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EGR valve

P0400 EGR valve not working properly

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P0400 means: EGR valve not working properly. The EGR valve sends part of the exhaust gas back into the engine. OK to drive, but have it checked soon. The repair usually costs about €80–600 in Estonia. The most common cause: EGR valve clogged with soot.

Is it safe to drive?OK to driveOK to drive, but have it checked soon.
Typical repair cost€80–600parts and labour in Estonia

What it means

The EGR valve sends part of the exhaust gas back into the engine. The engine computer thinks too little is flowing. Usually the valve or passage is clogged with soot.

What could be wrong

  1. 1EGR valve clogged with soot
  2. 2EGR passages blocked
  3. 3EGR cooler blocked
  4. 4Valve actuator has failed

What you can check yourself

If you mostly do short trips, take a longer motorway drive. If the code stays, the EGR needs cleaning. You can check the simple things yourself, but the repair is best done in a workshop.

How we fix it

  1. We check how the valve works with a diagnostic tool
  2. We clean the valve and passages
  3. We replace the valve if cleaning isn't enough

Standard SAE description: Exhaust Gas Recirculation Flow Malfunction

Want a definite answer?

Bring the car to our workshop in Estonia for diagnostics. We read the fault codes, test the sensors and tell you what is wrong. Repair price depends on the work involved, generally €45 per hour.

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Questions

What does fault code P0400 mean?

EGR valve not working properly. The EGR valve sends part of the exhaust gas back into the engine. The engine computer thinks too little is flowing. Usually the valve or passage is clogged with soot.

Can I drive with code P0400?

OK to drive, but have it checked soon.

How much does it cost to fix P0400?

Roughly €80–600 in Estonia. The price depends on exactly what has failed and on the car.

How is P0400 fixed?

We check how the valve works with a diagnostic tool. We clean the valve and passages. We replace the valve if cleaning isn't enough.

Related codes

P0401Too little gas flowing through the EGR valveP0402Too much gas flowing through the EGR valveP0403Fault in the EGR valve wiringP0404EGR valve isn't where it should beP0405EGR valve position sensor signal too lowP0406EGR valve position sensor signal too highP0411Secondary air pump not delivering enough airP0490Short circuit in the EGR valve wiring

Based on AI combined with our hands-on workshop experience and knowledge. This information is general and prices are approximate (Estonian workshop rates). The same code can mean different things on different cars. Only an inspection of the car gives a definite answer.

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