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P0401

Overview

Code

P0401

Code Type

P

Code Class

P0

System

Engine

Severity Level

Low

Emissions Related

true

Drivability Impact

None

Diagnostic Protocol

OBD2

Freeze Frame Useful

true

Code Definition

Diagnostic trouble code P0401 indicates insufficient EGR flow detected

Symptoms

Check Engine Light

Overview applies to this diagnostic code.

Affected Systems

On This Page

  • Code Definition

  • Symptoms

  • Affected Systems

  • Possible Causes

  • Diagnostic Steps

  • Drive Safety Notes​

More Resources

Exhaust gas recirculation system

Possible Causes

Carbon buildup in EGR valve

Diagnostic Steps

1 Inspect EGR valve for blockage; 2 Verify EGR command vs flow

Drive Safety Notes

Emissions increase if unresolved

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