P04xx OBD2 Trouble Codes
This is the listing of P04xx OBD2 diagnostic trouble codes (DTCs). They all start with P04, e.g., P0404, P0454. The first letter P indicates that they are powertrain related codes, the next two digits 04 indicate they are auxiliary emissions related codes. The codes below are considered generic because they apply to all makes/models of OBD2 vehicles, although specific diagnosis & repair steps may vary.
P0400-P0499 Trouble Codes - Auxiliary Emissions Controls
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| Code(s) | Description |
|---|---|
| P0400 | Exhaust Gas Recirculation Flow Malfunction |
| P0401 | Exhaust Gas Recirculation Flow Insufficient Detected |
| P0402 | Exhaust Gas Recirculation Flow Excessive Detected |
| P0403 | Exhaust Gas Recirculation Circuit Malfunction |
| P0404 | Exhaust Gas Recirculation Circuit Range/Performance |
| P0405 | Exhaust Gas Recirculation Sensor A Circuit Low |
| P0406 | Exhaust Gas Recirculation Sensor A Circuit High |
| P0407 | Exhaust Gas Recirculation Sensor B Circuit Low |
| P0408 | Exhaust Gas Recirculation Sensor B Circuit High |
| P0409 | Exhaust Gas Recirculation Sensor "A" Circuit |
| P040A | Exhaust Gas Recirculation Temperature Sensor "A" Circuit |
| P040B | Exhaust Gas Recirculation Temperature Sensor "A" Circuit Range/Performance |
| P040C | Exhaust Gas Recirculation Temperature Sensor "A" Circuit Low |
| P040D | Exhaust Gas Recirculation Temperature Sensor "A" Circuit High |
| P040E | Exhaust Gas Recirculation Temperature Sensor "A" Circuit Intermittent/Erratic |
| P040F | Exhaust Gas Recirculation Temperature Sensor "A"/"B" Correlation |
| P0410 | Secondary Air Injection System Malfunction |
| P0411 | Secondary Air Injection System Incorrect Flow Detected |
| P0412 | Secondary Air Injection System Switching Valve A Circuit Malfunction |
| P0413 | Secondary Air Injection System Switching Valve A Circuit Open |
| P0414 | Secondary Air Injection System Switching Valve A Circuit Shorted |
| P0415 | Secondary Air Injection System Switching Valve B Circuit Malfunction |
| P0416 | Secondary Air Injection System Switching Valve B Circuit Open |
| P0417 | Secondary Air Injection System Switching Valve B Circuit Shorted |
| P0418 | Secondary Air Injection System Relay "A" Circuit Malfunction |
| P0419 | Secondary Air Injection System Relay "B" Circuit Malfunction |
| P041A | Exhaust Gas Recirculation Temperature Sensor "B" Circuit |
| P041B | Exhaust Gas Recirculation Temperature Sensor "B" Circuit Range/Performance |
| P041C | Exhaust Gas Recirculation Temperature Sensor "B" Circuit Low |
| P041D | Exhaust Gas Recirculation Temperature Sensor "B" Circuit High |
| P041E | Exhaust Gas Recirculation Temperature Sensor "B" Circuit Intermittent/Erratic |
| P041F | Secondary Air Injection System Switching Valve "A" Circuit Low |
| P0420 | Catalyst System Efficiency Below Threshold (Bank 1) |
| P0421 | Warm Up Catalyst Efficiency Below Threshold (Bank 1) |
| P0422 | Main Catalyst 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 (Bank 1, Sensor 1) |
| P0426 | Catalyst Temperature Sensor Range/Performance (Bank 1, Sensor 1) |
| P0427 | Catalyst Temperature Sensor Low (Bank 1, Sensor 1) |
| P0428 | Catalyst Temperature Sensor High (Bank 1, Sensor 1) |
| P0429 | Catalyst Heater Control Circuit (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 | Exhaust Gas Recirculation "A" Control Stuck Open |
| P042F | Exhaust Gas Recirculation "A" Control Stuck Closed |
| P0430 | Catalyst System Efficiency Below Threshold (Bank 2) |
| P0431 | Warm Up Catalyst Efficiency Below Threshold (Bank 2) |
| P0432 | Main Catalyst 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 Malfunction (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 (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 | Evaporative Emission System Leak Detection Reference Orifice Low Flow |
| P043F | Evaporative Emission System Leak Detection Reference Orifice High Flow |
| P0440 | Evaporative Emission Control System Malfunction |
| P0441 | Evaporative Emission Control System Incorrect Purge Flow |
| P0442 | Evaporative Emission Control System Leak Detected (small leak) |
| P0443 | Evaporative Emission Control System Purge Control Valve Circuit |
| P0444 | Evaporative Emission Control System Purge Control Valve Circuit Open |
| P0445 | Evaporative Emission Control System Purge Control Valve Circuit Shorted |
| P0446 | Evaporative Emission Control System Vent Control Circuit Malfunction |
| P0447 | Evaporative Emission Control System Vent Control Circuit Open |
| P0448 | Evaporative Emission Control System Vent Control Circuit Shorted |
| P0449 | Evaporative Emission Control System Vent Valve/Solenoid Circuit Malfunction |
| P044A | Exhaust Gas Recirculation Sensor "C" Circuit |
| P044B | Exhaust Gas Recirculation Sensor "C" Circuit Range/Performance |
| P044C | Exhaust Gas Recirculation Sensor "C" Circuit Low |
| P044D | Exhaust Gas Recirculation Sensor "C" Circuit High |
| P044E | Exhaust Gas Recirculation Sensor "C" Circuit Intermittent/Erratic |
| P044F | Secondary Air Injection System Switching Valve "A" Circuit High |
| P0450 | Evaporative Emission Control System Pressure Sensor Malfunction |
| P0451 | Evaporative Emission Control System Pressure Sensor Range/Performance |
| P0452 | Evaporative Emission Control System Pressure Sensor Low Input |
| P0453 | Evaporative Emission Control System Pressure Sensor High Input |
| P0454 | Evaporative Emission Control System Pressure Sensor Intermittent |
| P0455 | Evaporative Emission Control System Leak Detected (gross leak) |
| P0456 | Evaporative Emissions System Small Leak Detected |
| P0457 | Evaporative Emission Control System Leak Detected |
| P0458 | Evaporative Emission System Purge Control Valve Circuit Low |
| P0459 | Evaporative Emission System Purge Control Valve Circuit High |
| P045A | Exhaust Gas Recirculation "B" Control Circuit |
| P045B | Exhaust Gas Recirculation "B" Control Circuit Range/Performance |
| P045C | Exhaust Gas Recirculation "B" Control Circuit Low |
| P045D | Exhaust Gas Recirculation "B" Control Circuit High |
| P045E | Exhaust Gas Recirculation "B" Control Stuck Open |
| P045F | Exhaust Gas Recirculation "B" Control Stuck Closed |
| P0460 | Fuel Level Sensor Circuit Malfunction |
| P0461 | Fuel Level Sensor Circuit Range/Performance |
| P0462 | Fuel Level Sensor Circuit Low Input |
| P0463 | Fuel Level Sensor Circuit High Input |
| P0464 | Fuel Level Sensor Circuit Intermittent |
| P0465 | Purge Flow Sensor Circuit Malfunction |
| P0466 | Purge Flow Sensor Circuit Range/Performance |
| P0467 | Purge Flow Sensor Circuit Low Input |
| P0468 | Purge Flow Sensor Circuit High Input |
| P0469 | Purge Flow Sensor Circuit Intermittent |
| P046A | Catalyst Temperature Sensor 1/2 Correlation (Bank 1) |
| P046B | Catalyst Temperature Sensor 1/2 Correlation (Bank 2) |
| P046C | Exhaust Gas Recirculation Sensor "A" Circuit Range/Performance |
| P046D | Exhaust Gas Recirculation Sensor "A" Circuit Intermittent/Erratic |
| P046E | Exhaust Gas Recirculation Sensor "B" Circuit Range/Performance |
| P046F | Exhaust Gas Recirculation Sensor "B" Circuit Intermittent/Erratic |
| P0470 | Exhaust Pressure Sensor "A" Circuit |
| P0471 | Exhaust Pressure Sensor "A" Circuit Range/Performance |
| P0472 | Exhaust Pressure Sensor "A" Circuit Low |
| P0473 | Exhaust Pressure Sensor "A" Circuit High |
| P0474 | Exhaust Pressure Sensor "A" Circuit Intermittent |
| 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 |
| P0480 | Cooling Fan I Control Circuit Malfunction |
| P0481 | Cooling Fan 2 Control Circuit Malfunction |
| P0482 | Cooling Fan 3 Control Circuit Malfunction |
| P0483 | Cooling Fan Rationality Check Malfunction |
| P0484 | Cooling Fan Circuit Over Current |
| P0485 | Cooling Fan Power/Ground Circuit Malfunction |
| P0486 | Exhaust Gas Recirculation Sensor "B" Circuit |
| P0487 | Exhaust Gas Recirculation Throttle Control Circuit "A" Open |
| P0488 | Exhaust Gas Recirculation Throttle Control Circuit "A" Range/Performance |
| P0489 | Exhaust Gas Recirculation "A" Control Circuit Low |
| P048A | Exhaust Pressure Control Valve "A" Stuck Closed |
| P048B | Exhaust Pressure Control Valve Position Sensor/Switch Circuit |
| P048C | Exhaust Pressure Control Valve Position Sensor/Switch Circuit Range/Performance |
| P048D | Exhaust Pressure Control Valve Position Sensor/Switch Circuit Low |
| P048E | Exhaust Pressure Control Valve Position Sensor/Switch Circuit High |
| P048F | Exhaust Pressure Control Valve Position Sensor/Switch Circuit Intermittent/Erratic |
| P0490 | Exhaust Gas Recirculation "A" Control Circuit High |
| P0491 | Secondary Air Injection System Insufficient Flow Bank 1 |
| P0492 | Secondary Air Injection System Insufficient Flow Bank 2 |
| P0493 | Fan Overspeed |
| P0494 | Fan Speed Low |
| P0495 | Fan Speed High |
| P0496 | EVAP Flow During A Non-Purge Condition |
| P0497 | Evaporative Emission System Low Purge Flow |
| P0498 | Evaporative Emission System Vent Valve Control Circuit Low |
| P0499 | Evaporative Emission System Vent Valve Control Circuit High |
| P049A | Exhaust Gas Recirculation "B" Flow |
| P049B | Exhaust Gas Recirculation "B" Flow Insufficient Detected |
| P049C | Exhaust Gas Recirculation "B" Flow Excessive Detected |
| P049D | Exhaust Gas Recirculation "A" Control Position Exceeded Learning Limit |
| P049E | Exhaust Gas Recirculation "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 - P04FF | ISO/SAE Reserved |