OBD fault code library
Look up any P or U code to see what it means, what causes it, the parts involved and how it gets fixed.
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Fault codes
P0403
Exhaust Gas Recirculation Circuit Malfunction
Generic
Auxiliary Emissions Control
Medium severity
P0405
Exhaust Gas Recirculation Sensor A Circuit Low
Generic
Auxiliary Emissions Control
Medium severity
P0406
Exhaust Gas Recirculation Sensor A Circuit High
Generic
Auxiliary Emissions Control
Medium severity
P0407
Exhaust Gas Recirculation Sensor B Circuit Low
Generic
Auxiliary Emissions Control
Medium severity
P0409
Exhaust Gas Recirculation Sensor A Circuit
Generic
Auxiliary Emissions Control
Medium severity
P0410
Secondary Air Injection System Malfunction
Generic
Auxiliary Emissions Control
Medium severity
P0412
Secondary Air Injection System Switching Valve A Circuit Malfunction
Generic
Auxiliary Emissions Control
Medium severity
P0413
Secondary Air Injection System Switching Valve A Circuit Open
Generic
Auxiliary Emissions Control
Medium severity
P0415
Secondary Air Injection System Switching Valve B Circuit Malfunction
Generic
Auxiliary Emissions Control
Medium severity
P0416
Secondary Air Injection System Switching Valve B Circuit Open
Generic
Auxiliary Emissions Control
Medium severity
P0418
Secondary Air Injection System Relay A Circuit Malfunction
Generic
Auxiliary Emissions Control
Medium severity
P0419
Secondary Air Injection System Relay B Circuit Malfunction
Generic
Auxiliary Emissions Control
Medium severity
P0420
Catalyst System Efficiency Below Threshold Bank 1
Generic
Auxiliary Emissions Control
Medium severity
P0422
Main Catalyst Efficiency Below Threshold Bank
Generic
Auxiliary Emissions Control
Medium severity
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