuit Intermittent | |
| P0455 | EVAP System Leak Detected - Large Leak | 13 |
| P0456 | EVAP System Leak Detected (very small leak) | 34 |
| P0457 | EVAP System Leak Detected (fuel cap loose/off) | 2 |
| P0458 | EVAP System Purge Control Valve A Circuit Low | |
| P0459 | EVAP System Purge Control Valve A Circuit High | |
| P045A | EGR B Control Circuit | |
| P045B | EGR B Control Circuit Range/Performance | |
| P045C | EGR B Control Circuit Low | |
| P045D | EGR B Control Circuit High | |
| P045E | EGR B Control Stuck Open | |
| P045F | EGR B Control Stuck Closed | |
| P0460 | Fuel Level Sensor A Circuit | |
| P0461 | Fuel Level Sensor A Circuit Range/Performance | 4 |
| P0462 | Fuel Level Sensor A Circuit Low | |
| P0463 | Fuel Level Sensor A Circuit High | 1 |
| P0464 | Fuel Level Sensor A Circuit Intermittent | 1 |
| P0465 | EVAP Purge Flow Sensor Circuit | |
| P0466 | EVAP Purge Flow Sensor Circuit Range/Performance | |
| P0467 | EVAP Purge Flow Sensor Circuit Low | |
| P0468 | EVAP Purge Flow Sensor Circuit High | |
| P0469 | EVAP Purge Flow Sensor Circuit Intermittent | |
| P046A | Catalyst Temperature Sensor 1/2 Correlation Bank 1 | |
| P046B | Catalyst Temperature Sensor 1/2 Correlation Bank 2 | |
| P046C | EGR Sensor A Circuit Range/Performance | |
| P046D | EGR Sensor A Circuit Intermittent/Erratic | |
| P046E | EGR Sensor B Circuit Range/Performance | |
| P046F | EGR Sensor B Circuit Intermittent/Erratic | |
| P0470 | Exhaust Pressure Sensor A Circuit | |
| P0471 | Exhaust Pressure Sensor A Circuit Range/Performance | 3 |
| P0472 | Exhaust Pressure Sensor A Circuit Low | |
| P0473 | Exhaust Pressure Sensor A Circuit High | |
| P0474 | Exhaust Pressure Sensor A Circuit Intermittent/Erratic | |
| P0475 | Exhaust Pressure Control Valve A | |
| P0476 | Exhaust Pressure Control Valve A Range/Performance | |
| P0477 | Exhaust Pressure Control Valve A Low | |
| P0478 | Exhaust Pressure Control Valve A High | |
| P0479 | Exhaust Pressure Control Valve A Intermittent | |
| P047A | Exhaust Pressure Sensor B Circuit | |
| P047B | Exhaust Pressure Sensor B Circuit Range/Performance | |
| P047C | Exhaust Pressure Sensor B Circuit Low | |
| P047D | Exhaust Pressure Sensor B Circuit High | |
| P047E | Exhaust Pressure Sensor B Circuit Intermittent/Erratic | |
| P047F | Exhaust Pressure Control Valve A Stuck Open | 3 |
| P0480 | Fan 1 Control Circuit | |
| P0481 | Fan 2 Control Circuit | |
| P0482 | Fan 3 Control Circuit | |
| P0483 | Fan Rationality Check | |
| P0484 | Fan Circuit Current High | |
| P0485 | Fan Power/Ground Circuit | |
| P0486 | EGR Sensor B Circuit | |
| P0487 | EGR Throttle Control Circuit A/Open | |
| P0488 | EGR Throttle Control Circuit A Range/Performance | |
| P0489 | EGR A Control Circuit Low | |
| P048A | Exhaust Pressure Control Valve A Stuck Closed | |
| P048B | Exhaust Pressure Control Valve A Position Sensor/Switch Circuit | |
| P048C | Exhaust Pressure Control Valve A Position Sensor/Switch Circuit Range/Performance | |
| P048D | Exhaust Pressure Control Valve A Position Sensor/Switch Circuit Low | |
| P048E | Exhaust Pressure Control Valve A Position Sensor/Switch Circuit High | |
| P048F | Exhaust Pressure Control Valve A Position Sensor/Switch Circuit Intermittent/Erratic | |
| P0490 | EGR A Control Circuit High | |
| P0491 | AIR System Insufficient Flow Bank 1 | 3 |
| P0492 | AIR System Insufficient Flow Bank 2 | |
| P0493 | Fan Overspeed | |
| P0494 | Fan 1 Underspeed | |
| P0495 | Fan 1 Overspeed | |
| P0496 | EVAP System High Purge Flow | 14 |
| P0497 | EVAP System Low Purge Flow | |
| P0498 | EVAP System Vent Valve Control Circuit Low | |
| P0499 | EVAP System Vent Valve Control Circuit High | |
| P049A | EGR B Flow | |
| P049B | EGR B Flow Insufficient Detected | |
| P049C | EGR B Flow Excessive Detected | |
| P049D | EGR A Control Position Exceeded Learning Limit | 1 |
| P049E | EGR B Control Position Exceeded Learning Limit | |
| P049F | Exhaust Pressure Control Valve B | |
| P04A0 | Exhaust Pressure Control Valve B Range/Performance | |
| P04A1 | Exhaust Pressure Control Valve B Low | |
| P04A2 | Exhaust Pressure Control Valve B High | |
| P04A3 | Exhaust Pressure Control Valve B Intermittent | |
| P04A4 | Exhaust Pressure Control Valve B Stuck Open | |
| P04A5 | Exhaust Pressure Control Valve B Stuck Closed | |
| P04A6 | Exhaust Pressure Control Valve B Position Sensor/Switch Circuit | |
| P04A7 | Exhaust Pressure Control Valve B Position Sensor/Switch Circuit Range/Performance | |
| P04A8 | Exhaust Pressure Control Valve B Position Sensor/Switch Circuit Low | |
| P04A9 | Exhaust Pressure Control Valve B Position Sensor/Switch Circuit High | |
| P04AA | Exhaust Pressure Control Valve B Position Sensor/Switch Circuit Intermittent/Erratic | |
| P04AB | EVAP System Purge Control Valve B Circuit/Open | |
| P04AC | EVAP System Purge Control Valve B Circuit Low | |
| P04AD | EVAP System Purge Control Valve B Circuit High | |
| P04AE | EVAP System Purge Control Valve B Performance/Stuck Open | |
| P04AF | EVAP System Purge Control Valve B Stuck Closed | |
| P04B0 | Refueling Vapor Control Valve Circuit/Open | |
| P04B1 | Refueling Vapor Control Valve Circuit Low | |
| P04B2 | Refueling Vapor Control Valve Circuit High | |
| P04B3 | Refueling Vapor Control Valve Performance/Stuck Open | |
| P04B4 | Refueling Vapor Control Valve Stuck Closed | |
| P04B5 | Fuel Fill Door Stuck Open | |
| P04B6 | Fuel Fill Door Stuck Closed | |
| P04B7 | Fuel Fill Door Position Sensor/Switch Circuit Intermittent/Erratic | |
| P04B8 | Fuel Fill Door Position Sensor/Switch Circuit | |
| P04B9 | Fuel Fill Door Position Sensor/Switch Circuit Low | |
| P04BA | Fuel Fill Door Position Sensor/Switch Circuit High | |
| P04BB | Fuel Fill Door Lock Control Circuit/Open | |
| P04BC | Fuel Fill Door Lock Control Range/Performance | |
| P04BD | Fuel Fill Door Lock Control Circuit Low | 1 |
| P04BE | Fuel Fill Door Lock Control Circuit High | |
| P04BF | Fuel Fill Door Unlock Control Circuit/Open | |
| P04C0 | Fuel Fill Door Unlock Control Range/Performance | |
| P04C1 | Fuel Fill Door Unlock Control Circuit Low | |
| P04C2 | Fuel Fill Door Unlock Control Circuit High | |
| P04C3 | Fuel Fill Door Lock Position Sensor/Switch Circuit | |
| P04C4 | Fuel Fill Door Lock Position Sensor/Switch Circuit Range/Performance | |
| P04C5 | Fuel Fill Door Lock Position Sensor/Switch Circuit Low | |
| P04C6 | Fuel Fill Door Lock Position Sensor/Switch Circuit High | |
| P04C7 | Fuel Fill Door Lock Position Sensor/Switch Circuit Intermittent/Erratic | |
| P04C8 | Fuel Fill Door Open Request Sensor/Switch Circuit | |
| P04C9 | Fuel Fill Door Open Request Sensor/Switch Performance/Stuck Off | |
| P04CA | Fuel Fill Door Open Request Sensor/Switch Circuit Low | |
| P04CB | Fuel Fill Door Open Request Sensor/Switch Circuit High | |
| P04CC | Fuel Fill Door Open Request Sensor/Switch Circuit Intermittent/Erratic | |
| P04CD | Fuel Fill Door Open Request Sensor/Switch Stuck On | |
| P04CE | EGR Temperature Sensor C Circuit | |
| P04CF | EGR Temperature Sensor C Circuit Range/Performance | |
| P04D0 | EGR Temperature Sensor C Circuit Low | |
| P04D1 | EGR Temperature Sensor C Circuit High | |
| P04D2 | EGR Temperature Sensor C Circuit Intermittent/Erratic | |
| P04D3 | Exhaust Brake Input Circuit | |
| P04D4 | Exhaust Brake Input Circuit Range/Performance | |
| P04D5 | Exhaust Brake Input Circuit Low | |
| P04D6 | Exhaust Brake Input Circuit High | |
| P04D7 | Exhaust Brake Input Circuit Intermittent/Erratic | |
| P04D8 | Excessive Time To Enter Closed Loop EGR Control | |
| P04D9 | Closed Loop EGR Control At Limit - Flow Too Low | |
| P04DA | Closed Loop EGR Control At Limit - Flow Too High | |
| P04DB | Crankcase Ventilation System Disconnected | 6 |
| P04DC | Fuel Fill Door Position Sensor/Switch Circuit Range/Performance | |
| P04DD | Cold Start EGR A Flow Insufficient Detected | |
| P04DE | Cold Start EGR A Flow Excessive Detected | |
| P04DF | EVAP System Purge Control Valve A Performance/Stuck Open | |
| P04E0 | EVAP System Purge Control Valve A Stuck Closed | |
| P04E1 | Crankcase Ventilation Hose Connection Sensor Circuit | |
| P04E2 | Crankcase Ventilation Hose Connection Sensor Circuit Low | |
| P04E3 | Crankcase Ventilation Hose Connection Sensor Circuit High | |
| P04E4 | Crankcase Ventilation Hose Connection Sensor Circuit Intermittent/Erratic | |
| P04E5 | EGR Temperature Sensor D Circuit | |
| P04E6 | EGR Temperature Sensor D Circuit Range/Performance | |
| P04E7 | EGR Temperature Sensor D Circuit Low | |
| P04E8 | EGR Temperature Sensor D Circuit High | |
| P04E9 | EGR Temperature Sensor D Circuit Intermittent/Erratic | |
| P04EA | EVAP System Small Leak Detected - Fuel Tank Side | |
| P04EB | EVAP System Small Leak Detected - Fresh Air Side | |
| P04EC | EVAP System Large Leak Detected - Fuel Tank Side | |
| P04ED | EVAP System Large Leak Detected - Fresh Air Side | |
| P04EE | EVAP System Very Small Leak Detected - Fuel Tank Side | |
| P04EF | EVAP System Very Small Leak Detected - Fresh Air Side | |
| P04F0 | EVAP System High Load Purge Line A Performance | 4 |
| P04F1 | EVAP System Purge Line Performance | |
| P04F2 | Catalyst Heater Supply Voltage Bank 1 | |
| P04F3 | Catalyst Heater Supply Voltage Bank 2 | |
| P04F4 | Catalyst Heater Circuit Low Bank 1 | |
| P04F5 | Catalyst Heater Circuit Low Bank 2 | |
| P04F6 | Catalyst Heater Circuit High Bank 1 | |
| P04F7 | Catalyst Heater Circuit High Bank 2 | |
| P04F8 | Catalyst Heater Circuit Intermittent Bank 1 | |
| P04F9 | Catalyst Heater Circuit Intermittent Bank 2 | |
| P04FA | EGR A Control Temperature Too High | |
| P04FB | Crankcase Ventilation Hose Connection Sensor Range/Performance | |
| P04FC | Crankcase Ventilation System Performance | |
| P04FD | EGR Actuator A Control Processor Performance | |
| P04FE | Catalyst Heater Circuit Performance Bank 1 | |
| P04FF | Catalyst Heater Circuit Performance Bank 2 |