P0400
Exhaust Gas Recirculation Flow Malfunction
Generic code
Auxiliary Emissions Control
Medium severity
Moderate repair
Free on OBD DashX
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What P0400 means
- The fault code P0400 indicates that there is a malfunction in the Exhaust Gas Recirculation (EGR) system that may cause the engine to run poorly or not start at all.
Possible symptoms
- Illuminated check engine light
- Rough idle or stalling
- Reduced engine power or acceleration
- Increased emissions
Possible causes
- Clogged or dirty EGR valve
- Malfunctioning EGR valve
- Failed EGR solenoid
- Faulty wiring or connections in the EGR system
- Loose or corroded electrical connections
- Failed engine control module (ECM)
Related parts
- Exhaust Gas Recirculation (EGR) Sensor: Exhaust gas recirculation (EGR) is an emissions reduction technique used in petrol and diesel engines. Problems lead to harmful emissions out of limit
Possible solutions
- Clean or replace the EGR valve
- Replace the EGR solenoid
- Check and repair any damaged wiring or connections
- Tighten or clean any loose or corroded electrical connections
- Replace the engine control module (ECM) if necessary
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P0400 on OBD DashX
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