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Home DTC Codes P0412 Medium · 30-60min
P0412 Warning

OBD2 Code P0412: Auxiliary Emissions (EGR, EVAP, Catalyst)

Emissions control system fault.

ECU: ECM

Detected Root Component

EGR Valve

Confidence level: medium

Technical Component Diagrams

EGR Valve Layout

EGR Valve Layout

Diag Expert technical diagram

EGR Valve Connector

EGR Valve Connector

Diag Expert technical diagram

Observed Symptoms

  • Engine light on (MIL/Check Engine)
  • Emissions exceeding standards
  • Excessive fuel consumption
  • Strong exhaust smell

Possible Causes

  • Clogged EGR valve
  • EGR channel clogged
  • Failed catalyst
  • Vacuum leak
  • Faulty solenoid valve
Diagnostic Progress 0 %
Difficulty Medium
Est. time 30-60min
Tools Required 5 tool(s)

Tools Required

multimeter OBD scanner wiring diagram test leads fuse puller

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Diagnostic Result

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Parts likely to be the cause (Moteur (général))

Moteur (général)

Moteur (général)

Photo d'illustration : Moteur (général)

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Frequently asked questions about code P0412

What does code P0412 mean?

OBD2 Code P0412: Auxiliary Emissions (EGR, EVAP, Catalyst). Emissions control system fault.

What are the symptoms of code P0412?

Code P0412 may cause: Engine light on (MIL/Check Engine), Emissions exceeding standards, Excessive fuel consumption, Strong exhaust smell. The intensity of these symptoms varies depending on the vehicle and driving conditions.

What causes code P0412?

The most common causes of code P0412 are: Clogged EGR valve, EGR channel clogged, Failed catalyst, Vacuum leak. A proper OBD2 diagnostic will pinpoint the exact cause.

Is it serious to drive with code P0412?

Code P0412 has moderate severity (Warning). Short-term driving remains possible, but a prompt check is recommended to prevent worsening.

How do I fix code P0412?

Start by reading the code with an OBD2 scanner, then follow the interactive decision tree on this page. Priority causes to check: Clogged EGR valve, EGR channel clogged, Failed catalyst, Vacuum leak. Difficulty: Medium · Estimated time: 30-60min.