What P0400 means
Exhaust Gas Recirculation Flow Malfunction
Common causes (general)
Before spending money on parts, verify the code with a scan tool and read freeze frame data. Freeze frame captures every sensor value at the moment the code set — this is often enough to figure out the root cause without further testing.
Manufacturer-specific descriptions
Different manufacturers use this code for slightly different failure modes. Here's what your specific make means by P0400:
| BMW | Exhaust Gas Recirculation Flow |
| FORD | EGR Flow Malfunction |
| MITSUBISHI | Exhaust Gas Recirculation Flow Malfunction; EGR system |
| NISSAN | Exhaust Gas Recirculation Flow Malfunction |
| VOLKSWAGEN | Exhaust Gas Recirculation Flow Malfunction |
Read this code on your own car
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