OBD Fault Codes P0400-P0499 (Auxiliary Emissions Control)

Trouble codes between P0400 and P0499 relate to the auxiliary emissions control and related processes.


Click on each fault code number to read in more detail their meanings, potential causes and fixes.


Code

Meaning

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

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

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 Input (Bank 1 Sensor 1)

P0428

Catalyst Temperature Sensor High Input (Bank 1 Sensor 1)

P0429

Catalyst Heater Control Circuit (Bank 1)

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 (Bank 2 Sensor 1)

P0436

Catalyst Temperature Sensor Range/Performance (Bank 2 Sensor 1)

P0437

Catalyst Temperature Sensor Low Input (Bank 2 Sensor 1)

P0438

​Catalyst Temperature Sensor High Input (Bank 2 Sensor 1)

P0439

Catalyst Heater Control Circuit (Bank 2)

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 Malfunction

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

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 Tank Detected (gross leak)

P0456

Evaporative Emission System Leak Detected (very small leak)

P0457

Evaporative Emission System Leak Detected (fuel cap loose/off)

P0458

Evaporative Emission System Purge Control Valve Circuit Low

P0459

Evaporative Emission System Purge Control Valve Circuit High

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